Terms : Hide Images
| 7860967315 | homologous structures | structures in different species that are similar because of common ancestry |  | 0 |
| 7860967316 | vestigial structures | remnants of features that served important functions in the the organism's ancestors |  | 1 |
| 7860967317 | convergent evolution | the independent evolution of similar features in different lineages |  | 2 |
| 7860967318 | Hardy-Weinberg | the frequencies of alleles and genotypes in a population will remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work |  | 3 |
| 7860967319 | gene pool | the aggregate of all of the alleles for all of the loci in individuals in a population |  | 4 |
| 7860967320 | population | a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring |  | 5 |
| 7860967321 | natural selection | a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics |  | 6 |
| 7860967322 | genetic drift | changes in the gene pool due to random events | 7 | |
| 7860967323 | 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 |  | 8 |
| 7860967324 | 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 |  | 9 |
| 7860967325 | gene flow | the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes | 10 | |
| 7860967326 | 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 |  | 11 |
| 7860967327 | disruptive selection | when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes |  | 12 |
| 7860967328 | stabilizing selection | acts against both extreme phenotypes and favors intermediate variants |  | 13 |
| 7860967329 | sexual selection | a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates |  | 14 |
| 7860967330 | 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) |  | 15 |
| 7860967331 | diploidy | the state of being diploid, that is having two sets of chromosomes | 16 | |
| 7860967332 | heterozygote advantage | when individuals who are heterozygous at a particular locus have greater fitness than do both kind of homozygous | 17 | |
| 7860967333 | frequency-dependent selection | fitness of a phenotype declines if it becomes too common in the population | 18 | |
| 7860967334 | speciation | the process by which one species splits into two or more species |  | 19 |
| 7860967335 | microevolution | changes over time in allele frequencies in a population | 20 | |
| 7860967336 | macroevolution | the broad pattern of evolution over long time spans | 21 | |
| 7860967337 | 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 | 22 | |
| 7860967338 | reproductive isolation | the existance of biological barriers that impede members of two species from producing viable offspring | 23 | |
| 7860967339 | hybrids | offspring that result from interspecific mating |  | 24 |
| 7860967340 | prezygotic barriers | impede mating or hinder fertilization if mating occurs (five types: habitat, temporal, behavioral, mechanical, gametic) |  | 25 |
| 7860967341 | post zygotic barriers | prevents hybrid zygote from developing into a viable fertile adult through reducing hybrid viability, reducing hybrid fertility, or hybrid breakdown | 26 | |
| 7860967342 | allopatric speciation | gene flow is interrupted when a population is divided into geographically isolated subpopulations |  | 27 |
| 7860967343 | sympatric speciation | speciation occurs in populations that live in the same geographic area (usually occurs due to polyploidy, habitat differentiation, and sexual selection) |  | 28 |
| 7860967344 | polyploidy | extra sets of chromosomes due to accidents during cell division |  | 29 |
| 7860967345 | punctuated equilibrium | the theory that in the evolution there are long periods of little morphological change punctuated by relatively short periods of significant change |  | 30 |
| 7860967346 | endosymbiosis | mitochondria and chloroplasts were formally small prokaryotes that began living within larger cells |  | 31 |
| 7860967347 | 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 |  | 32 |
| 7860967348 | 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 | 33 | |
| 7860967349 | phylogeny | the evolutionary history of a species or group of species |  | 34 |
| 7860967350 | systematics | study and classification of biodiversity and determining their evolutionary relationships | 35 | |
| 7860967351 | phylogenetic tree | evolutionary history of a group of organisms represented in a branching diagram |  | 36 |
| 7860967352 | analogy | similarity due to convergent evolution |  | 37 |
| 7860967353 | homology | similarity due to shared ancestry |  | 38 |
| 7860967354 | clade | a group of species which includes an ancestral species and all of its descendants | 39 | |
| 7860967355 | outgroup | a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying | 40 | |
| 7860967356 | maximum parsimony (Ockham's Theory) | a principle that states that when considering multiple explanations for an observation, one should first investigate the simplest explanation that is consistent with the facts |  | 41 |
| 7860967357 | Darwin's Theory (five parts) | 1. Variation 2. Overproduction 3. Competition 4. Survival of the fittest 5. Overtime, emergence of new species (new alleles) | 42 | |
| 7860967358 | Cryptic species | Species which look almost identical but that are very different in other traits | 43 | |
| 7860967359 | Monophyletic | A branch on a phylogenetic tree that contains all decscendants of a common ancestor | 44 | |
| 7860967360 | Abiogenesis | origin of life from nonliving matter | 45 | |
| 7860967361 | abiotic synthesis | formation of organic molecules from inorganic material | 46 | |
| 7860967362 | ozone shield | protect organisms from harmful UV rays | 47 | |
| 7860967363 | geologic timescale | division of the history of Earth into eras, periods and epochs | 48 | |
| 7860967364 | extinction | total disappearance of all members of a species | 49 | |
| 7860967365 | mass extinction | total disappearance of a large number a species within a few million years | 50 | |
| 7860967366 | extant | still in existance | 51 | |
| 7860967367 | fitness | ability to produce surviving offspring | 52 | |
| 7860967368 | morphological species concept | new species differ by physical characteristics known as diagnostic traits | 53 | |
| 7860967369 | evolutionary species concept | members of a species share distinct evolutionary pathway and common traits | 54 | |
| 7860967370 | phylogenetic species concept | a family tree is used to identify species based on a common ancestor | 55 | |
| 7860967371 | biological species concept | species are identified as separate because of reproductive isolation. | 56 | |
| 7860967372 | plate tectonics | branch of geology which follows the movement of pieces of Earth's crust which float on a lower, hot mantle layer | 57 | |
| 7860967373 | continental drift | change over time of the positions of the continents | 58 | |
| 7860967374 | fossil | remains and traces of evidence of past life | 59 | |
| 7860967375 | paleontology | study of the fossil record | 60 | |
| 7860967376 | index fossils | fossils used to identify deposits made at apparently the same time in different parts of the world, used for relative dating | 61 | |
| 7860967377 | absolute dating | relies on radiometric dating to assign an age to a fossil | 62 | |
| 7972266705 | evolution | descent with modification | 63 | |
| 7972296031 | strata | superimposed layers of sediment cover older layers of rock | 64 | |
| 7972311286 | palentology | the study of fossils | 65 |
