| A | B |
|---|
| species | a group of similar organisms that can mate with each other and produce fertile offspring; living things that share a large number of characteristics and adaptations and are identified as one kind of organism |
| Adaptation | a trait that helps an organism survive and reproduce; a variation that helps an organism survive; your thumb and a frog’s tongue are examples |
| Scientific theory | a well tested concept that explains a wide range of observations |
| Darwin | a naturalist who traveled to the Galapagos Islands on the coast of the South American continent, developed the scientific theory of evolution |
| Galapagos Islands | a chain of islands off of the South American continent where Darwin discovered many variations of species of animals |
| Natural selection | the process by which organisms best adapted to their environment survive and pass on their traits; a hypothesis that helps explain the diversity of organisms |
| Competition | the struggle between organisms for the limited resources in a habitat |
| Variations | any difference among members of the same species |
| Evolution | the gradual change in a population over time |
| Asexual reproduction | the reproductive process that involves only one parent and produces offspring that are identical to the parent |
| Sexual reproduction | the reproductive process that involves two parents who combine their genetic material to produce a new organism which differs from the parents |
| Diversity | the vast amount of difference among all animals species on earth |
| Habitat | the area or place where an organism lives; it could be a desert or an ocean |
| Population | all of the members of one species in a particular area |
| Zygotes | a fertilized egg; the offspring from each fertilized egg will have unique set of genes |
| Homologous structure | body parts that are structurally similar in related species; provide evidence that the structures were inherited from a common ancestor |
| fossil | the preserved remains or traces of an organism that lived in the past |
| extinct | a species that does not have any living members |
