Question | Answer |
what is gradualism it exerted a strong influence on darwins thinking | the idea that profound change can take place through the cummulitave effect of slow but continuous process (hutton and lyell |
actual father of evolution but had the inheritance of acquired traits as the mechanism otherwise known as use and disuse | lamarck |
what are the two major points of darwins orgin of species | 1. many species of organisms presently inhabiting earth are desendants of ancestral species that were diffrent form the modern species
2. the mechanism to the process is natural selection |
what is natural selection | the process in which populations can change over generations if individuals that posess certain heritable traits leave more offspring than other individuals |
what is evolutionary adaptation | an accumulation of inherited charateristics that enchance an organisms ability to survive and reproduce in a specific enviroment |
a change over time in the genetic composition of a population | evolution |
hypothesis that each strata corosponds in time to a catastrophe that destroyed many of the species living there at the time | catastrophism |
the idea that tie same geologic processes from gradualism are operating today as in the past and at the same rate | uniformitarianism |
what did darwin mean when he used the phrase decent with modification | as the descendents of an ancestral organism spilled into various habitats over millions of years they accumulated diverse modifications that fit them to specific ways of life |
two main ideas darwin developed in the orgin of species | 1. evolution explains lifes unity and diversity 2. natural selection is a cause of adaptive evolution |
process of selecting and breeding individuals with desired traits | atrifical selection |
similarity resulting from common ancestry | homology |
remnants of structures that may have served important functions in the organisms ancestors | vestigal organs |
the geographic distribution of species | biogeography |
species which is found only in a specific area | endemic |
what factors produce the variation that makes evolution possible | mutation and sexual recombination |
waht is the primary mechanism of adaptive evolution | natural selection |
what factors can alter a populations genetic composition | natural selection, genetic drift, gene flow |
what is the diffrence between microevolution and macroevolution | microevolution is change in the makeup of a population from generation to generation and macroevolution is the origination of new taxonomic groups (new abilities or features) |
why are populations important as the units of evolution | populations are the only units in which change in heritable variation from generation to generation can be observed |
what causes microevolution | small population size, migration, net mutation, non random mating, natural selection |
what causes the variation that makes evolution possible | sexual recombination and mutation |
why are mutations more rapid in microorganisms | they have a more rapid rate of reproduction |
why id sexual recombination more important than mutations in terms of evolution | sexual recombination is the way in which these mutations are spread throughout the community without it the mutation would die with the organism in which it occured |
what are the three factors that can alter a populations genetic composition | genetic drift, gene flow, and natural selection |
how does natural selection work | by accumulating and maintaining favorable genotypes in a population fitting them to their new enviroment increasing the frequency of certain genotypes |
why does natural selection have no efect on neutral variation | natural selection selects only aginst phenotyipc traits that give an organism an advantage or puts them at a disadvantage |
why cant natural selection produce perfect organisms | natural selection can only select among traits that already exist and when helpful modifications occur they are usually a compromise |