Terms : Hide Images
| 7585540496 | homologous structures | structures in different species that are similar because of common ancestry |  | 0 |
| 7585540497 | vestigial structures | remnants of features that served important functions in the the organism's ancestors |  | 1 |
| 7585540498 | convergent evolution | the independent evolution of similar features in different lineages |  | 2 |
| 7585540499 | gene pool | the aggregate of all of the alleles for all of the loci in individuals in a population |  | 3 |
| 7585540500 | population | a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring |  | 4 |
| 7585540501 | natural selection | a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics |  | 5 |
| 7585540502 | genetic drift | changes in the gene pool due to random events | 6 | |
| 7585540503 | founder effect | when a individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool differs from the source population |  | 7 |
| 7585540504 | bottleneck effect | when there is a severe drop in population size, certain alleles may be overrepresented among the survivors, others may be underrepresented, and some may be absent altogether |  | 8 |
| 7585540505 | gene flow | the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes | 9 | |
| 7585540506 | directional selection | when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting the frequency curve for the phenotypic character in one direction or the other |  | 10 |
| 7585540507 | disruptive selection | when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes |  | 11 |
| 7585540508 | stabilizing selection | acts against both extreme phenotypes and favors intermediate variants |  | 12 |
| 7585540509 | sexual selection | a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates |  | 13 |
| 7585540510 | sexual dimorphism | marked differences between the two sexes in secondary sexual characteristics, which are not directly associated with reproduction or survival (differences in size, color, ornamentation, and behavior) |  | 14 |
| 7585540511 | diploidy | the state of being diploid, that is having two sets of chromosomes | 15 | |
| 7585540512 | heterozygote advantage | when individuals who are heterozygous at a particular locus have greater fitness than do both kind of homozygous | 16 | |
| 7585540513 | frequency-dependent selection | fitness of a phenotype declines if it becomes too common in the population | 17 | |
| 7585540514 | speciation | the process by which one species splits into two or more species |  | 18 |
| 7585540515 | microevolution | changes over time in allele frequencies in a population | 19 | |
| 7585540516 | macroevolution | the broad pattern of evolution over long time spans | 20 | |
| 7585540517 | species | a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring- but do not produce viable, fertile offspring with members of other such groups | 21 | |
| 7585540518 | reproductive isolation | the existance of biological barriers that impede members of two species from producing viable offspring | 22 | |
| 7585540519 | hybrids | offspring that result from interspecific mating |  | 23 |
| 7585540520 | prezygotic barriers | impede mating or hinder fertilization if mating occurs (five types: habitat, temporal, behavioral, mechanical, gametic) |  | 24 |
| 7585540521 | post zygotic barriers | prevents hybrid zygote from developing into a viable fertile adult through reducing hybrid viability, reducing hybrid fertility, or hybrid breakdown | 25 | |
| 7585540522 | allopatric speciation | gene flow is interrupted when a population is divided into geographically isolated subpopulations |  | 26 |
| 7585540523 | sympatric speciation | speciation occurs in populations that live in the same geographic area (usually occurs due to polyploidy, habitat differentiation, and sexual selection) |  | 27 |
| 7585540524 | polyploidy | extra sets of chromosomes due to accidents during cell division |  | 28 |
| 7585540525 | punctuated equilibrium | the theory that in the evolution there are long periods of little morphological change punctuated by relatively short periods of significant change |  | 29 |
| 7585540526 | endosymbiosis | mitochondria and chloroplasts were formally small prokaryotes that began living within larger cells |  | 30 |
| 7585540527 | adaptive radiation | Period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill vacant ecological roles in their communities |  | 31 |
| 7585540528 | homeotic genes | master regulatory genes that determine such basic features as where a pair of wings and a pair of legs will develop on a bird or how a plant's flower parts are arranged | 32 | |
| 7585540529 | phylogeny | the evolutionary history of a species or group of species |  | 33 |
| 7585540530 | phylogenetic tree | evolutionary history of a group of organisms represented in a branching diagram |  | 34 |
| 7585540531 | analogous structure | similarity of structures in different species due to convergent evolution |  | 35 |
| 7585540532 | homologous structure | similarity of structures in different species due to shared ancestry |  | 36 |
| 7585540533 | clade | a group of species which includes an ancestral species and all of its descendants | 37 | |
| 7585540534 | Darwin's Theory (five parts) | 1. Variation 2. Overproduction 3. Competition 4. Survival of the fittest 5. Overtime, emergence of new species (new alleles) | 38 | |
| 7585540535 | Monophyletic | A branch on a phylogenetic tree that contains all decscendants of a common ancestor | 39 | |
| 7585540536 | Abiogenesis | origin of life from nonliving matter | 40 | |
| 7585540537 | abiotic synthesis | formation of organic molecules from inorganic material | 41 | |
| 7585540538 | ozone shield | protect organisms from harmful UV rays | 42 | |
| 7585540539 | geologic timescale | division of the history of Earth into eras, periods and epochs | 43 | |
| 7585540540 | extinction | total disappearance of all members of a species | 44 | |
| 7585540541 | mass extinction | total disappearance of a large number a species within a few million years | 45 | |
| 7585540542 | extant | still in existance | 46 | |
| 7585540543 | fitness | ability to produce surviving offspring | 47 | |
| 7585540544 | plate tectonics | branch of geology which follows the movement of pieces of Earth's crust which float on a lower, hot mantle layer | 48 | |
| 7585540545 | continental drift | change over time of the positions of the continents | 49 | |
| 7585540546 | fossil | remains and traces of evidence of past life | 50 | |
| 7585540547 | paleontology | study of the fossil record | 51 | |
| 7585540548 | absolute dating | relies on radiometric dating to assign an age to a fossil | 52 | |
| 7585540549 | Null Hypothesis | the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error. | 53 | |
| 7585540550 | Experimental Hypothesis | The hypothesis that in an experiment, the results of the experimental group will differ significantly from those of a control group, and that the difference will be caused by the independent variable (or variables) under investigation. | 54 |
