Biologists use molecular clocks to try to measure

-when a molecule was created
-how long molecules have existed
-when two species separated from a shared ancestor
-when two species will merge to become one species

Which of the following words best matches this definition: the process in which the best adapted organisms survive and pass on their traits, while those that are not well adapted do not survive to pass on their traits. question 3 options: acquired selection natural selection artificial selection organic selection