You raise an interesting topic I've never really given much thought to (time vs generations). Makes me think of other questions about genetics that I just don't know the answers to but that someone must have thought of.

Things like: How do they account for recessive traits? Can something that is recessive become dominant? Can something dominant just disappear (I imagine that it could with mutations happening so much)? Is there a specific animal they use to test these things? Do different traits take longer to evolve towards?

I imagine they use something that reproduces rapidly (fruit flies? fleas?).

On the topic of this spider and how does it know what it looks like...I don't know how much brainpower the spiders have but I know that we have a part of the brain that tracks where our body is (at least in relation to other body parts). Is it possible the spiders have something similar? Can this even be used to make a rough representation of oneself?

I am going to have to google some of these later as I'm now curious.