Question

Similarity in biochemicals, like the glucose used by virtually all living things for energy, provides evidence of what?

Answer 1

evolution

Virtually all living things use glucose for energy, but glucose is just one of many examples of biochemical compounds that are found in most or all living things. In fact the similarity in biochemical compounds between living things provides some of the best evidence for the evolution of species from common ancestors. A classic example is the biochemical compound called cytochrome c. It is found in all living organisms because it performs essential life functions. Only slight variations in the molecule exist between closely related species, as you can see in the Figure below . The molecule is identical in humans and their closest relatives, the chimpanzees. And even between humans and the single-celled tetrahymena  pictured in the Figure below  , the cytochrome c molecule is nearly 50 percent the same.