A biologist finds near-identical embryos in a fish and a chicken. This kind of finding counts as:

1. Natural selection describes how populations change: variation, overproduction, competition, survival of the fitter, inheritance. 2. Comparative embryology and biochemistry do not describe that process at all. 3. Instead they show that different species share ancestry — similar embryos, similar molecules. 4. So they are evidence for evolution having occurred, not part of its mechanism. 5. Offering them as features of natural selection was a recorded error; so was offering stabilising, disruptive and directional, which are types of selection. _Source: NECTA ACSEE 2023 Biology 133/2, Question 5: Organic Evolution_