| A | B |
|---|
| The history of ancestors, e.g., parents, grandparents, great grandparents, that traces back all previous generations for any given organism | Ancestry |
| The "parent" species from which two or more separate species evolved | Common ancestor |
| "The father of evolution" who believed that a process called natural selection explains how organisms evolved over time | Charles Darwin |
| Changes in the genetic code | Mutations |
| The idea that organisms have adaptations that allow them to be best suited for the environment where they will survive and reproduce | Natural selection |
| The theory of evolution that states gradual changes in living organisms have resulted in more complex organisms | Organic evolution |
| The total number of different gene variations available to a species | Gene pool |
| A group of similar organisms that can interbreed and produce fertile offspring | Species |
| Theory that states that organisms have changed gradually over time to form new kinds of organisms (or new species) | Theory of evolution |
| The gradual formation of life from nonliving chemicals | Chemical evolution |
| The combined ideas of Alexander Oparin and J.B.S. Haldane of how life on Earth could have formed gradually from nonliving chemicals | Oparin-Haldane Hypothesis |
| Existing with oxygen | Aerobic |
| Existing without oxygen | Anaerobic |
| Organism able to make food from either the sun's energy or from other chemicals | Autotroph |
| Theory that explains the origin of mitochondria and chloroplasts in eukaryotic cells | Endosymbiotic theory |
| Containing a nucleus and other membrane-bound organelles | Eukaryotic |
| Organism unable to make food; require food from an outside source | Heterotroph |
| Containing no nucleus | Prokaryotic |
| A relationship between two organisms where at least one benefits | Symbiotic relationship |
| Any physical characteristic or behavior that helps an organism to better survive | Adaptation |
| The interaction among organisms to better obtain resources or mating opportunities over others in order to survive | Competition |
| Another term for evolution; the idea that all organisms share a common ancestor but that species change over time due to the natural selection of favorable adaptations | Descent with modification |
| The gradual change of living organisms over time | Evolution |
| The place where an organism lives | Habitat |
| The process of nature that favors organisms that are best adapted to their environment | Natural selection |
| Creating more offspring than can be supported by the environment | Overproduction |
| Organisms of the same species that live in the same place at the same time and compete for resources such as food and water | Population |
| The passing on of genes to the next generation | Reproductive success |
| The idea that organisms must complete with one another and that only the most fit will survive | Struggle for existence |
| Differences in a specific trait found within a population | Variation |
| Having a variety of traits resulting in differences within a species and among different species | Genetic diversity |
| The accumulation of differences that results in the formation of different species from a common ancestor; related species acquire different traits | Divergent evolution |
| The formation of a new species through the process of divergent evolution | Speciation |
| The rapid diversification and speciation from a single common ancestor often seen on islands | Adaptive radiation |
| The formation of a new species by geographic isolation | Allopatric speciation |
| Separation of a population due to a physical barrier; the separation can result in speciation | Geographic isolation |
| A geographically isolated population of a species that has its own distinct characteristics but is still capable of breeding with other populations of its own species | Subspecies |
| The inability of populations to interbreed due to any number of barriers | Reproductive isolation |
| A type of reproductive isolation between populations due to differences in courtship or other mating behaviors | Behavioral isolation |
| A type of reproductive isolation between populations due to differences in the size, shape, and/or location of genitalia | Mechanical isolation |
| A type of reproductive isolation that occurs when a species develops different reproductive cycles | Temporal isolation |
| Diagram that shows possible evolutionary relationships sometimes in proportion to evolutionary time | Phylogenetic tree |
| Diagram that shows relationships among organisms based on evolved adaptations, or characteristics | Cladogram |
| Characteristics (or adaptations) that are found in new species but are absent in past lineage | Derived characters |
| Features in different species that have similar functions but the internal structures are different; gives evidence of convergent evolution | Analogous structures |
| The study of structural similarities and differences among species | Comparative anatomy |
| The development of similar structures in different ancestral lines due to environmental pressures; unrelated species acquire similar traits | Convergent evolution |
| The study of embryos and their development | Embryology |
| Features in different species that have similar internal structures even though they may have different functions; gives evidence of divergent evolution | Homologous structures |
| Similarity that indicates a common origin or shared evolutionary ancestry | Homology |
| Structures that have no useful purpose | Vestigial organs |
| The study of how plants and animals are distributed around the world | Biogeography |
| Still existing as a living species | Extant |
| No longer existing as a living species | Extinct |
| The preserved remains of an entire organism or part of one | Fossil |
| Scientists who study the earth and rocks | Geologists |
| The idea that evolution occurs at a slow and steady (gradual) rate | Gradualism |
| Scientists who study the fossils found in sedimentary rocks | Paleontologists |
| The idea that evolution is not always gradual but that changes in a species may occur rapidly for short periods of time | Punctuated equilibrium |
| A technique for approximating the actual age of a fossil by measuring the amounts of radioactive isotopes presesnt | Radiometric dating |
| A method that ages a fossil as older or younger than other fossils based on its location in sedimentary rock layers | Relative dating |
| The various layers of rock found within sedimentary rock | Strata |
| Molecules that act as the building blocks for proteins | Amino acids |
| A protein molecule essential to all living cells | Cytochrome c |
| A molecule that contains genetic "instructions" for making proteins | DNA |
| Similarities in the order of nucleotides of DNA and RNA or in the order of amino acids of proteins that indicate common ancestry between organisms | Sequence homology |
