I'm just stumped about Chromosome #2.

I understand about the fused chromosome but what I can't understand is the timeframe involved.

Our common ancestor could not have given birth to a child with 46 chromosomes. For one, it would not have survived and even if it did, it would not have been able to procreate.

At some point though, 48 had to become 46. If this is done over a period of time, how was this able to happen without lethal consequences to the species?

Thank you for your time.

see
http://www.askabiologist.org.uk/answers … hp?id=1048