AP Biology: Evolution Chapter 22/23/26 Flashcards

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