Which scenario would most likely result in thBirds and humans are theorized to have a common ancestor because they have homologous structures. Which evidence best supports this theory? They both have tails as embryos. They each have vestigial structures. They have analogous structures. They have different forms as adults.e extinction of one or more species? The water temperature of a pond decreases slightly, and the members of the pond populations adapt to the change. The conditions are abnormally dry for one season in a desert, resulting in the deaths of a few members of a snake population. A predatory fish is introduced into a lake, resulting in a dramatic decrease in the populations of smaller fish. A new plant species begins growing in a forest, resulting in a new food resource for many animal populations.
