The number and location of bones of many fossil vertebrates are similar to those in living vertebrates.?

Question

Most biologist would probably explain this fact on the basis of....

A. the needs of the organisms
B. a common ancestor
C. the struggle for existance
D. the inheritance of acquired traits

Answer 1

Common ancestor. It's like having five fingers--it's not necessarily the ultimately best number of fingers to have, but the bone arrangement has been around since we got it from the actinopteryginii and possibly even before. We just happened to get it from the animal that happened to make it. Evolution can work in favor of dumb luck, occasionally.

Answer 2

Well, fish and mammals do not have the same number & types of bones (Fish don't have limbs), but all mammals do & maybe this is what you mean. This indicates that mammals had a common ancestor. Otherwise, it would mean that different organisms randomly evolved into similar bone patterns. Of course, all vertebrates still are very similar & probably evolved from a common ancestor also.