Perhaps there's already another way to do this? What I'd like to do is see the traits of a parent and its child, specifically what the differences are. That way, tracing down the tree I can see what traits were advantageous, and compare with same-level sibling trees that died out.

There's not a quick "see all the traits" method but if you open the Graphing dropdown at the upper right and just mouse over each trait, the bubbles for each subspecies in the taxonomy view will color-code according to their score in those traits -- so you can quickly pass your mouse through "Speed" "Size" "Diet" etc. and if there's a notable difference between two subspecies, you'll see it. If you click on one of the traits in the dropdown, the coloring will stick, and you'll be able to hover over the models to see their exact score.
Timecode link to youtube video showing this feature