2 questions

[NAME MICHAEL ALLEN]

I have two questions:

Is homo sapiens the most recently evolved large animal?  By large,
I mean larger than a mouse.  Insects don't count.

Do all male animals have a Y chromosome that is much smaller than the X
chromosome or is this characteristic limited to a particular group like
mammals or primates?

Thanks

Michael Allen		mjallen at ac.dal.ca
Dalhousie University
Halifax, Nova Scotia
Canada