Of course, thats about all they will ever be able to study in detail, so they have to fill in some blanks...leaves them open to criticism.
Actually, I'm facinated by DNA/Genetic analysis....Google Haplogroup sometime. Talks about y Chromosome mutations which likely occurs once every few thousand years or so.
There IS a "THEORY OF EVOLUTION"....which may or may not be true.(I'm kinda skeptical...but open).
It is NOT a proven fact....and never can be with our current ability (or perhaps lack of) to replicate. (REMEMBER....in science...unless you can REPLICATE in a lab...it's just a THEORY).
redrock