Gradual genetic development is often represented as a tree similar to the one shown in the diagram.%0D%0A%0D%0A%0D%0A%0D%0AThis diagram suggests that%0D%0A%0D%0A a%0D%0Adifferent groups of organisms may have similar characteristics because of common ancestry.%0D%0A b%0D%0Aonly the most well-adapted organisms will survive.%0D%0A c%0D%0Aspeciation is a predictable event that happens every few years.%0D%0A d%0D%0Abiochemical differences show that no two organisms could ever have had a common ancestor.
