http://en.wikipedia.org/wiki/Evidence_of_common_descent#Chromosome_2_in_humans
Main article: Chromosome 2 (human)
Further information: Genes of the Chromosome 2 fusion site in chimpanzees
Fusion of ancestral chromosomes left distinctive remnants of telomeres, and a vestigial centromere
Evidence for the evolution of Homo sapiens from a common ancestor with chimpanzees is found in the number of chromosomes in humans as compared to all other members of Hominidae. All hominidae have 24 pairs of chromosomes, except humans, who have only 23 pairs. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[20][21]
The evidence for this includes:
The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the common chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[22][23]
The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere.[24]
The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the middle.[25]
Chromosome 2 thus presents very strong evidence in favour of the common descent of humans and other apes. According to J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2."[25]
Main article: Chromosome 2 (human)
Further information: Genes of the Chromosome 2 fusion site in chimpanzees
Fusion of ancestral chromosomes left distinctive remnants of telomeres, and a vestigial centromere
Evidence for the evolution of Homo sapiens from a common ancestor with chimpanzees is found in the number of chromosomes in humans as compared to all other members of Hominidae. All hominidae have 24 pairs of chromosomes, except humans, who have only 23 pairs. Human chromosome 2 is a result of an end-to-end fusion of two ancestral chromosomes.[20][21]
The evidence for this includes:
The correspondence of chromosome 2 to two ape chromosomes. The closest human relative, the common chimpanzee, has near-identical DNA sequences to human chromosome 2, but they are found in two separate chromosomes. The same is true of the more distant gorilla and orangutan.[22][23]
The presence of a vestigial centromere. Normally a chromosome has just one centromere, but in chromosome 2 there are remnants of a second centromere.[24]
The presence of vestigial telomeres. These are normally found only at the ends of a chromosome, but in chromosome 2 there are additional telomere sequences in the middle.[25]
Chromosome 2 thus presents very strong evidence in favour of the common descent of humans and other apes. According to J. W. IJdo, "We conclude that the locus cloned in cosmids c8.1 and c29B is the relic of an ancient telomere-telomere fusion and marks the point at which two ancestral ape chromosomes fused to give rise to human chromosome 2."[25]
