5. which is not one of darwin's four main ideas of natural selection?

a. organisms produce more offspring than can survive.
b. evolution always improves organisms.
c. there is differential reproduction among better-adapted organisms.
d. individuals in a population vary in many traits.

allowed for the prediction of the properties of missing elements.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

it is called the mitotic spindle