Modern organisms have some similarities to organisms that are now extinct. What is one possible explanation for this?

Answer:
Darwin's theory its simple thus that do not evolve shall dissolve meaning if an organism cannot keep up with the environment around it it will die off and if it can it will evolve.
Explanation:being that there are many species of cat that prolly come from one organism they all evolved according to there needs
Answer:
fossils
Explanation:
Fossils document the existence of now-extinct past species that are related to present-day species.