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Evolution Vocab
HW #7
| Term | Definition |
|---|---|
| analogous structures | structures that do not have a common evolutionary origin but are similar in function |
| artificial selection | selective breeding of plants and animals to promote the occurrence of desirable traits in offspring |
| catastrophism | theory that states that natural disasters such as floods and volcanic eruptions shaped Earth's landforms and caused extinction of some species |
| convergent evolution | process by which unrelated organisms independently evolve similarities (analogous structures) when adapting to similar environments |
| evolution | the gradual change in a type of organism over time |
| fossil | a trace of an ancient organism that has usually been preserved in sedimentary rock |
| homologous structures | similar structures that related species have inherited from a common ancestor |
| inheritance of acquired characteristics | Lamarck's theory that characteristics acquired during the lifetime of an organism can be passed onto offspring |
| natural selection | a natural process resulting in the evolution of organisms best adapted to the environment |
| population | a group of organisms that belong to the same species and live in the same area |
| uniformationism | this principle states that the same process that operate today operated in the past |
| vestigial structure | a structure that is inherited from ancestors but has lost much or all of its original function (ex: human appendix) |
| adaptation | a characteristic that improves an individual's ability to survive and reproduce in a particular environment |
| allele frequency | the number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene |
| coevolution | the process in which two or more species evolve in response to changes in each other |
| competition | a common demand by two or more organisms upon a limited supply of a resource (ex: food, water, space, etc.) |
| directional selection | form of natural selection in which the entire curve moves/shifts to a different direction |
| disruptive selection | form of natural selection in which a single curve splits into two |
| equilibrium population | a population in which allele frequencies and the distribution of genotypes do not change from generation to generation |
| fitness | ability of an organism to survive and reproduce in its environment |
| founder effect | change in allele frequencies as a result of the migration of a small subgroup of a population |
| gene flow | movement of alleles from one population to another |
| gene pool | combined genetic information of all the members of a particular population |
| genetic drift | a change in the allele frequency of a population as a result of chance events rather than natural selection |
| Hardy-Weinberg Principle | principle that allele frequencies in a population will remain constant unless one or more factors cause the frequencies to change |
| mutation | change in a DNA sequence that affects genetic information |
| population bottleneck | a period during which only a few individuals of a normally large population survive |
| predation | an interaction in which one organism kills another for food |
| sexual selection | a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates |
| stabilizing selection | form of natural selection by which the center of the curve remains in its current position |
| adaptive radiation | an evolutionary pattern in which many species evolve from a single ancestral species |
| allopatric speciation | the formation of new species in populations that are geographically isolated from one another |
| extinction | a term that typically describes a species that no longer has any known living individuals |
| isolating mechanism | any factor that acts to reduce or block the flow of genes between two populations |
| polyploidy | condition in which an organism has extra sets of chromosomes |
| postmating isolating mechanism | any structure, physiological function, or developmental abnormality that prevents organisms of two different species, once mating has occurred, from producing vigorous, fertile offspring |
| premating isolating mechanism | any structure, physiological function, or behavior that prevents organisms of two different species from exchanging gametes |
| reproductive isolation | separation of a species or population so that they no longer interbreed and evolve into two separate species |
| speciation | the formation of new and distinct species in the course of evolution |
| species | a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding |
| sympatric speciation | the formation of new species in populations that live in the same geographic area |
| amphibian | a vertebrate that lives part of its life on land and part of its life in water |
| arthropod | any member of the phylum Arthropoda, which includes insects, spiders, and crustaceans |
| conifer | a member of a class of tracheophytes (Coniferophyta) that reproduces by means of seeds formed inside cones and that retains its leaves throughout the year |
| endosymbiont hypothesis | proposes that early eukaryotic cells acquired the precursors of mitochondria and chloroplasts by engulfing certain types of bacteria |
| eukaryote | A cell that contains a nucleus and membrane bound organelles |
| exoskeleton | hard protective structure developed outside the body, as the shell of a lobster |
| hominoid | a human or a prehistoric relative of humans, beginning with the Australopithecines, whose fossils date back at least 4.4 million year |
| lobefin | a member of the fish order Sarcopterygii; ancestors of today's lobefins gave rise to the first amphibians, and ultimately to all tetrapod vertebrates |
| mammal | a member of the chordate class Mammalia, which includes vertebrates with hair and mammary glands |
| mass extinction | event in which many types of living things become extinct at the same time |
| plate tectonics | a theory stating that the earth's surface is broken into plates that move |
| primate | monkeys, apes, and humans |
| prokaryote | a unicellular organism that lacks a nucleus and membrane bound organelles |
| protocell | a structure similar to a cell but not that is nonliving |
| reptile | a group of amphibians was evolving adaptations to drier conditions who have three major adaptations to survive on earth |
| ribozyme | an enzymatic RNA molecule |
| spontaneous generation | a hypothesis stating that life could arise from nonliving matter |
| archaea | one of the three domains of life |
| bacteria | prokaryotic organisms that lack a nucleus |
| biodiversity | the variety of life in the world or in a particular habitat or ecosystem |
| class | the taxonomic category of classifying organisms which falls between phylum and order |
| DNA sequencing | determining the order of nucleotide bases in a gene or DNA fragment |
| domain | a taxonomic category above the kingdom level; the three domains are archaea, bacteria, and eukarya |
| eukarya | one of three domains consisting of the five kingdoms plantae, protista, animalia, chromista, and fungi |
| family | the taxonomic category below order and above genus |
| genus | the taxonomic category that consists of a number of similar, closely related species |
| kingdom | the second largest taxonomic group, consisting of closely related phyla |
| order | the taxonomic group containing one or more families |
| phylogeny | the evolutionary history of a species or group of related species |
| phylum | the taxonomic group below kingdom and above class |
| scientific name | the two-part scientifically recognized name given to an organism consisting of its genus and species |
| systematics | study of the diversity of life and the evolutionary relationships between organisms |