How did earth's atmosphere become oxygen-rich?

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

The (blank) states that all loving things are made of cells.

Me.henley said, “in the rat race we call life, only the strong will survive.” he may have been referring to