Robertsonian fusion of ape chromosomes in Homo
Humans
have 2n=46
chromosomes, as compared with 2n=48 in all of our other closest relatives,
the Great Apes (Chimpanzee, Gorillas, and Orangutans).
Whereas Chromosome 2
is a single, large
sub-metacentric in humans, the other apes have two smaller, acrocentric
chromosomes. Comparison of banding patterns allows these
chromosomes to be aligned, and shows that during human
evolution the ancestral chromosomes have undergone an end-to-end Robertsonian fusion to form
a single larger chromosome. The gene contents of chimp and
human chromosomes are substantially identical [note that the
bands are conserved]. Molecular inspection of the area in
the human 2q1.2~1.4 region shows telomere-like
DNA sequences from the chimp chromosomes,
as predicted.