morphological species concept - answera species is a distinct group of organisms with a unique set of morphological characteristics (unique external form). biological species concept - answerdefines a species as one or more population that can interbreed to produce fertile offspring but are reproductively isolated from other groups. reproductively isolated - answerWhen two species are prevented from interbreeding genetic heritage - answera particular set of genes and alleles that is typical of the species but different from that of all other species. Who proposed evolution? - answerCharles Darwin natural selection - answeran evolutionary process that adapts a population to its environment. What does evolution not say - answerEvolution in NO WAY says we evolved from monkeys • Evolution DOES NOT disprove intelligent design • Evolution DOES NOT have a direction • Nothing is more or less evolved • Evolution IS NOT a choice Evidence for evolution - answerSimilarity of life • Shared characteristics • Vestigial structures • Development • Distribution of similar life • Fossil record • Observation • Microevolution evolutionary tree - answerillustrates the evolutionary history of groups of organisms. phylogenetics - answergoal is to construct evolutionary trees that illustrate the patterns of species evolution. shared derived traits - answerevolutionary novelties shared by an ancestor and its descendants but not seen in groups that are not direct descendants of that ancestor homologous traits - answerare features that organisms share because they have inherited them from a common ancestor. vestigial organs - answerorgan that serves no useful function in an organism plate tectonics - answerThe slow movement of the continents over time relative to one another Microevolution - answeris a small change in a species • Not developing new species bottleneck effect - answerA change in allele frequency following a dramatic reduction in the size of a population Radioisotopes - answerunstable forms of elements that decay to more stable forms at a constant rate over time. macroevolution - answerrefers to large-scale changes in organisms, generally occurring over millions of years. adaptive radiation - answerAn evolutionary pattern in which many species evolve from a single ancestral species speciation - answerthe process in which one species splits to form two or more species that are reproductively isolated from each other. 4 mechanisms of evolution - answerThe 4 mechanisms are: • Natural Selection • Genetic Drift • Gene Flow • Mutation gene pool - answerthe sum of all the genetic information carried by all the individuals in a population. gene flow - answerthe movement of genes from one population to another. genetic drift - answera random process that can cause the gene pool of a population to change randomly from one generation to the next over time. mutations - answerare the ultimate source of all genetic variation and are the result of random changes in DNA sequences. artificial selection - answeris the process by which only individuals with certain inherited characteristics are allowed to breed. natural selection - answera nonrandom, directional process that shifts the genetic characteristics of a population in one direction that leads to adaptation over successive generations. adaptation - answerThe process by which a population as a whole becomes better matched to its habitat over successive generations adaptive traits - answergenetic characteristics that enable the individuals to function well, and therefore survive and reproduce better in a competitive environment. sexual selection - answerWhen individuals differ in inherited characteristics that affect their ability to get mates sexual dimorphism - answerthat males and females are distinctly different in appearance. sexual mimicry - answeroccurs when one sex mimics the opposite sex in its behavior, appearance, or chemical signaling. geographic isolation - answercan occur when populations of a single species become separated, or geographically isolated, from one another. allopatric speciation - answerThe formation of new species from geographically isolated populations ring species - answerdevelop when populations loop around a geographic barrier in which populations at the two ends of the loop are in contact with each other, yet individuals from these populations cannot interbreed. sympatric speciation - answerThe formation of new species in the absence of geographic isolation convergent evolution - answeroccurs when natural selection causes distantly related organisms to evolve similar structures in response to similar environmental challenges. atavistic trait - answerA hereditary trait that represents a reversion to an ancestral state. (human with tails, hair all over their bodies) biosphere - answerincludes all the organisms on Earth, together with the physical environments in which they live. ecology - answeris the scientific study of interactions