The best explanation for the presence of vestigial pelvis and femurs in some snake and whale species is

a common ancestor that used these structures to perform one or more specific functions

Explanation:

A vestigial structure is an organ that has no obvious function in an organism, but it has been used by a past ancestor to perform one or more specific functions. Thus, vestigial structures have been retained in the course of evolution, but they lost their ancestral functions. Vestigial structures/organs can be detrimental for the organism because it is required energy to maintain them and they may suffer diseases (e.g., cancer). Some well-known examples of vestigial organs/structures include, among others, the wings of ostriches and cormorants, the human appendix, etc.

videntify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.identify the dna change shown in the diagram and explain how that change can result in the increased genetic diversity often seen among siblings.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".