Among the apes, the gibbon is the farthest from humans. Michael Bedford discovered that human sperm could penetrate the protective outer membranes of a gibbon egg. The next year he fell under political criticism from the Soviet government and was sentenced to exile in the Kazakh SSR during the Great Purge he died two years later (see below).Īs far back as 1977, researcher J. In 1929 he organized a set of experiments involving ape sperm and human volunteers, but was delayed by the death of his last orangutan. At first working with human sperm and chimpanzee females, none of his attempts created a pregnancy.
In the 1920s the Soviet biologist Ilya Ivanovich Ivanov carried out a series of experiments to create a human/ape hybrid. caballus) with 32 chromosome pairs, have been found to be interfertile, and produce semi-fertile offspring, where male hybrids can breed with female domestic horses. In a direct parallel to the chimp-human case, the Przewalski horse (Equus przewalskii) with 33 chromosome pairs, and the domestic horse (E. Similar complexities and prevalent sterility pertain to horse-zebra hybrids, or zorses, whose chromosomal disparity is very wide, with horses typically having 32 chromosomes and zebras possessing between 44 and 62 depending upon species.
Interfertility of horses and donkeys is common, although sterility of the offspring ( mules) is nearly universal. This level of chromosomal similarity is roughly equivalent to that found in equines. Some older references will include Y as a match between gorillas, chimps, and humans, but chimpanzees (including bonobos) and humans have recently been found to share a large transposition from chromosome 1 to Y that is not found in any other ape. Chimps and humans match on 1, 2p, 2q, 5, 7 - 10, 12, 16, and Y as well. 3, 11, 14, 15, 18, and 20 match between gorillas, chimpanzees, and humans. Chromosomes 6, 13, 19, 21, 22, and X are structurally the same in all great apes. The genetic structure of all the great apes, including humans, is similar. Similar mismatches are relatively common in existing species, a phenomenon known as chromosomal polymorphism. Having different numbers of chromosomes is not an absolute barrier to hybridization. Humans have one chromosome fewer than other apes, since the ape chromosomes 2p and 2q have fused into a large chromosome (which contains remnants of the centromere and telomeres of the ancestral 2p and 2q) in humans. For geneticists, "Chuman" therefore refers to a hybrid of male chimpanzee and female human, while "Humanzee" or "manpanzee" refers to a hybrid of male human and female chimpanzee. Hybrids are named according to the convention first part of sire's name + second part of dam's name (except where the result is unwieldy). tigon/liger) This is important because of the phenomenon of genomic imprinting where genes are expressed differently depending on which parent contributed them. Geneticists adhere to the portmanteau word convention to indicate which species is the sire.
In spite of the usual convention of portmanteau words to describe hybrids, there is no consensus as to which word to use, though "chuman" or "humanzee" are used in popular speech.