This printable crossword puzzle on the topic of Ecology & Evolution has 10 clues. Answers range from 7 to 21 letters long. This crossword is also available to download as a Microsoft Word document or a PDF.
trait that helps an organism survive and reproduce
gradual change in species over time
when no members of a species are still alive
time it takes for half of the atoms in a radioactive element to decay
theory that species evolve during short periods of rapid change
difference between individuals of the same species
theory that evolution occurs slowly but steadily
well tested concept that explains a wide ranged of observations
millions of fossils that scientist have collected
fossil formed when minerals replace all or part of an organism