More and better data are steadily being accumulated, and in 2013 a review of ape DNA based on the genomes of 79 great apes was published. Shutterstock/Sergey Uryadnikov/Petr Masek/Sergey Uryadnikov/Eric Gevaert How close? A chimpanzee (top left), an orangutan (top right), a gorilla (bottom left) and a bonobo (bottom right). Over the past decade researchers have published good draft sequences of the nuclear genomes of the chimpanzee, orangutan, gorilla and the bonobo. Nowadays technological advances mean that whole genomes can be sequenced. The discovery by James Watson and Francis Crick, with unwitting help from Rosalind Franklin, of the basic structure of DNA, and the subsequent discovery by Crick and others of the nature of the genetic code, meant that the relationships among organisms could be pursued at the level of the genome. In 1975 the American human geneticist Mary-Claire King and Allan Wilson showed that 99% of the amino-acid sequences of chimpanzee and modern human blood proteins were identical. This date was less than half of contemporary estimates based on fossil evidence. They also provided the first molecular clock estimate of modern human-African ape divergence, dating the split to only around five million years ago. In the late 1960s, the American anthropologist Vince Sarich and New Zealand biologist Allan Wilson exploited these minor differences in protein structure and concluded that modern humans and the African apes were very closely related. Proteins are made up of a string of amino acids and in many instances one amino acid can be substituted for another without changing the function of the protein. He concluded that this was because the albumin molecules were, to all intents and purposes, identical. He showed that the patterns produced by the albumins of modern humans and the chimpanzee were identical. Goodman used a different method, immunodiffusion, to study albumin, a serum protein. He showed that the patterns of the peptides from modern humans, gorilla and chimpanzee were indistinguishable.

Zuckerkandl used enzymes to break up the protein component of haemoglobin into its peptide components. The results of applying a new generation of analytical methods to proteins were reported by the Austrian-born French biologist Emile Zuckerkandl and American biologist Morris Goodman in the early 1960s. A closer inspectionĭevelopments in biochemistry and immunology during the first half of the 20th century enabled the search for evidence of the relationships between modern humans and the apes to shift from macroscopic morphology to the morphology of molecules.

He speculated that because African apes were morphologically closer to modern humans than the apes from Asia, then the ancestors of modern humans were more likely to be found in Africa than elsewhere. This was the evidence the English naturalist Charles Darwin referred to in The Descent of Man in 1871. In the central section of a small book he published in 1863, called Evidence as to Man’s Place in Nature, Huxley concluded that the differences between modern humans and African apes were less than those between African apes and orangutans. The first person to undertake a systematic comparative review of these differences between modern humans and the apes was English biologist Thomas Henry Huxley. Biologist Thomas Henry Huxley (1825-1895).

Origin usa