Download Evolutionary Biology Key Terms

AP Biology Module 8 Key Terms •
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adaptation -­‐ a trait that makes a living thing better suited for survival in a particular environment. Adaptive radiation -­‐ when a single species or a small group of species evolve into several different forms that live in different ways. allopatric speciation -­‐ When gene flow is interrupted and a population is divided into geographically isolated subgroups. Behavioral adaptations -­‐ inherited traits that help an organism survive and reproduce in a given environment or responses to the environment. Behavioral isolation - differences in courtship and mating rituals prevent mating Biogeography - geographic distribution of species based on continental drift bottleneck effect -­‐ results from a drastic reduction of a population, often caused by a catastrophic event. Cenozoic Era -­‐ recent time; the age of mammals Charles Darwin -­‐ 1809 – 1882; developed a theory of evolution based on observations of fossils, living organisms, characteristics that enhance an organism’s chance of survival, and the environment. Coevolution -­‐ process whereby 2 species evolve in response to each other over time. Convergent evolution -­‐ process whereby unrelated organisms come to resemble one another because the live in similar environments Convergent evolution - similar features in different lineages; analogous structures have similar function but different origin cyanobacteria -­‐ photosynthetic bacteria; gave rise to gradual increase in atmospheric oxygen levels Descent with Modification -­‐This idea states that organisms come from ancestors that lived in the past and that had various adaptations based on the environment of which they lived. Directional Selection – natural selection which favors one extreme or the other. Disruptive Selection – natural selection which favors the extreme phenotypes. Endosymbiosis -­‐ the model that suggests that mitochondria and plastids were once small prokaryotes that began living within larger host cells. Evolution -­‐ a change in the frequency of an allele in a population over many generations. Fossils -­‐ Remains or traces of organisms provide evidence about the history of life on Earth. founder effect -­‐ results from a small population colonizing an area away from the larger population. Functional adaptations -­‐ traits that involve the internal functions or chemistry of an organism. Gametic isolation – sperm and egg are incompatible and no fertilization can occur. •
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Gene flow -­‐ the gain or loss of alleles from a population caused by the immigration or emigration of individuals. Genetic drift refers to evolution occurring through random changes in allele frequency within a gene pool due to chance. Genetic variation -­‐ the variety in alleles of genes within and among populations. gradualism -­‐ theory that evolution occurred slow and steady over time Habitat isolation - the physical barriers of the environment prevent mating. Hardy-­‐Weinberg equilibrium equation -­‐ simple equation used to discover the probable genotypic frequencies in a population and to track changes from one generation to another. Homology - anatomic and or molecular similarities present in an ancestral organism; passed down to descendants. Hybrid breakdown -­‐ Hybrid adults are feeble or do not survive Macroevolution -­‐large scale evolutionary changes that take place over long periods of time. Mass extinctions -­‐ huge numbers of species disappear over a relatively short period of time. Mechanical isolation - reproductive structures are incompatible and prevent fertilization. Mesozoic Era -­‐ middle time; the age of dinosaurs microevolution -­‐ the change of allelic frequency in a population over generations. mutations -­‐ any change in the nucleotide sequence of an organism’s DNA. Natural selection -­‐ the concept that individuals in a population exhibit variation in their heritable traits, and those organisms with traits that are best suited for the environment tend to produce more offspring than those that are less well suited. Paleozoic Era -­‐ ancient time; the many vertebrates and Invertebrates lived Postzygotic barriers -­‐ occur after the egg is successfully fertilized and has developed into a zygote. Prezygotic barriers -­‐ impede reproduction by preventing male and female sex cells from uniting based on physical or behavioral factors. protobionts -­‐ large organic molecules formed which acted like pre-­‐cells. Punctuated equilibrium -­‐ theory which proposes that sexually reproducing species will experience little evolutionary change for most of their geological history, remaining in an extended state called stasis. Reduced hybrid fertility -­‐ Hybrid adults are sterile or infertile Reduced hybrid viability -­‐ Hybrid embryos do not develop correctly Speciation -­‐ the evolution of a new species that occurs when two similar reproducing beings evolve to become too dissimilar to share genetic information or produce viable offspring. species -­‐ a group of organisms whose traits are so similar that they can successfully mate with each other and produce viable, fertile offspring. Stabilizing Selection – natural selection which favors the intermediate phenotypes. Structural adaptations -­‐ traits that involve the physical structure or anatomy of an organism. •
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Sympatric speciation -­‐ if gene flow is reduced by polyploidy, habitat differentiation, or sexual selection. Temporal isolation - different times of the year / seasons prevent mating. Vestigial structures -­‐ remnants of structures once used in extinct organisms are found in extant organisms