Gap-fill exercise

Fill in all the gaps, then press "Check Answers" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. Note that you will lose points if you ask for hints or clues!
Evidence for is provided by and from analysis of similarities and differences in of organisms.

The combined effect of , environmental and natural can produce new .

Mutated in cells can be passed on to and may occasionally produce new .

The first living things developed from that could themselves.