Philip M I needed to check on chromosome counts before commenting, so I looked for 'chromosome horse donkey mule'. I chose the second hit -- Wiki again! Quite a lot of good info here though I didn't cross check the results. Interesting point -- Man has 46 chromosomes, horses 64, donkies 62, mules 63. Back when I thought that Man at the top of the evolutionary tree must have the highest chromosome count, I found a reference to a fern which, from memory, had 512. Very sobering. Again from Wiki, http://en.wikipedia.org/wiki/Chimpanzee_genome_project we learn that the apes have 48 chromosomes and it appears that human chromosome 2 is the fused chromosomes in chimps labelled as 2a and 2b. This little snippet caught my attention - Results from the human and chimp genome analyses should help in understanding some human diseases. Humans appear to have lost a functional caspase-12 gene, which in other primates codes for an enzyme that may protect against Alzheimer's disease. Paul D Sick of deleting your inbox? Yahoo!7 Mail has free unlimited storage. http://au.docs.yahoo.com/mail/unlimitedstorage.html