Darwin's Theory

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Across
  1. 2. a group of similar organisms that can mate
  2. 4. selection individuals better adapted to environment
  3. 5. theory well-tested concept that explains observations
  4. 6. effect caused by species producing offspring
  5. 8. remains or traces of an organism
  6. 9. effect caused by limited food
Down
  1. 1. helps an organism survive and reproduce
  2. 3. change in a species over time
  3. 7. any difference between individuals of same species