Why are all the people on earth members of t he same biological species? a. all people have the same genetic makeup. b. all people originated from the continent of africa. c. all people have adaptations that allow them to live anywhere on earth. d. all people can mate with one another and have children.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?