document_title: Hash function

question_text: what type of key does a hashing algorithm use

question_tokens: what type of key does a hashing algorithm use

text: Hash function

text: Uses[edit]

text: Hash Tables[edit]

text: Hash functions are used in hash tables,[1] to quickly locate a data record (e.g., a dictionary definition) given its search key (the headword). Specifically, the hash function is used to map the search key to a list; the index gives the place in the hash table where the corresponding record should be stored. Hash tables, also, are used to implement associative arrays and dynamic sets.[2]

text: Typically, the domain of a hash function (the set of possible keys) is larger than its range (the number of different table indices), and so it will map several different keys to the same index. So then, each slot of a hash table is associated with (implicitly or explicitly) a set of records, rather than a single record. For this reason, each slot of a hash table is often called a bucket, and hash values are also called bucket listing[citation needed] or a bucket index.

text: Thus, the hash function only hints at the record's location. Still, in a half-full table, a good hash function will typically narrow the search down to only one or two entries.

text: People who write complete hash table implementations choose a specific hash function—such as a Jenkins hash or Zobrist hashing—and independently choose a hash-table collision resolution scheme—such as coalesced hashing, cuckoo hashing, or hopscotch hashing.

text: Caches[edit]

text: Hash functions are also used to build caches for large data sets stored in slow media. A cache is generally simpler than a hashed search table, since any collision can be resolved by discarding or writing back the older of the two colliding items. This is also used in file comparison.

text: Bloom filters[edit]

text: Hash functions are an essential ingredient of the Bloom filter, a space-efficient probabilistic data structure that is used to test whether an element is a member of a set.

text: Finding duplicate records[edit]

text: When storing records in a large unsorted file, one may use a hash function to map each record to an index into a table T, and to collect in each bucket T[i] a list of the numbers of all records with the same hash value i. Once the table is complete, any two duplicate records will end up in the same bucket. The duplicates can then be found by scanning every bucket T[i] which contains two or more members, fetching those records, and comparing them. With a table of appropriate size, this method is likely to be much faster than any alternative approach (such as sorting the file and comparing all consecutive pairs).

text: Protecting data[edit]

text: A hash value can be used to uniquely identify secret information. This requires that the hash function is collision-resistant, which means that it is very hard to find data that will generate the same hash value. These functions are categorized into cryptographic hash functions and provably secure hash functions. Functions in the second category are the most secure but also too slow for most practical purposes. Collision resistance is accomplished in part by generating very large hash values. For example, SHA-1, one of the most widely used cryptographic hash functions, generates 160 bit values.

text: Finding similar records[edit]

text: Hash functions can also be used to locate table records whose key is similar, but not identical, to a given key; or pairs of records in a large file which have similar keys. For that purpose, one needs a hash function that maps similar keys to hash values that differ by at most m, where m is a small integer (say, 1 or 2). If one builds a table T of all record numbers, using such a hash function, then similar records will end up in the same bucket, or in nearby buckets. Then one need only check the records in each bucket T[i] against those in buckets T[i+k] where k ranges between −m and m.

text: This class includes the so-called acoustic fingerprint algorithms, that are used to locate similar-sounding entries in large collection of audio files. For this application, the hash function must be as insensitive as possible to data capture or transmission errors, and to trivial changes such as timing and volume changes, compression, etc.[3]

text: Finding similar substrings[edit]

text: The same techniques can be used to find equal or similar stretches in a large collection of strings, such as a document repository or a genomic database. In this case, the input strings are broken into many small pieces, and a hash function is used to detect potentially equal pieces, as above.

text: The Rabin–Karp algorithm is a relatively fast string searching algorithm that works in O(n) time on average. It is based on the use of hashing to compare strings.

text: Geometric hashing[edit]

text: This principle is widely used in computer graphics, computational geometry and many other disciplines, to solve many proximity problems in the plane or in three-dimensional space, such as finding closest pairs in a set of points, similar shapes in a list of shapes, similar images in an image database, and so on. In these applications, the set of all inputs is some sort of metric space, and the hashing function can be interpreted as a partition of that space into a grid of cells. The table is often an array with two or more indices (called a grid file, grid index, bucket grid, and similar names), and the hash function returns an index tuple. This special case of hashing is known as geometric hashing or the grid method. Geometric hashing is also used in telecommunications (usually under the name vector quantization) to encode and compress multi-dimensional signals.

text: Standard uses of hashing in cryptography[edit]

text: Some standard applications that employ hash functions include authentication, message integrity (using an HMAC (Hashed MAC)), message fingerprinting, data corruption detection, and digital signature efficiency.

text: Properties[edit]

text: Good hash functions, in the original sense of the term, are usually required to satisfy certain properties listed below. The exact requirements are dependent on the application, for example a hash function well suited to indexing data will probably be a poor choice for a cryptographic hash function.

text: Determinism[edit]

text: A hash procedure must be deterministic—meaning that for a given input value it must always generate the same hash value. In other words, it must be a function of the data to be hashed, in the mathematical sense of the term. This requirement excludes hash functions that depend on external variable parameters, such as pseudo-random number generators or the time of day. It also excludes functions that depend on the memory address of the object being hashed in cases that the address may change during execution (as may happen on systems that use certain methods of garbage collection), although sometimes rehashing of the item is possible.

text: The determinism is in the context of the reuse of the function. For example, Python adds the feature that hash functions make use of a randomized seed that is generated once when the Python process starts in addition to the input to be hashed.[4] The Python hash is still a valid hash function when used in within a single run. But if the values are persisted (for example, written to disk) they can no longer be treated as valid hash values, since in the next run the random value might differ.

text: Uniformity[edit]

text: A good hash function should map the expected inputs as evenly as possible over its output range. That is, every hash value in the output range should be generated with roughly the same probability. The reason for this last requirement is that the cost of hashing-based methods goes up sharply as the number of collisions—pairs of inputs that are mapped to the same hash value—increases. If some hash values are more likely to occur than others, a larger fraction of the lookup operations will have to search through a larger set of colliding table entries.

text: Note that this criterion only requires the value to be uniformly distributed, not random in any sense. A good randomizing function is (barring computational efficiency concerns) generally a good choice as a hash function, but the converse need not be true.

text: Hash tables often contain only a small subset of the valid inputs. For instance, a club membership list may contain only a hundred or so member names, out of the very large set of all possible names. In these cases, the uniformity criterion should hold for almost all typical subsets of entries that may be found in the table, not just for the global set of all possible entries.

text: In other words, if a typical set of m records is hashed to n table slots, the probability of a bucket receiving many more than m/n records should be vanishingly small. In particular, if m is less than n, very few buckets should have more than one or two records. (In an ideal "perfect hash function", no bucket should have more than one record; but a small number of collisions is virtually inevitable, even if n is much larger than m – see the birthday paradox).

text: When testing a hash function, the uniformity of the distribution of hash values can be evaluated by the chi-squared test.

text: Defined range[edit]

text: It is often desirable that the output of a hash function have fixed size (but see below). If, for example, the output is constrained to 32-bit integer values, the hash values can be used to index into an array. Such hashing is commonly used to accelerate data searches.[5] On the other hand, cryptographic hash functions produce much larger hash values, in order to ensure the computational complexity of brute-force inversion.[2] For example, SHA-1, one of the most widely used cryptographic hash functions, produces a 160-bit value.

text: Producing fixed-length output from variable length input can be accomplished by breaking the input data into chunks of specific size. Hash functions used for data searches use some arithmetic expression which iteratively processes chunks of the input (such as the characters in a string) to produce the hash value.[5] In cryptographic hash functions, these chunks are processed by a one-way compression function, with the last chunk being padded if necessary. In this case, their size, which is called block size, is much bigger than the size of the hash value.[2] For example, in SHA-1, the hash value is 160 bits and the block size 512 bits.

text: Variable range[edit]

text: In many applications, the range of hash values may be different for each run of the program, or may change along the same run (for instance, when a hash table needs to be expanded). In those situations, one needs a hash function which takes two parameters—the input data z, and the number n of allowed hash values.

text: A common solution is to compute a fixed hash function with a very large range (say, 0 to 232 − 1), divide the result by n, and use the division's remainder. If n is itself a power of 2, this can be done by bit masking and bit shifting. When this approach is used, the hash function must be chosen so that the result has fairly uniform distribution between 0 and n − 1, for any value of n that may occur in the application. Depending on the function, the remainder may be uniform only for certain values of n, e.g. odd or prime numbers.

text: We can allow the table size n to not be a power of 2 and still not have to perform any remainder or division operation, as these computations are sometimes costly. For example, let n be significantly less than 2b. Consider a pseudorandom number generator (PRNG) function P(key) that is uniform on the interval [0, 2b − 1]. A hash function uniform on the interval [0, n-1] is n P(key)/2b. We can replace the division by a (possibly faster) right bit shift: nP(key) >> b.

text: Variable range with minimal movement (dynamic hash function)[edit]

text: When the hash function is used to store values in a hash table that outlives the run of the program, and the hash table needs to be expanded or shrunk, the hash table is referred to as a dynamic hash table.

text: A hash function that will relocate the minimum number of records when the table is – where z is the key being hashed and n is the number of allowed hash values – such that H(z,n + 1) = H(z,n) with probability close to n/(n + 1).

text: Linear hashing and spiral storage are examples of dynamic hash functions that execute in constant time but relax the property of uniformity to achieve the minimal movement property.

text: Extendible hashing uses a dynamic hash function that requires space proportional to n to compute the hash function, and it becomes a function of the previous keys that have been inserted.

text: Several algorithms that preserve the uniformity property but require time proportional to n to compute the value of H(z,n) have been invented.

text: A hash function with minimal movement is especially useful in distributed hash tables.

text: Data normalization[edit]

text: In some applications, the input data may contain features that are irrelevant for comparison purposes. For example, when looking up a personal name, it may be desirable to ignore the distinction between upper and lower case letters. For such data, one must use a hash function that is compatible with the data equivalence criterion being used: that is, any two inputs that are considered equivalent must yield the same hash value. This can be accomplished by normalizing the input before hashing it, as by upper-casing all letters.

text: Continuity[edit]

text: "A hash function that is used to search for similar (as opposed to equivalent) data must be as continuous as possible; two inputs that differ by a little should be mapped to equal or nearly equal hash values."[6]

text: Note that continuity is usually considered a fatal flaw for checksums, cryptographic hash functions, and other related concepts. Continuity is desirable for hash functions only in some applications, such as hash tables used in Nearest neighbor search.

text: Non-invertible[edit]

text: In cryptographic applications, hash functions are typically expected to be practically non-invertible, meaning that it is not realistic to reconstruct the input datum x from its hash value h(x) alone without spending great amounts of computing time (see also One-way function).

text: Hash function algorithms[edit]

text: For most types of hashing functions, the choice of the function depends strongly on the nature of the input data, and their probability distribution in the intended application.

text: Trivial hash function[edit]

text: If the data to be hashed is small enough, one can use the data itself (reinterpreted as an integer) as the hashed value. The cost of computing this "trivial" (identity) hash function is effectively zero. This hash function is perfect, as it maps each input to a distinct hash value.

text: The meaning of "small enough" depends on the size of the type that is used as the hashed value. For example, in Java, the hash code is a 32-bit integer. Thus the 32-bit integer Integer and 32-bit floating-point Float objects can simply use the value directly; whereas the 64-bit integer Long and 64-bit floating-point Double cannot use this method.

text: Other types of data can also use this perfect hashing scheme. For example, when mapping character strings between upper and lower case, one can use the binary encoding of each character, interpreted as an integer, to index a table that gives the alternative form of that character ("A" for "a", "8" for "8", etc.). If each character is stored in 8 bits (as in extended ASCII[7] or ISO Latin 1), the table has only 28 = 256 entries; in the case of Unicode characters, the table would have 17×216 = 7006111411200000000♠1114112 entries.

text: The same technique can be used to map two-letter country codes like "us" or "za" to country names (262 = 676 table entries), 5-digit zip codes like 13083 to city names (7005100000000000000♠100000 entries), etc. Invalid data values (such as the country code "xx" or the zip code 00000) may be left undefined in the table or mapped to some appropriate "null" value.

text: Perfect hashing[edit]

text: A hash function that is injective—that is, maps each valid input to a different hash value—is said to be perfect. With such a function one can directly locate the desired entry in a hash table, without any additional searching.

text: Minimal perfect hashing[edit]

text: A perfect hash function for n keys is said to be minimal if its range consists of n consecutive integers, usually from 0 to n−1. Besides providing single-step lookup, a minimal perfect hash function also yields a compact hash table, without any vacant slots. Minimal perfect hash functions are much harder to find than perfect ones with a wider range.

text: Hashing uniformly distributed data[edit]

text: If the inputs are bounded-length strings and each input may independently occur with uniform probability (such as telephone numbers, car license plates, invoice numbers, etc.), then a hash function needs to map roughly the same number of inputs to each hash value. For instance, suppose that each input is an integer z in the range 0 to N−1, and the output must be an integer h in the range 0 to n−1, where N is much larger than n. Then the hash function could be h = z mod n (the remainder of z divided by n), or h = (z × n) ÷ N (the value z scaled down by n/N and truncated to an integer), or many other formulas.

text: Hashing data with other distributions[edit]

text: These simple formulas will not do if the input values are not equally likely, or are not independent. For instance, most patrons of a supermarket will live in the same geographic area, so their telephone numbers are likely to begin with the same 3 to 4 digits. In that case, if m is 10000 or so, the division formula (z × m) ÷ M, which depends mainly on the leading digits, will generate a lot of collisions; whereas the remainder formula z mod m, which is quite sensitive to the trailing digits, may still yield a fairly even distribution.

text: Hashing variable-length data[edit]

text: When the data values are long (or variable-length) character strings—such as personal names, web page addresses, or mail messages—their distribution is usually very uneven, with complicated dependencies. For example, text in any natural language has highly non-uniform distributions of characters, and character pairs, very characteristic of the language. For such data, it is prudent to use a hash function that depends on all characters of the string—and depends on each character in a different way.

text: In cryptographic hash functions, a Merkle–Damgård construction is usually used. In general, the scheme for hashing such data is to break the input into a sequence of small units (bits, bytes, words, etc.) and combine all the units b[1], b[2], …, b[m] sequentially, as follows

text: This schema is also used in many text checksum and fingerprint algorithms. The state variable S may be a 32- or 64-bit unsigned integer; in that case, S0 can be 0, and G(S,n) can be just S mod n. The best choice of F is a complex issue and depends on the nature of the data. If the units b[k] are single bits, then F(S,b) could be, for instance

text: Here highbit(S) denotes the most significant bit of S; the '*' operator denotes unsigned integer multiplication with lost overflow; '^' is the bitwise exclusive or operation applied to words; and P is a suitable fixed word.[8]

text: Special-purpose hash functions[edit]

text: In many cases, one can design a special-purpose (heuristic) hash function that yields many fewer collisions than a good general-purpose hash function. For example, suppose that the input data are file names such as FILE0000.CHK, FILE0001.CHK, FILE0002.CHK, etc., with mostly sequential numbers. For such data, a function that extracts the numeric part k of the file name and returns k mod n would be nearly optimal. Needless to say, a function that is exceptionally good for a specific kind of data may have dismal performance on data with different distribution.

text: Rolling hash[edit]

text: In some applications, such as substring search, one must compute a hash function h for every k-character substring of a given n-character string t; where k is a fixed integer, and n is greater than k. The straightforward solution, which is to extract every such substring s of t and compute h(s) separately, requires a number of operations proportional to k·n. However, with the proper choice of h, one can use the technique of rolling hash to compute all those hashes with an effort proportional to k + n.

text: Universal hashing[edit]

text: A universal hashing scheme is a randomized algorithm that selects a hashing function h among a family of such functions, in such a way that the probability of a collision of any two distinct keys is 1/n, where n is the number of distinct hash values desired—independently of the two keys. Universal hashing ensures (in a probabilistic sense) that the hash function application will behave as well as if it were using a random function, for any distribution of the input data. It will, however, have more collisions than perfect hashing and may require more operations than a special-purpose hash function. See also unique permutation hashing.[9]

text: Hashing with checksum functions[edit]

text: One can adapt certain checksum or fingerprinting algorithms for use as hash functions. Some of those algorithms will map arbitrarily long string data z, with any typical real-world distribution—no matter how non-uniform and dependent—to a 32-bit or 64-bit string, from which one can extract a hash value in 0 through n − 1.

text: This method may produce a sufficiently uniform distribution of hash values, as long as the hash range size n is small compared to the range of the checksum or fingerprint function. However, some checksums fare poorly in the avalanche test, which may be a concern in some applications. In particular, the popular CRC32 checksum provides only 16 bits (the higher half of the result) that are usable for hashing.[citation needed][dubious – discuss] Moreover, each bit of the input has a deterministic effect on each bit of the CRC32 output; that is, one can tell without looking at the rest of the input which bits of the output will flip if the input bit is flipped, so care must be taken to use all 32 bits when computing the hash from the checksum.[10][dubious – discuss]

text: Multiplicative hashing[edit]

text: Multiplicative hashing is a simple type of hash function often used by teachers introducing students to hash tables.[11] Multiplicative hash functions are simple and fast, but have higher collision rates in hash tables than more sophisticated hash functions.[12]

text: In many applications, such as hash tables, collisions make the system a little slower but are otherwise harmless. In such systems, it is often better to use hash functions based on multiplication—such as MurmurHash and the SBoxHash—or even simpler hash functions such as CRC32—and tolerate more collisions; rather than use a more complex hash function that avoids many of those collisions but takes longer to compute.[12] Multiplicative hashing is susceptible to a "common mistake" that leads to poor diffusion—higher-value input bits do not affect lower-value output bits.[13]

text: Hashing with cryptographic hash functions[edit]

text: Some cryptographic hash functions, such as SHA-1, have even stronger uniformity guarantees than checksums or fingerprints, and thus can provide very good general-purpose hashing functions.

text: In ordinary applications, this advantage may be too small to offset their much higher cost.[14] However, this method can provide uniformly distributed hashes even when the keys are chosen by a malicious agent. This feature may help to protect services against denial of service attacks.

text: Hashing by nonlinear table lookup[edit]

text: This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2015) (Learn how and when to remove this template message)

tag: table

text: Tables of random numbers (such as 256 random 32-bit integers) can provide high-quality nonlinear functions to be used as hash functions or for other purposes such as cryptography. The key to be hashed is split into 8-bit (one-byte) parts, and each part is used as an index for the nonlinear table. The table values are then added by arithmetic or XOR addition to the hash output value. Because the table is just 1024 bytes in size, it fits into the cache of modern microprocessors and allows very fast execution of the hashing algorithm. As the table value is on average much longer than 8 bits, one bit of input affects nearly all output bits.

text: This algorithm has proven to be very fast and of high quality for hashing purposes (especially hashing of integer-number keys).

text: Efficient hashing of strings[edit]

text: Modern microprocessors will allow for much faster processing, if 8-bit character strings are not hashed by processing one character at a time, but by interpreting the string as an array of 32 bit or 64 bit integers and hashing/accumulating these "wide word" integer values by means of arithmetic operations (e.g. multiplication by constant and bit-shifting). The remaining characters of the string which are smaller than the word length of the CPU must be handled differently (e.g. being processed one character at a time).

text: This approach has proven to speed up hash code generation by a factor of five or more on modern microprocessors of a word size of 64 bit.[citation needed]

text: Another approach[15] is to convert strings to a 32 or 64 bit numeric value and then apply a hash function. One method that avoids the problem of strings having great similarity ("Aaaaaaaaaa" and "Aaaaaaaaab") is to use a Cyclic redundancy check (CRC) of the string to compute a 32- or 64-bit value. While it is possible that two different strings will have the same CRC, the likelihood is very small and only requires that one check the actual string found to determine whether one has an exact match. CRCs will be different for strings such as "Aaaaaaaaaa" and "Aaaaaaaaab". Although CRC codes can be used as hash values,[16] they are not cryptographically secure, because they are not collision-resistant.[17]

text: Locality-sensitive hashing[edit]

text: Locality-sensitive hashing (LSH) is a method of performing probabilistic dimension reduction of high-dimensional data. The basic idea is to hash the input items so that similar items are mapped to the same buckets with high probability (the number of buckets being much smaller than the universe of possible input items). This is different from the conventional hash functions, such as those used in cryptography, as in this case the goal is to minimize the probability of "collision" of every item.[18]

text: One example of LSH is MinHash algorithm used for finding similar documents (such as web-pages):

text: Let h be a hash function that maps the members of A and B to distinct integers, and for any set S define hmin(S) to be the member x of S with the minimum value of h(x). Then hmin(A) = hmin(B) exactly when the minimum hash value of the union A ∪ B lies in the intersection A ∩ B. Therefore,

text: In other words, if r is a random variable that is one when hmin(A) = hmin(B) and zero otherwise, then r is an unbiased estimator of J(A,B), although it has too high a variance to be useful on its own. The idea of the MinHash scheme is to reduce the variance by averaging together several variables constructed in the same way.

text: Origins of the term[edit]

text: The term "hash" offers a natural analogy with its non-technical meaning (to "chop" or "make a mess" out of something), given how hash functions scramble their input data to derive their output.[19] In his research for the precise origin of the term, Donald Knuth notes that, while Hans Peter Luhn of IBM appears to have been the first to use the concept of a hash function in a memo dated January 1953, the term itself would only appear in published literature in the late 1960s, on Herbert Hellerman's Digital Computer System Principles, even though it was already widespread jargon by then.[20]

text: List of hash functions[edit]

text:
NIST hash function competition
MD5
Bernstein hash[21]
Fowler-Noll-Vo hash function (32, 64, 128, 256, 512, or 1024 bits)
Jenkins hash function (32 bits)
Pearson hashing (8 or more bits)
Zobrist hashing

tag: ul


document_title: Roche (surname)

question_text: where does the last name roche come from

root

text: Roche (surname)

text: Roche is a surname of Norman origin. Notable people with this surname include:

tag: p

text:
The Roches, a female vocal group of sisters (Maggie and Terre and Suzzy Roche)
Roche baronets, baronetcy of Great Britain
Albert Severin Roche (1895-1939), French soldier
Alexander Roche, Baron Roche (1871-1956), British judge
Sir Boyle Roche, 1st Baronet, Irish politician and wit
Charlotte Roche (born 1978), German television presenter, actress, singer and author
Collette Roche, a British businesswoman who is the Chief Operating Officer at Manchester United Football Club
Daniel Roche (born 1999), English child actor
Danni Roche (born 1970), Australian field hockey player
David Roche (disambiguation), several people
Des Roche, 1930s NHL hockey player
Dick Roche (born 1947), Irish politician
Douglas Roche (born 1929), peace activist and former Canadian Senator
Édouard Roche (1820–1883), French scientist
Eric Roche (1967–2005), Irish fingerstyle guitarist
Ernest Roche (1850–1917), French engraver and socialist politician.
France Roche (1921–2013), a French film actress and screenwriter
Frank Roche  (born 1959), American writer
Jake Roche (born 1992), English singer-songwriter and actor and lead vocalist of Rixton
James G. Roche (born 1939), 20th Secretary of the United States Air Force
Joe Roche (born 1967), American columnist from Minnesota and Iraq War veteran
John Roche (disambiguation), various people
Jorge Roche (born 1957), Cuban gymnast who competed in the 1980 Summer Olympics
Juliette Roche (1884–1980), French painter and writer
Karl Roche (1862–1931), German syndicalist
Kevin Roche (born 1922), American architect
Michael Roche (disambiguation), several people
Mickaël Roche, Tahitian footballer
Nicolas Roche, an Irish cyclist
Raymond Roche, a French motorcyclist
Regina Maria Roche, an English Gothic Novelist
Shane Patrick Roche (born 1964), English actor, comedian, television presenter and singer better known as Shane Richie
Stephen Roche, an Irish cyclist and winner of the Triple Crown of Cycling
Tiger Roche, Irish soldier, adventurer and outlaw
Tony Roche (born 1945), Australian tennis player and coach
Tony Roche, Rugby Football Union journalist and father of Daniel Roche
William Roche (rugby union), Irish rugby union player

text: Surname listThis page lists people with the surname Roche. If an internal link intending to refer to a specific person led you to this page, you may wish to change that link by adding the person's given name(s) to the link.

text: SurnamesFrench-language surnamesAnglicised Irish-language surnames

text: Articles with short descriptionAll set index articles


document_title: Smart Fortwo

question_text: who makes the engine for the smart car

question_tokens: who makes the engine for the smart car

text: Smart Fortwo

text: History[edit]

text: The developments started before 1993 originally as Swatch car of Nicolas Hayek in co-operation with Volkswagen. The idea was to design a modern microcar with an electric or hybrid drive. VW, however, could not decide to production, which led to disputes with Hayek. Hayek then turned to Mercedes.

text: The company MCC (Micro Compact Car AG) was founded in 1994 by Hayek in Biel as a joint subsidiary of Daimler-Benz and SMH SA (Société Suisse de Microélectronique et d'Horlogerie). When MCC abandoned the original concept and the planned electric or hybrid drive, both Hayek and senior development team members left the project. "Today's gasoline-powered Smart is a product from Daimler-Benz and has not much in common with the plans of the former Swatch team."[7]

text: Design[edit]

text: The Fortwo is noted for its 2.5-metre (8.2 ft) – 2.69-metre (8.8 ft) overall length, high H-point seating, offset passenger and driver seats (in the first and second generation, the passenger seat is 15 centimetres further rearward than the driver’s),[8] automated manual transmission (1st and 2nd generation), De Dion tube rear suspension, low CO2 emissions (119 grams per kilometre, North America, 1.0 Liter),[9] two-part rear hatch, interchangeable plastic body panels and prominent steel hemispherical safety-cell, which is marketed as the Tridion cell and is often provided in a contrasting color to the vehicle's body panels.

text: Fortwo models are manufactured at Smartville—a dedicated Daimler assembly plant in Hambach, France—in Coupé (i.e., hatchback) and Cabrio (i.e., convertible) body styles, each in a mono-box configuration. Generations are internally designated as the W450 build series, introduced at the 1998 Paris Motor Show, and the W451 build series, introduced at the 2006 Bologna Motor Show.[10] Smartville underwent a 200 million euro upgrade beginning in mid-2013 for the third generation Fortwo (2014–), internally designated as the C453 build series.[5][11] The third generation Fortwo made its formal global debut on July 16, 2014[12] at the Tempodrom in Berlin[13] along with a closely related four-door version, the Smart Forfour, co-developed and sharing the same platform and engines with the third generation Renault Twingo.

text: With the second generation, Smart introduced a version with automatic start-stop, marketed as the MHD, or Micro-Hybrid Drive—offered only in certain markets. A sport model, marketed as the Brabus model, has been available in both generations, and Daimler introduced the Smart electric drive, an all-electric version, in 2007.[14][15] The Fortwo forms the basis for Daimler's Car2go fleet, the largest car-sharing enterprise worldwide.[3]

text: In 2002, the New York Museum of Modern Art (MoMa) introduced a first generation Fortwo into its permanent collection (the only vehicle to be included into the collection while still in series production),[16] and in 2014 the Fortwo was voted the Best Microcar for the fifth year in a row by readers of the Chinese edition of Auto, Motor und Sport.[17] At the time of its commercial launch, the Smart Fortwo diesel-engined variant, the Cdi, had the world's lowest carbon dioxide emissions for an internal combustion engine, at 88 grams per kilometer rated NEDC cycle.[18]

text: Features[edit]

text: The 2001 marketing brochure for the W450 build series cites a .37 drag coefficient. Auto, Motor und Sport cites a drag coefficient (Cd) of .35 and Alles Auto cites a Cd of .345 for the second generation W451 series[19][20] For comparison, the current Fiat 500 offers a .38 Cd and the first generation Honda Insight offers a Cd of .29. The W450 and W451 series each have a frontal area of 1.95 square metres (21.0 sq ft) and 2.057 square metres (22.14 sq ft) respectively.

text: Transmissions[edit]

text: The first and second generation Fortwo models employ an automated manual transmission, designed and manufactured by Getrag, where the clutch is computer controlled, eliminating the clutch pedal. The first generation used a six-speed version, and the second generation uses a five-speed version, model 5AMT130. Input from floor-mounted shifter or optional steering-wheel-mounted paddles controls a servo-operated clutch and sequential automated gearbox. The vehicle may be driven in automatic mode (early models had the option of full automatic mode, or standard "soft-tip" which was manual mode indicated by no button on the gear lever) or via paddle shifters, where the operator controls the shift points but cannot feather or adjust the speed of the clutch.

text: From 2009, revised transmission software enabled smoother and faster gear changes. The software, available via an ECU upgrade, was also made available for 2008 second generation cars, with a new battery as required.[21][22]

text: Third generation models receive a five-speed manual transmission or dual clutch automated manual transmission.

text: Parking[edit]

text: With an overall length (first generation: 2.5 m (98.4 in)) approximately equal to the width of regular parking space, a smart Fortwo can park perpendicularly in spaces typically designed for parallel parking, allowing two Smarts to park in one space—a manner of parking not permissible in many jurisdictions worldwide (e.g. Austria, New Zealand and California[23]).

text: First generation (Build series W450, 1998–2007)[edit]

text:
First generation (W450)

Overview

Also called
Smart City Coupé (1998–2002)
Smart Fortwo (facelift)

Production
1998–2007

Body and chassis

Body style
3-door hatchback

Powertrain

Engine
0.6 L petrol (turbo) I3
0.7 L petrol (turbo) I3
0.8 L diesel (turbo) I3

Transmission
6-speed semi-automatic

Dimensions

Wheelbase
1,810 mm (71.3 in)

Length
2,500 mm (98.4 in)

Width
1,510 mm (59.6 in)

Height
1,500 mm (61 in)

Curb weight
1,610 lb (730 kg)

text: The first generation, build series W450, debuted in 1998 and received a facelift in 2002.

text: Engine[edit]

text: The engines are turbocharged with three cylinders. Originally the basic petrol engine was 599 cc, and came in three versions—45 hp (33 kW), 51 hp (38 kW) and 61 hp (45 kW). The engine displacement was increased to 698 cc with the facelift in 2002, in 37 kW (50 hp) and 45 kW (61 hp) variants. The turbo-diesel engine had 799 cc displacement giving 30 kW (41 hp).

text: Models[edit]

text: The Fortwo is available as a coupe or cabriolet, originally called the "city coupe" & "city cabrio", now the "Fortwo" & "Fortwo cabrio", introduced in 2000 and restyled in 2002. Trim levels include the Pure, Pulse, and Passion. Pure models are fitted with the standard audio system but nothing else, Pulse models are fitted with alloy wheels, panoramic glass roof and paddle-shifters on the steering wheel (2004+), and finally, the Passion models are fitted with air-conditioning and ability to select between fully automatic and sequential gearbox.

text:
Limited 1: The first limited edition of which 7500 were made. All left-hand drive. Released at the original launch in 1998. Black Tridion cell and White body panels. Alloy wheels, Limited 1 insignia, blue interior with beige leather finishings. Supplied with certificate showing which number out of the 7500, and a plaque with this number below the windshield on the inside.
SE: This was the second limited edition that smart made, it was sold in mid 2001 (Mk5) and all were left hand drive. They were all Pulse specification with a redesigned steering wheel, soft touch, air conditioning, CD Multichanger and drinks holder as standard. The engine power was upped to 61BHP from the standard 55BHP normally applied to the Pulse in the 600cc G1 cars. It was designated by a SE badge on the boot and was sold in Bay Grey with grey interior and dark blue twist fabric.
Cdi: has the world's smallest production common-rail direct injection diesel engine. With a consumption of 3.3 litres (NEDC) per 100 kilometres (71.2 mpg) and CO2 emissions of just 88 grams per kilometre, it has the lowest current production car CO2 emissions worldwide, since Audi and Volkswagen retired its 3-cylinder cars, the A2 1.2 TDI and the Lupo 1.2 TDI respectively.[24]
Crossblade: a 2002 limited-edition variant of the city cabrio, a roadster without a windshield, roof or conventional doors. Its weight was still 740 kilograms (1,630 lb). The Brabus-tuned engine developed 52 kW (71 PS) from its 599 cc engine. After Robbie Williams purchased Crossblade number 008, Smart began a marketing association with him, using him to promote the brand and the new Forfour.
Crosstown: a convertible with a foldable windshield based on the Fortwo, was presented at IAA Frankfurt in 2005. No plans have been announced to bring this model to market.
Nightrun: includes instrument panels, steering wheel, paddles, shifter, Monoblock VI alloy wheels, leather seats and engine upgrade from Brabus. Edition Nightrun is only available with the Fortwo coupé/cabrio.
Truestyle: painted in metallic ruby red, available in pure trim.
i-move: a special edition run of 70 Fortwo cabrios, based on the Passion cabrio specs with Brabus Monobloc VI wheels, leather interior trim, Lite White panels, an iPod cradle with special edition 20Gb 3G iPod, and an aluminium name plate on the dash confirmed its special edition status.
Forfun2 Concept: an off-road version of the Fortwo introduced at the 2005 Athens Motor Show by Greek 4x4 Rally Champion Stefan Attart. It combines the body of a Fortwo with the chassis and drivetrain of a Unimog. It sports monster truck-like 26-inch (66 cm) wheels wrapped in 1.4-metre (4.6 ft) diameter tires and winding keys where the Fortwo's rear wheels are supposed to be.[25][26]
Brabus: In 2003 Smart and Brabus introduced the jointly developed version of the Fortwo with the 698cc engine. It had 75 PS (55 kW; 74 hp) of power and 110 Nm of torque. It was available in both coupe and convertible versions. It also featured wider wheels, revised front spoiler and grille, and a revised rear exhaust.
K: launched in October 2001, exclusively for the Japanese market. It was designed to fit the Japanese kei car regulations by adopting specially developed rear fenders and narrowing the track width and tire dimensions and the width reduced to 1.47 m. The engine displacement remains unchanged at 598 cc, as specified in the standard. Safety features include ESP (Electronic Stability Program) and BAS (Brake Assist System) as standard. The Smart K also facilitates the starting procedure with the Hill Start Assist that makes a starts on slopes easier.[27] The Smart K was discontinued in November 2004.[citation needed]
Fortwo Edition Limited One: Featured special metallic grey body panels; silver Tridion cell; brown leather for the seating, steering wheel, and shift lever—along with matching floor mats. The model marked the launch of the W451 build series.

text: Gallery[edit]

text:
One of four BRABUS Canada 1 cdi cars in Canada

Coupe

Convertible

Tachometer generation 450 and clock

Smart Crossblade

2002 Smart Fortwo BRABUS

2002 facelift

2002 facelift

Japanese market Smart K

text: Second generation (Build series W451, 2007–2014)[edit]

text:
Second generation (W451)

Overview

Production
2007–2014

Body and chassis

Body style
3-door hatchback

Powertrain

Engine
0.8 L diesel (turbo) I3
1.0 L petrol I3
1.0 L petrol (turbo) I3

Transmission
5-speed semi-automatic

Dimensions

Wheelbase
1,870 mm (73.5 in) (2008–10)
1,867 mm (73.5 in) (2011–)

Length
2,690 mm (106.1 in) (2008–10)
2,695 mm (106.1 in) (2011–)

Width
1,560 mm (61.4 in) (2008–10)
1,559 mm (61.4 in) (2011–)

Height
1,540 mm (60.7 in) (2008–10)
1,542 mm (60.7 in) (2011–)

Kerb weight
750–795 kg (1,653–1,753 lb) (coupe)
780–820 kg (1,720–1,808 lb) (cabrio)

text: The second generation, build series W451 (internally: C 451, Coupé – A 451, Cabrio), was introduced in November 2006—its length increased by 200 mm to 2,690 mm (106.1 in) and offering improved crash performance. The second generation retained the interchangeable plastic body panels as well as the prominent exposed, rigid steel safety cell, which is 50% high-strength steel, hot-dip galvanised and powder-coated—and marketed as Tridion.

text: The range received a minor interior facelift for model year 2011 with standard knee airbags, new instrument cluster, more extensive cloth trimming for the top of the instrument panel, circular rather than rectangular outboard dash vents, optional multimedia system with a 6.5" display, and optional surround-sound audio system. For model year 2013 all Fortwo's received a minor exterior facelift with revised lower facias, front and rear, and a relocated brand emblem located inside rather than above the front grille.[28]

text: The second generation Fortwo remained the lightest production car on sale in Europe.[29]

text: Engine and fuel economy[edit]

text: The 999 cc I3 Mitsubishi 3B2 engine (2007 onwards) is offered in normally aspirated and turbo versions. German tuner company Brabus, in a joint venture with Smart, has developed a high powered version of the 1.0-litre turbo, producing 102 PS (75 kW; 101 bhp), originally available only in Europe, but now available elsewhere. A small 0.8-litre three-cylinder turbo diesel common rail engine made by Mercedes was available in most European markets.

text: European Union (EU) fuel consumption testing for the combined cycle rates the 1.0-litre mhd at 65.7 mpg‑imp (4.30 L/100 km; 54.7 mpg‑US), the turbo at 57.6 mpg‑imp (4.90 L/100 km; 48.0 mpg‑US) and 85.6 mpg‑imp (3.30 L/100 km; 71.3 mpg‑US) for the diesel.[30] The U.S. Environmental Protection Agency (EPA) rates the 1.0-litre mhd at 36 mpg‑US (6.5 L/100 km; 43 mpg‑imp) combined (the EPA does not offer a rating for the diesel engine).[31]

text: At the 2007 Frankfurt Motor Show, Smart debuted the "micro hybrid drive" (mhd) version of the Fortwo, which was subsequently launched in the UK in 2008. The technology features an automated start-stop system, and a belt-driven starter-generator, which replaces both the starter and alternator. The system generates electricity to charge the battery when the driver is braking, and automatically cuts the engine when the speed drops below 5 mph (8 km/h).[32] Smart claims a fuel efficiency improvement of eight percent from 50 miles per US gallon (4.7 L/100 km; 60 mpg‑imp) to almost 55 miles per US gallon (4.3 L/100 km; 66 mpg‑imp) on the slow NEDC drive cycle—with a reduction in Carbon dioxide emissions from 112 to 103 g/km.[24] This was further improved to 97 g/km in 2010. The mhd version of the Fortwo is not available in the United States or Canada.

text:
Engine
Capacity
Power
Torque
Emissions CO2
Top Speed
0-100 km/h (62 mph)

0.8 cdi (diesel)
799 cm3
54 PS (40 kW; 53 bhp)
130 N⋅m (96 lb⋅ft)
86 g/km
84 mph (135 km/h)
16.8 s

1.0 mhd (petrol)
999 cm3
71 PS (52 kW; 70 bhp)
92 N⋅m (68 lb⋅ft)
97 g/km (130 g/km in NA)
90 mph (145 km/h)
10.7 s

1.0 turbo (petrol)
999 cm3
84 PS (62 kW; 83 bhp)
120 N⋅m (89 lb⋅ft)
115 g/km
90 mph (145 km/h)
9.9 s

1.0 Brabus (petrol)
999 cm3
102 PS (75 kW; 101 bhp)
147 N⋅m (108 lb⋅ft)
119 g/km
96 mph (154 km/h)
8.9 s

text: Safety[edit]

text: At introduction, the second generation featured front airbags as well as seat-mounted combination head/thorax side airbags along with the tridion cell, seat belt tensioners, anti-lock brakes, brake force distribution and electronic stability control. In the United States from model year 2012 onward, the Fortwo featured a total of eight dual-stage airbags in the Coupe—front, knee, side (thorax/pelvis) and window curtain—and a total of six dual-stage airbags in the Cabrio model—front, knee, side (thorax/head) dual-stage airbags. As a part of the vehicle's tridion cell and crash management system, the front crumple zone is maximized by the rear-mounted engine location.

text: In Insurance Institute for Highway Safety (IIHS) tests, the 2008 Smart Fortwo earned the top overall rating of "Good" in both the front and side crash tests. The Fortwo received the "Good" score in 8 of 11 measured injury categories.[33] Its seat/head restraints earned the second highest rating of "Acceptable" for protection against whiplash in rear impacts. The IIHS did an offset crash test with a Smart Fortwo and Mercedes-Benz C-Class, which is 40% of one car's driver's side head on with 40% of another car's driver's side, and the Smart received a "Poor" rating due to the occupants' heads slamming into the steering wheel. Also, there was too much intrusion into the footwell of the Smart Fortwo. The dummy movement was not well controlled. The Smart Fortwo spun 450 degrees in the air upon impact.[34]

text:
The Fortwo in its stand-alone IIHS crash test

The Fortwo crashed into a Mercedes-Benz C-Class

text: U.S. National Highway Traffic Safety Administration (NHTSA) crash test results for the 2008 Smart Fortwo:[35]

text:
Frontal Driver:
Frontal Passenger:
Side Driver:  *The driver door unlatched and opened during the side impact crash which increases the likelihood of occupant ejection.
Rollover:

text: Euro NCAP crash results:[36]

text:
Adult Occupant:
Pedestrian:

text: Smart electric drive[edit]

text: An all-electric version of the Fortwo, the Smart Fortwo electric drive, began development in 2006.[37][38] Field testing began in London with 100 units in 2007, and the second generation, with a total of 2,000 units, was introduced in 2009 and available in 18 markets around the world for leasing or through the Car2Go carsharing service in San Diego and Amsterdam.[14][15][39][40] Production of the second-generation Smart Fortwo electric drive began in November 2009 in Hambach, France. The Smart EDs have a lithium-ion battery provided by Tesla Motors with capacity of 14 kilowatt-hours (50 MJ). The range of a fully charged battery is up to 135 kilometres (84 miles) under the New European Driving Cycle (NEDC) cycle.[41][42] The U.S. Environmental Protection Agency's official all-electric range is 63 miles (101 km) and rated the Smart ED with a combined fuel economy of 87 miles per gallon gasoline equivalent (mpg-e) (2.7 L gasoline equivalent/100 km; 104 mpg-imp gasoline equivalent).[43]

text: The third-generation Smart electric drive is scheduled to be launched in the U.S. and Europe by the second quarter of 2013 and Daimler AG plans to mass-produce the electric car with availability in 30 markets worldwide.[15][44] The third-generation Smart electric drive was unveiled at the September 2011 Frankfurt Motor Show.[45] Key differences with the second-generation model include a more powerful electric motor, which improves acceleration and top speed, a new lithium-ion battery pack that will allow to increase the range to 140 kilometres (87 mi), and an option for quick-charge will be available.[15][45]

text: Brabus[edit]

text: Brabus (styled BRABUS) is a sport package that include a sport exhaust with dual center tips, sport suspension, 16- front and 17-inch rear wheels, power steering and various Brabus visual cues. An originally planned turbocharged engine was not included.[46] The Brabus package is available in cabriolet or coupe body styles, the latter equipped with a panoramic roof (made of glass for the first generation and polycarbonate for the second), and available in metallic silver or deep black.

text: Gallery[edit]

text:
Cabrio

Interior

text: Third generation (Build series C453, A453, 2014–present)[edit]

text:
Smart Fortwo (W453)

Overview

Production
2014–present (Global) 2014-2017 (USA Gas)

Body and chassis

Body style
3-door hatchback
2-door cabriolet

Related

Smart Forfour
Renault Twingo

Powertrain

Engine

0.9 L turbo I3
1.0 L petrol I3
66 kW synchronous electric motor

Transmission
5-speed manual
twin clutch automated manual
single-speed

Dimensions

Wheelbase
1,873 mm (73.7 in)

Length
2,695 mm (106.1 in)

Width
1,663 mm (65.5 in)

Height
1,555 mm (61.2 in)

Kerb weight
880 kg (1,940 lb)

text: Designed under the direction of Kai Sieber with designer Michael Gebhardt, the third generation made its worldwide debut on July 16, 2014,[12] having been jointly developed with Renault. The third generation is available as the 3-door 2-seater (internally designated as the C453 build series)[5] and 5-door 4-seater (internally designated the W453 build series), marketed as the Fortwo and Forfour, respectively. Motor Trend reported prior to its introduction that the third generation was to share approximately 70% of its parts with the third generation Renault Twingo.

text: The third generation Fortwo is powered by either of two 3-cylinder engines; a 1.0-litre engine producing 71 bhp, and 67 lb ft of torque and a turbocharged 0.9-litre (898 cc) 89 bhp engine with 100 lb ft of torque. A lower-powered 59 bhp engine will follow later. All versions come with either a manual five-speed gearbox or ‘twinamic’ automatic dual clutch transmission instead of the previous 'Softouch' system.[47] During development, Daimler had consulted with Ford to learn about their Ecoboost 1.0-litre turbo-charged inline 3-cylinder engine, in turn sharing information about its own Euro6 stratified lean-burn gasoline engines.[48]

text: Prior to its debut, Smart CEO Annette Winkler reported the C453 would share its 2.69 metre length with the current W451 build series[49] as well as its trademark hemispherical steel safety cell, marketed as the Tridion cell.[50] The Fortwo continues to be assembled at Smartville, and the Forfour is manufactured alongside the Renault Twingo 3 in Novo Mesto, Slovenia.[51]

text: Smartville, where the W450 and W451 build series have been manufactured, underwent a 200 million euro upgrade beginning in mid-2013, in preparation for the C453 Fortwo.

text: Cabriolet (A453) (2016-present)[edit]

text: In 2015, Smart announced a cabriolet version of the Smart Fortwo at the 2015 Frankfurt Motor Show. The smart fortwo cabrio launched globally in 2016. Cabrio models received additional safety cell reinforcements to compensate for the roof openings, including torsional bulkheads beneath the car, a crossbar behind the passenger seats (sometimes referred to as a basket handle), and additional reinforcement of the A-pillars. smart claims the standard power soft top will open or close in 12 seconds, and can be operated at any speed. At market launch, 5 soft top colors were offered; black, red, grey, beige and brown. Grey, beige and brown tops were marketed as BRABUS tailor made soft tops.[52]

text: The smart fortwo cabrio features removable roof bars that stow into an integrated storage space in the fortwo's rear tailgate. When removed, these roof bars allow for a fully open-air driving experience. The fortwo's roof bars are not integrated into the safety structure of the car, and only house the guide rails for the soft top to close. [53]

text: smart EQ rebrand (2018-present)[edit]

text: smart announced in March 2018 that electric versions of the smart fortwo would be rebranded as the smart EQ fortwo. This change was to further align with the upcoming Mercedes-EQ brand in which all Mercedes-Benz produced electric vehicles would receive EQ branding. The rebranding occurred for global March 2018 production, or Model Year 2018.5 in the United States & Canada. Both the coupe and cabrio electric drive models lost the electric drive badges front and rear and received smart EQ fortwo badges in their place, and received updated graphics in the optional smart Media-System. [54]

text: Gallery[edit]

text:
Passion Coupe

Midnight Blue Fortwo Coupe

Interior

Rear view

Smart EQ Fortwo at Geneva International Motor Show 2018

Fortwo Cabrio Electric Drive (Now Smart EQ Fortwo Cabrio)

Smart fortwo cabrio Brabus

text: International markets[edit]

text: The smart was initially available only in left-hand-drive form, as the floorpan allowed only for a left-hand-drive version. Smart subsequently designed a floorpan for right-hand-drive models. The Fortwo is now marketed in 37 countries worldwide.

text: Australia: The Smart Fortwo was marketed through select Mercedes-Benz dealers in Australia from 2003 to 2015 in only the middle 'Pulse' range, and with the petrol engine. In 2007, the base price for the Fortwo coupé was A$19,900, and the Fortwo cabriolet was $22,900. Mercedes-Benz stopped selling the Smart brand in Australia in 2015 due to declining sales.[55]

text: Brazil[edit]

text: The smart fortwo was officialy marketed through select Mercedes-Benz dealers in Brazil only from 2009 to 2015 (exclusively in its second generation), only with petrol engines. It was offered with the "micro-hybrid drive" natural aspirated engine (mhd) in standard configuration with a special edition named "Brazilian Edition" which was offered only in yellow (in reference to Brazilian national soccer team) with a Brazilian flag sticker on both sides, and turbocharged versions named "standard" (no name), Tritop and Passion. The mhd were offered only in "coupé" configuration with no sunroof, and turbocharged versions were offered in both coupé (with sunroof) and cabrio variants.

text: A few units of the fortwo Brabus were also offered in Brazil in the year 2010.

text: In 2016, Mercedes-Benz decided to discontinue offer of the fortwo in Brazilian market, hence Brazilian customers never had the option of the 453.

text: There are also a few W450s in Brazil, although they weren´t officialy imported by Mercedes-Benz and have no official support.

text: China: In April 2008, Smart premiered at the 2008 Beijing Auto Show. In October 2008, the Smart "vending machine" road show had the first stop in Shenyang and began the Fortwo's pre-order period.

text: Japan: The Fortwo is the only non-Japanese car ever to fulfill the regulations for Kei cars.[citation needed] There is a Japan-only variant of the first generation Smart Fortwo, called the Smart K.

text: Canada[edit]

text: This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2014) (Learn how and when to remove this template message)

text: The smart fortwo was introduced in Canada in September 2004 and sold through Mercedes-Benz dealers. Only the turbo-diesel powerplant was offered for the 450 coupé and 450 convertible models because the fuel vapour recovery system for the gasoline powered car would have had to be redesigned to meet Transport Canada standards. Diesels do not require such a system because the fuel is not volatile, so the cdi was certified instead. Demand was initially heavy, with up to six-month waiting lists in major urban areas in the spring of 2005. 10,242 cdi cars were imported in model years 2005 and 2006.[citation needed][56] Two or three of these were used in Transport Canada crash testing.

text: Canada received three special versions of the 450 cdi: the grandstyle—only available in dark green with silver, and beige leather—of which 200 were imported in coupé and cabriolet forms, the BRABUS nightrun—equipped with BRABUS accessories at the Hambach factory, which only came as a black on black (with blue-grey leather) coupé, and 50 of those were delivered, and finally the BRABUS Tailor Made Canada 1 models, of which only four were produced, three red on red and one white on white, all with highest equipment levels and all BRABUS accessories, high quality dyed-through leather and Alcantara interiors. The white car is a cabriolet, as are two of the red ones. The sole Canada 1 coupé has a fixed glass roof.

text: In 2008, Canada received only the gasoline 451 model because the diesel version did not meet 2007 Canadian emission standards. The 451 fortwo carries a 1.0-litre engine that delivers up to 70 horsepower (52 kW) and a re-engineered automated-manual 5-speed transmission with a slightly larger body. This engine has been the sole powertrain for Canada since the 451 was introduced—even the BRABUS models only have 70 HP. The 451 has sold very well in Canada: over 12,600 were registered between the start of 2008 and the end of 2012. The lack of a diesel option has hindered 451 sales to some owners of the diesel 450s.

text: Canada received several special versions of the 451 as well: the limited 1, the limited 3, the highstyle, the greystyle, the edit10n BRABUS Tailor Made (ten coupés), one all orange "Ultimate" BRABUS Tailor Made, the sharpred, among others.

text: Smart Canada released ten 10th anniversary edition smart Fortwo cars in February 2009. Each car started life as a Canadian BRABUS model before being converted into 10th anniversary editions by BRABUS in Germany. All examples feature arctic grey metallic paint with brown and alcantara leather interiors and black BRABUS Monoblock 7 wheels. The cars carry a number plate on the dash to signify its production number out of ten.

text: Smart Canada also commissioned Busch Automodelle GmbH to produce 1:87 scale versions (with a black tridion), of which 10,000 were made.

text: United States[edit]

text: In June 2002, a Smart Fortwo was exhibited in the U.S. at the Museum of Modern Art (MoMA) affiliate P.S. 1 in Queens, New York.

text: In January 2005, DaimlerChrysler showed the smart brand at the North American International Auto Show in Detroit, Michigan. smart forfour, smart roadster, smart fortwo coupe and smart fortwo cabrio models were shown.[57]

text: In September 2006, Daimler AG announced that Smart USA, a division of Penske Auto Group[58] would officially distribute Smart in the United States and Puerto Rico. Subsequently, the second generation smart Fortwo (Model 451) became available in January 2008.

text: The 2009 model year US version of the smart Fortwo was available in three trims: Pure (base trim), Passion, and Passion cabriolet. Pure has an MSRP of US$11,990, Passion has an MSRP of $13,990, and the Passion Cabriolet has an MSRP $16,990.[59] A reservation program was launched by Smart USA in March 2007.[60][61] This program allowed interested parties to place a $99 refundable deposit on the new Fortwo in preparation for the product's launch. Since the product's launch, sales have surpassed production and the reservation program continues as a "wait list" program.[62][63] The average wait used to be 12 to 18 months for delivery; although due to the economy, many buyers couldn't purchase the vehicles when they were ready for delivery and many are available on dealer lots.[citation needed]

text: The Fortwo was rated as the most fuel efficient two-seater car in the United States Environmental Protection Agency's (EPA) 2008 Fuel Economy Guide, with fuel efficiency ratings of 33 mpg‑US (7.1 L/100 km; 40 mpg‑imp) city and 41 mpg‑US (5.7 L/100 km; 49 mpg‑imp) highway.[64] The 2008 Smart Fortwo coupe was given an EPA fuel efficiency rating of 36 mpg‑US (6.5 L/100 km; 43 mpg‑imp) combined.[65]

text: On May 14, 2008, the Insurance Institute for Highway Safety released crash test results for the Fortwo. The IIHS gave the Fortwo top ratings in protecting passengers in front and side crashes.[66] However, the U.S. National Highway Traffic Safety Administration (NHTSA) cited a Safety Concern on their tests of a 2008 Fortwo, stating "during the side impact test, the driver door unlatched and opened. A door opening during a side impact crash increases the likelihood of occupant ejection."[67]

text: For model years 2012 and later, the U.S. Fortwo Coupe featured eight airbags (front, knee, side and window curtain), while the Cabrio model featured six airbags (front, knee and side-mounted combination head/thorax).

text: In early 2006, prior to formal importation to the United States, a specialty firm—G and K Auto conversions of Santa Ana California received DOT, NHTSA, and EPA approval to market a modified European specification Smart Fortwo in the US. Modifications for the grey market vehicles included DOT certified headlights, front and rear side marker lights, reinforced doors for additional side impact protection, an odometer in miles rather than kilometres, and soft padding on the interior pillars and ceiling. Approximately 1,000 model year 2004, 2005, and 2006 cars were imported.

text: In September 2015, the third generation smart fortwo coupe (C453) launched in the United States for the 2016 model year. US variants are offered in four trim levels; pure, passion, prime and proxy. Significant upgrades, including power steering, eight airbags, alarm, Bluetooth capability and crosswind assist technology were made standard. The 2016 smart fortwo also received a new engine, the 0.9 liter 3-cylinder turbocharged unit making 89 horsepower and 100 pound-feet of torque as standard. Both a 5-speed manual transmission and a 6-speed dual-clutch automatic transmission are offered.[68]

text: In August 2016, the redesigned 2017 smart fortwo cabrio (A453) joined the smart USA lineup, offered in three trim levels; passion, prime and proxy. The cabrio model makes use of the same gasoline engine and transmissions as the C453 fortwo coupe.[69] A BRABUS Sport Package was also added for 2017 for fortwo coupe and cabrio models, adding unique front and rear body styling, wheels, interior appointments and a retuned sport suspension.[70]

text: The 4th generation smart fortwo electric drive made its debut at the 2016 Paris Motor Show.[71] The newest generation, built on the C453 chassis, features a new 17.6 kWh lithium-ion battery and an air-cooled electric motor which produce 81 horsepower and 118 lb.-ft. of torque. A new 7.2 kW onboard charger was added, and smart advertised a charging time of 2.5 hours at a 240V electrical outlet. EPA estimated range was 58 miles, and the vehicle was rated at 124 MPGe City, making it the most efficient 2 seat vehicle on sale in the USA.[72] The 2017 smart fortwo electric drive is offered in both coupe and cabrio versions in all 50 states, and qualifies for a $7,500 federal tax incentive.[73]

text: In February 2017, smart USA announced the brand would discontinue gasoline vehicle sales after the 2017 model year and focus purely on battery electric vehicles.[74] The smart fortwo electric drive arrived as a 2017 model in the summer of 2017, and the transition to electric-only occurred for the 2018 model year.[75]

text: The year 2018 marked 10 years of smart fortwo sales in the United States, and the brand offered a special 10th anniversary edition specific to the United States market to celebrate. The edition was available for passion and prime lines of the fortwo coupe, and consisted of:

text:
Exclusive Sapphire Blue Metallic body panels, mirror caps, tridion cell, and grille
16-Inch BRABUS Monoblock VII Wheels in Matte Anthracite Grey
Sport Package
BRABUS-created edition exterior badging in place of the line badge
Custom-stitched '10th anniversary' BRABUS floor mats
10th anniversary BRABUS shift knob[76]

text: Chinese copy controversy[edit]

text: In 2007, Chinese manufacturer Shijiazhuang Shuanghuan Automobile Co released the Shuanghuan Noble (also known as the Martin Motors Bubble), designed similarly to the Fortwo and prompting Daimler AG to sue Shuanghuan for copyright infringement.[77] The German manufacturer persuaded the Italian court to prohibit the Noble from being exhibited at the Bologna Motor Show, but importer Martin Motors violated that injunction and put the car on display.[78]

text: In May 2009, a Greek judge ruled against Daimler, allowing the Noble to be sold in Greece. The judge cited that "if a vehicle varies in its technical specification, then any external similarities are irrelevant." This was in reference to the Noble being a front-engine, front-wheel-drive car, while the Fortwo is a similar sized rear-engine and rear-wheel-drive car.[79]


document_title: The Joey Bishop Show (sitcom)

question_text: who played the wife on the joey bishop show

text: The Joey Bishop Show (sitcom)

text: Overview[edit]

text: Season one[edit]

text: The series was conceived as a vehicle for Joey Bishop by Danny Thomas and Louis F. Edelman in 1960. At the time, Thomas was starring in his own series, Make Room for Daddy (later known as The Danny Thomas Show), airing on CBS. Thomas' series was then a top-20 hit and served as a launching pad for The Joey Bishop Show.[1] The series' pilot episode, entitled "Everything Happens to Me", aired on March 27, 1961, during the eighth season of Danny Thomas.[2] In the pilot, an incompetent Hollywood "public relations man" named Joey Mason (Bishop) forgets to make proper accommodations for an exhausted Danny Williams (Thomas) after he arrives in Los Angeles to play a show. Joey is then forced to put Danny up in the home he shares with his colorful parents, Mr. and Mrs. Mason (played by Billy Gilbert and Madge Blake) and two unmarried sisters, Betty (Virginia Vincent) and aspiring actress Stella (Marlo Thomas).[3][4]

text: By the time the series was picked up by NBC, Bishop's character's name was changed to Joey Barnes (Bishop had insisted his character and he share the same initials)[5] and the character of Joey's father was dropped. Two additional characters were added; a younger brother named Larry, and Frank, the husband of Joey's older sister Betty. The series' first incarnation features Joey, a well-intending but hapless and trouble-prone young man, who works for the Hollywood public relations firm, Willoughby, Cleary and Jones. The firm is headed by J.P. Willoughby (John Griggs), Joey's demanding boss. Willoughby's secretary, Barbara Simpson (Nancy Hadley), is Joey's girlfriend. Joey lives with and supports his widowed mother, Mrs. Barnes (Madge Blake), younger sister Stella (Marlo Thomas) and younger brother Larry (Warren Berlinger), who is a medical student. Joey also supports his older sister Betty (Virginia Vincent) and her proudly unemployed husband Frank (Joe Flynn).[2]

text: The storylines during the first season typically revolve around Joey's misadventures concerning his job. Problems also arise when family members, who often think he has more influence in Hollywood than he actually has, attempt to take advantage of his nonexistent influence.[6] As the series was a spin-off of The Danny Thomas Show, Danny Thomas and Marjorie Lord appeared as their Danny Thomas characters in the first season's fourth episode entitled "This Is Your Life". Sid Melton, who appeared as Uncle Charley Halper on Danny Thomas, also appeared.

text: After its September 1961 premiere, the series struggled in the ratings. In an effort to improve viewership, NBC decided to "readjust" the series in the second season, beginning with several characters dropped (Joey's mother, sister Stella, brother Larry, brother-in-law Frank, and girlfriend Barbara Simpson. Several crew members were also dismissed), and a new context for the series in which Joey becomes a TV personality. The changes helped the series' ratings in the second season.[7]

text: Seasons two through four[edit]

text: After the first season, Bishop decided to fully change the format of the series.[8] In addition to the format changing, The Joey Bishop Show began filming in front of a live audience and also featured an entirely different supporting cast. In the second incarnation, Joey Barnes is the host of a New York City talk/variety television show. Abby Dalton joined the cast as Joey's new wife Ellie (whom Joey called "Texas" because she hailed from Texas) and the two live at the Carlton Arms, a posh Manhattan apartment building. Towards the end of season two, Ellie discovers she is pregnant with the couple's first child. Their son, Joey Barnes, Jr. (played by Dalton's real son Matthew David Smith), was born in the season-two finale "The Baby Cometh". Also joining the cast was Guy Marks, who portrayed Freddie, Joey's manager. Marks left the series after 19 episodes and Corbett Monica joined the cast as Larry Corbett, Joey's head writer. The supporting cast also includes Mary Treen as Hilda, the Barnes' maid and baby nurse, with whom Joey frequently trades insults. Joe Besser portrayed Mr. Jillson, the building's henpecked super who lives in fear of his wife, Tantalia (who is never seen but often heard).[2]

text: Storylines for the remainder of the series' run mainly focus on Joey's home life, but also feature storylines involving Joey's job as a television host. As such, various celebrities (who typically appeared as themselves) who were guests on Joey Barnes' talk show appeared throughout the series' run. Although the second incarnation of the series was seemingly unrelated to the first incarnation, the series featured Danny Thomas in two season-three episodes: "Danny Gives Joey Advice" and "Andy Williams Visits Joey".

text: One notable feature of the series was a considerable amount of ad-libbing and breaking up, and—unusually for a filmed sitcom—much of it was left in. (In "Jillson and the Cinnamon Buns", Besser actually apologizes to Bishop for making him laugh with an off-the-cuff joke.) Because of this, the series' studio audiences were audibly more responsive than those of other multi-camera comedies of the era.

text: Episodes[edit]

text: Cast[edit]

text:
Joey Bishop as Joey Barnes
Abby Dalton as Ellie Barnes (1962–1965)
Madge Blake as Mrs. Barnes (1961–1962)
Warren Berlinger as Larry Barnes (1961–1962)
Joe Flynn as Frank (1961–1962)
John Griggs as J.P. Willoughby (1961)
Nancy Hadley as Barbara Simpson (1961–1962)
Virginia Vincent as Betty (1961–1962)
Marlo Thomas as Stella Barnes (1961–1962)
Joe Besser as Mr. Jillson (1962–1965)
Bill Bixby as Charles Raymond (1962)
Guy Marks as Freddie (1962)
Corbett Monica as Larry Corbett (1963–1965)
Mary Treen as Hilda (1962–1965)
Joey Forman as Dr. Sam Nolan (1964–1965)

text: Guest stars[edit]

text: The Joey Bishop Show featured several celebrity guest stars who appeared as themselves. Among the celebrity guest stars are:

text:
The Andrews Sisters
Edgar Bergen
Milton Berle
Jack Carter
Vic Damone
Tommy Davis
Willie Davis
Don Drysdale
Zsa Zsa Gabor
Shecky Greene
Robert Goulet
Buddy Hackett
Frank Howard
Jack Jones
Don Knotts
Jack E. Leonard
Oscar Levant
Jerry Lewis
Claudine Longet
Ed McMahon
Jan Murray
Jack Paar
Bobby Rydell
Roberta Sherwood
Bill "Moose" Skowron
Danny Thomas
Andy Williams

text: Actors who appeared in guest starring roles include:

text:
Jack Albertson
Merry Anders
Cliff Arquette
Parley Baer
Raymond Bailey
Neville Brand
Frank Cady
Jean Carson
Jackie Coogan
Ellen Corby
Henry Gibson
Rusty Hamer
Sterling Holloway
Nancy Kulp
Sue Ane Langdon
Joi Lansing
George Lindsey
Howard McNear
Jaye P. Morgan
Burt Mustin
Maidie Norman
Dennis O'Keefe
Barbara Stanwyck
George Tobias
Lee Van Cleef
Dawn Wells

text: Reception[edit]

text: Upon its premiere, The Joey Bishop Show struggled in the ratings. After the first re-tooling, ratings for the series improved and NBC renewed it for another season. The series' second revamped season proved to be popular with audiences and ratings increased. By the end of the third season, the series had dropped in the ratings again and NBC announced it would be dropped from its lineup in January 1964 (the series' third-season finale episode aired in May 1964).[9]

text: Also at this time, despite its high ratings, Danny Thomas decided to end his series The Danny Thomas Show after 11 years. To compensate for Thomas's absence, CBS immediately picked up The Joey Bishop Show for the 1964–65 television season. A few changes were made. When it made its debut on NBC in 1961, The Joey Bishop Show was telecast in black-and-white. The third episode from the first season, "A Windfall For Mom", was shot and broadcast in color. The series switched to color for the second and third seasons. After it moved to CBS for the 1964-65 season, it reverted to black-and-white.[2] Also, juvenile actor Rusty Hamer, who was a regular on The Danny Thomas Show, was featured in three installments of The Joey Bishop Show as his character Rusty Williams - "Rusty Arrives", "Rusty's Education", and "Joey Entertains Rusty's Fraternity".[10] The Season 4 debut episode, "Joey Goes to CBS", premiered on Sunday night September 27, 1964 at 9:30 P.M. on CBS. It followed the short-lived sitcom My Living Doll starring Robert Cummings and Julie Newmar which aired at 9:00 P.M. Both programs, like the previous year's The Judy Garland Show, had the unenviable position of being pitted against NBC's highly popular western series Bonanza. As a result, ratings for both My Living Doll and The Joey Bishop Show were low. By the late fall of 1964, the programs were clearly in trouble.

text: In a last ditch effort to save the shows, in late December, 1964, CBS moved My Living Doll to Wednesday nights and The Joey Bishop Show to Tuesday nights. The ratings for both shows did not improve and CBS canceled both series in March, 1965.[11]

text: Production notes[edit]

text: The series was created by Louis F. Edelman and Danny Thomas who also served as the executive producer. The series was produced by Thomas' company, Bellmar Enterprises.[12] It was filmed at Desilu Studios in front of a live studio audience, with a laugh track added during post-production for "sweetening" purposes.[13]

text: Lost episode[edit]

text: One Season 3 episode of The Joey Bishop Show is now considered lost. The episode, known only as #85, was filmed on November 15, 1963 and guest starred comedian and impressionist Vaughn Meader. Meader rose to fame in the early 1960s for his impersonation of then-President John F. Kennedy featured on the popular comedy album The First Family. The episode centered around Meader performing his Kennedy impersonation in routines opposite Joey Bishop. A week after filming, President Kennedy was assassinated in Dallas. President Kennedy's death promptly ended Meader's career – his club bookings and television appearances were quickly canceled and his albums were pulled from stores. The episode featuring Meader was scheduled to air in February 1964, but was pulled by NBC.[14] The episode never aired and was reportedly destroyed.[15][16]

text: Syndication[edit]

text: Episodes of The Joey Bishop Show aired on TV Land in 1998.[17] In 2016, the series began airing on Retro TV.

text: Antenna TV announced in October 2016 it would begin airing the series the following January, including the rarely seen first season.[18]

text: Home media[edit]

text: In September 2004, Questar Entertainment released the complete second season of The Joey Bishop Show on Region 1 DVD in the United States.[19]

text: On March 13, 2018, SFM Entertainment (distributed by Allied Vaughn) released all four seasons plus a "Complete Series" set on DVD in Region 1 via Amazon.com's CreateSpace program. These are Manufacture-on-Demand (MOD) releases, available exclusively through Amazon.com.[20]


question_text: the foxp2 sequences of mice were most different from those of

text: Discovery[edit]

text: FOXP2 and its gene were discovered as a result of investigations on an English family known as the KE family, half of whom (fifteen individuals across three generations) suffered from a speech and language disorder called developmental verbal dyspraxia. Their case was studied at the Institute of Child Health of University London College.[20] In 1990 Myrna Gopnik, Professor of Linguistics at McGill University, reported that the disorder-affected KE family had severe speech impediment with incomprehensible talk, largely characterized by grammatical deficits.[21] She hypothesized that the basis was not of learning or cognitive disability, but due to genetic factors affecting mainly grammatical ability.[22] (Her hypothesis led to a popularised existence of "grammar gene" and a controversial notion of grammar-specific disorder.[23][24]) In 1995, the University of Oxford and the Institute of Child Health researchers found that the disorder was purely genetic.[25] Remarkably, the inheritance of the disorder from one generation to the next was consistent with autosomal dominant inheritance, i.e., mutation of only a single gene on an autosome (non-sex chromosome) acting in a dominant fashion. This is one of the few known examples of Mendelian (monogenic) inheritance for a disorder affecting speech and language skills, which typically have a complex basis involving multiple genetic risk factors.[26]

text: In 1998, Oxford University geneticists Simon Fisher, Anthony Monaco, Cecilia S. L. Lai, Jane A. Hurst, and Faraneh Vargha-Khadem identified an autosomal dominant monogenic inheritance that is localized on a small region of chromosome 7 from DNA samples taken from the affected and unaffected members.[5] The chromosomal region (locus) contained 70 genes.[27] The locus was given the official name "SPCH1" (for speech-and-language-disorder-1) by the Human Genome Nomenclature committee. Mapping and sequencing of the chromosomal region was performed with the aid of bacterial artificial chromosome clones.[6] Around this time, the researchers identified an individual who was unrelated to the KE family, but had a similar type of speech and language disorder. In this case the child, known as CS, carried a chromosomal rearrangement (a translocation) in which part of chromosome 7 had become exchanged with part of chromosome 5. The site of breakage of chromosome 7 was located within the SPCH1 region.[6]

text: In 2001, the team identified in CS that the mutation is in the middle of a protein-coding gene.[3] Using a combination of bioinformatics and RNA analyses, they discovered that the gene codes for a novel protein belonging to the forkhead-box (FOX) group of transcription factors. As such, it was assigned with the official name of FOXP2. When the researchers sequenced the FOXP2 gene in the KE family, they found a heterozygous point mutation shared by all the affected individuals, but not in unaffected members of the family and other people.[3] This mutation is due to an amino-acid substitution that inhibits the DNA-binding domain of the FOXP2 protein.[28] Further screening of the gene identified multiple additional cases of FOXP2 disruption, including different point mutations[9] and chromosomal rearrangements,[29] providing evidence that damage to one copy of this gene is sufficient to derail speech and language development.

text: Function[edit]

text: FOXP2 is required for proper brain and lung development. Knockout mice with only one functional copy of the FOXP2 gene have significantly reduced vocalizations as pups.[30] Knockout mice with no functional copies of FOXP2 are runted, display abnormalities in brain regions such as the Purkinje layer, and die an average of 21 days after birth from inadequate lung development.[13]

text: FOXP2 is expressed in many areas of the brain[17] including the basal ganglia and inferior frontal cortex where it is essential for brain maturation and speech and language development.[15]

text: A knockout mouse model has been used to examine FOXP2's role in brain development and how mutations in the two copies of FOXP2 affect vocalization. Mutations in one copy result in reduced speech while abnormalities in both copies cause major brain and lung developmental issues.[13]

text: The expression of FOXP2 is subject to post-transcriptional regulation, particularly micro RNA, which binds to multiple miRNA binding-sites in the neocortex, causing the repression of FOXP2 3’UTR.[31]

text: Clinical significance[edit]

text: There are several abnormalities linked to FOXP2. The most common mutation results in severe speech impairment known as developmental verbal dyspraxia (DVD) which is caused by a translocation in the 7q31.2 region [t(5;7)(q22;q31.2)].[3][6] A missense mutation causing an arginine-to-histidine substitution (R553H) in the DNA-binding domain is thought to be the abnormality in KE.[32] A heterozygous nonsense mutation, R328X variant, produces a truncated protein involved in speech and language difficulties in one KE individual and two of their close family members.[9] R553H and R328X mutations also affected nuclear localization, DNA-binding, and the transactivation (increased gene expression) properties of FOXP2.[33][34] Although DVD associated with FOXP2 disruptions are thought to be rare (~2% by one estimate),[9] a faulty copy of FOXP2 in individuals always causes speech and language problems.

text: Several cases of developmental verbal dyspraxia in humans have been linked to mutations in the FOXP2 gene.[29][35][36][37] Such individuals have little or no cognitive handicaps but are unable to correctly perform the coordinated movements required for speech. fMRI analysis of these individuals performing silent verb generation and spoken word repetition tasks showed underactivation of Broca's area and the putamen, brain centers thought to be involved in language tasks. Because of this, FOXP2 has been dubbed the "language gene". People with this mutation also experience symptoms not related to language (not surprisingly, as FOXP2 is known to affect development in other parts of the body as well).[38] Scientists have also looked for associations between FOXP2 and autism, and both positive and negative findings have been reported.[39][40]

text: There is some evidence that the linguistic impairments associated with a mutation of the FOXP2 gene are not simply the result of a fundamental deficit in motor control. For examples, the impairments include difficulties in comprehension. Brain imaging of affected individuals indicates functional abnormalities in language-related cortical and basal/ganglia regions, demonstrating that the problems extend beyond the motor system.

text: Evolution[edit]

text: The FOXP2 gene is highly conserved in mammals.[41] Human gene differs from non-human primates by the substitution of two amino acids, threonine to asparagine substitution at position 303 (T303N) and asparagine to serine substitution at position 325 (N325S).[32] In mice it differs from that of humans by three substitutions, and in zebra finch by seven amino acids.[17][42][43] One of the two amino acid difference between human and chimps also arose independently in carnivores and bats.[13][44] Similar FOXP2 proteins can be found in songbirds, fish, and reptiles such as alligators.[45][46]

text: DNA sampling from Homo neanderthalensis bones indicates that their FOXP2 gene is a little different, though largely similar to those of Homo sapiens (i.e. humans).[47][48]

text: The FOXP2 gene showed indications of recent positive selection.[41][49] Some researchers have speculated that positive selection is crucial for the evolution of language in humans.[17] Others, however, have been unable to find a clear association between species with learned vocalizations and similar mutations in FOXP2.[45][46] Insertion of both human mutations into mice, whose version of FOXP2 otherwise differs from the human and chimpanzee versions in only one additional base pair, causes changes in vocalizations as well as other behavioral changes, such as a reduction in exploratory tendencies. A reduction in dopamine levels and changes in the morphology of certain nerve cells are also observed.[18]

text: However, FOXP2 is extremely diverse in echolocating bats.[50] Twenty-two sequences of non-bat eutherian mammals revealed a total number of 20 nonsynonymous mutations in contrast to half that number of bat sequences, which showed 44 nonsynonymous mutations.[44] Interestingly, all cetaceans share three amino acid substitutions, but no differences were found between echolocating toothed whales and non-echolocating baleen cetaceans.[44] Within bats, however, amino acid variation correlated with different echolocating types.[44]

text: Interactions[edit]

text: FOXP2 interacts with a regulatory gene CTBP1.[51] It also downregulates CNTNAP2 gene, a member of the neurexin family found in neurons. The target gene is associated with common forms of language impairment.[52] It regulates the repeat-containing protein X-linked 2 (SRPX2), which is an epilepsy and language-associated gene in humans, and sound-controlling gene in mice.[53]

text: Mice[edit]

text: In a mouse FOXP2 knockout study, loss of both copies of the gene caused severe motor impairment related to cerebellar abnormalities and lack of ultrasonic vocalisations normally elicited when pups are removed from their mothers.[30] These vocalizations have important communicative roles in mother-offspring interactions. Loss of one copy was associated with impairment of ultrasonic vocalisations and a modest developmental delay. Male mice on encountering female mice produce complex ultrasonic vocalisations that have characteristics of song.[54] Mice that have the R552H point mutation carried by the KE family show cerebellar reduction and abnormal synaptic plasticity in striatal and cerebellar circuits.[10]

text: Birds[edit]

text: In songbirds, FOXP2 most likely regulates genes involved in neuroplasticity.[11][55] Gene knockdown of FOXP2 in Area X of the basal ganglia in songbirds results in incomplete and inaccurate song imitation.[11] Overexpression of FoxP2 was accomplished through injection of adeno-associated virus serotype 1 (AAV1) into Area X of the brain. This overexpression produced similar effects to that of knockdown; juvenile zebra finch birds were unable to accurately imitate their tutors.[56] Similarly, in adult canaries higher FOXP2 levels also correlate with song changes.[43]

text: Levels of FOXP2 in adult zebra finches are significantly higher when males direct their song to females than when they sing song in other contexts.[55] “Directed” singing refers to when a male is singing to a female usually for a courtship display. “Undirected” singing occurs when for example, a male sings when other males are present or is alone.[57] Studies have found that FoxP2 levels vary depending on the social context. When the birds were singing undirected song, there was a decrease in of FoxP2 expression in Area X. This downregulation was not observed and FoxP2 levels remained stable in birds singing directed song.[58]

text: Differences between song-learning and non-song-learning birds have been shown to be caused by differences in FOXP2 gene expression, rather than differences in the amino acid sequence of the FOXP2 protein.

text: FOXP2 also has possible implications in the development of bat echolocation.[32][44][59]