1. Genes are what determine the traits organisms will have and will pass on. Since good traits tend to help organisms to survive, those genes will become more common in a species. This may eventually change the appearance of that species.
  2. The better an organism’s fitness for an environment, the more likely it is to survive and reproduce. The adaptations that an organism has will determine its fitness.
  3. Fossils are remains of organisms from the past. Fossils can be bones, impressions, molds, petrified remains (in amber(sap), ice, and tar). Those fossils found in rocks are aged based on the layer they are found in.
  4. Darwin was a naturalist that went on a 5 year voyage around the world. While on that voyage, he saw similar fossils in different continents, different structures on similar organisms (Galapagos tortoises and finches), and similarities between current organisms and the fossils.
  5. Variation between similar organisms on these islands lead to Darwin’s understanding that the environment may cause a change to the organism’s features.
  6. A group of organisms that can reproduce and have fertile offspring (they can also reproduce). Species evolve as traits are chosen for the fitness in an environment and then passed on.
  7. Nature chooses the traits that are the best fit for an environment. Those organisms that have that trait will have a better chance at surviving and reproducing. The more these organisms survive, the more common the trait becomes.
  8. Fossils. Homologous Structures - Similar structures in different organisms, that may perform different functions. Similar Embryo Development - organisms that are closely related have similar embryo structures. DNA - the more DNA organisms have in common, the more closely related they are.
  9. Overproduction occurs when organisms produce more offspring than will be able to survive. This helps evolution because those offspring that do live are generally more fit for that environment.
  10. Evolution occurs because organisms are constantly competing with each other for food, water, shelter, etc. Those organisms that have better traits will be more likely to survive. Therefore, the will be more likely to pass on their “better” traits, which will alter the species.
  11. The different variations in individual members of a species will allow nature to choose the best one. This determines which adaptations are more fit for that organisms and its environment
  12. “Survival of the fittest” means that those organisms that fit best in an environment will have a better chance at living. Fitness does not mean strongest, but could refer to smarts, camouflage, speed, metabolism, etc
  13. Vestigial structures are features that serve no purpose in a species but may have served a purpose for its ancestors (appendix). Gradualism is a form of evolution where the organisms slowly changes over a period of time without random interruptions of change. Descent with modification describes how organisms evolve as descendants of an organism pick up those adaptations that help it to survive and therefore change the appearance from what the ancestor looked like.