Fossils of the Dorudon, an aquatic mammal that lived over 40 million years ago, show a whale-like animal that had small, underdeveloped hind limbs. Which best explains how fossils like the Dorudon support the theory that plant and animal life has evolved over time?

There are no answer choices so I think I have to answer on my own. Many sea animals evolve from land animals who have 4 limbs. These limbs gradually fade away, generation after generation. Today, whales still have tiny leg bones that have no use. Another example is snakes. If you look at snake bones, then you will spot small front and back limbs on them. This leads to believe that snakes and whales evolved from a 4 limbed creature that evolved into our modern animals.

Explanation:

they prove that animals evloved from a sinle anncestor

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.