Here are the four postulates of natural selection, according to Charles Darwin:
1. variability - refers to different mutations that create different species
2. heritability - refers to the genes that are passed from one organism onto its descendants
3. overproduction of offspring - refers to the fact that more "children" is born than dies
4. natural selection - refers to those organisms that survive because they adapt to their surroundings better than those who will die
Answer: A. tropical plants grow on Antartica during summer months.
Explanation:
The PAX-6 gene is a gene that translates to the PAX-6 protein that serves as a transcription factor needed to activate certain genes that functions in the development of the eyes. While PAX-6 gene may look like it produces different functions for different species (such as formation of the compound eye in insects vs. formation of a single lens eye in vertebrates), it does not. It does in fact only regulate the genes required for the formation of the eyes. Absence or mutation of the PAX-6 gene will cause aniridia or absence of the iris, opaque lens and cornea, and a dysfunctional retina. Also, the function of the PAX-6 protein is conserved throughout evolution of species.
