I'm glad you're not stressed.
In light of the tree thing, what would you say about the line of reptiles from which mammals emerged, versus the one from which birds emerged?
I imagine the evolutionist would declare that at some unsubstantiated point, not demonstrated in the fossil record, the sturdy reptile branch of the tree somehow (randomly?) developed a clearly-defined fork, from which two smaller branches -- birds and mammals -- each managed to blunder along and develop in its own unique and unguided direction. Each of these two mini-branches were somehow possessed of the necessary genetic material to accomplish this fork in the tree. Is that the evolutionist's model?