AP Biology Evolution Flashcards

5860795882	homologous structures	structures in different species that are similar because of common ancestry	0
5860795883	vestigial structures	remnants of features that served important functions in the the organism's ancestors	1
5860795884	convergent evolution	the independent evolution of similar features in different lineages	2
5860795885	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
5860795886	gene pool	the aggregate of all of the alleles for all of the loci in individuals in a population	4
5860795887	population	a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring	5
5860795888	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
5860795889	genetic drift	changes in the gene pool due to random events	7
5860795890	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
5860795891	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
5860795892	gene flow	the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes	10
5860795893	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
5860795894	disruptive selection	when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes	12
5860795895	stabilizing selection	acts against both extreme phenotypes and favors intermediate variants	13
5860795896	sexual selection	a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates	14
5860795897	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
5860795898	diploidy	the state of being diploid, that is having two sets of chromosomes	16
5860795899	heterozygote advantage	when individuals who are heterozygous at a particular locus have greater fitness than do both kind of homozygous	17
5860795900	frequency-dependent selection	fitness of a phenotype declines if it becomes too common in the population	18
5860795901	speciation	the process by which one species splits into two or more species	19
5860795902	microevolution	changes over time in allele frequencies in a population	20
5860795903	macroevolution	the broad pattern of evolution over long time spans	21
5860795904	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
5860795905	reproductive isolation	the existance of biological barriers that impede members of two species from producing viable offspring	23
5860795906	hybrids	offspring that result from interspecific mating	24
5860795907	prezygotic barriers	impede mating or hinder fertilization if mating occurs (five types: habitat, temporal, behavioral, mechanical, gametic)	25
5860795908	post zygotic barriers	prevents hybrid zygote from developing into a viable fertile adult through reducing hybrid viability, reducing hybrid fertility, or hybrid breakdown	26
5860795909	allopatric speciation	gene flow is interrupted when a population is divided into geographically isolated subpopulations	27
5860795910	sympatric speciation	speciation occurs in populations that live in the same geographic area (usually occurs due to polyploidy, habitat differentiation, and sexual selection)	28
5860795911	polyploidy	extra sets of chromosomes due to accidents during cell division	29
5860795912	autopolyploid	an individual that has more than two chromosome sets that are all derived from a single species	30
5860795913	allopolyploid	an individual that has more than two chromosome sets due to two different species interbreeding and after several generations can change a sterile hybrid into a fertile polyploid. Allopolyploids are fertile when mating with each other but cannot interbreed with either parent species	31
5860795914	punctuated equilibrium	the theory that in the evolution there are long periods of little morphological change punctuated by relatively short periods of significant change	32
5860795915	ribozyme	RNA that can also carry out a number of enzyme-like catalytic functions	33
5860795916	protobionts	collections of abiotically produced molecules surrounded by a membrane-like structure with simple chemical reactions (precursor of prokaryotic cells)	34
5860795917	endosymbiosis	mitochondria and chloroplasts were formally small prokaryotes that began living within larger cells	35
5860795918	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	36
5860795919	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	37
5860795920	phylogeny	the evolutionary history of a species or group of species	38
5860795921	systematics	study and classification of biodiversity and determining their evolutionary relationships	39
5860795922	phylogenetic tree	evolutionary history of a group of organisms represented in a branching diagram	40
5860795923	analogy	similarity due to convergent evolution	41
5860795924	homology	similarity due to shared ancestry	42
5860795925	clade	a group of species which includes an ancestral species and all of its descendants	43
5860795926	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	44
5860795927	maximum parsimony	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	45
5860795928	molecular clock	a yardstick for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates	46
5860795929	horizontal gene transfer	a process in which genes are transferred from one genome to another through mechanisms such as exchange of transposable elements and plasmids, viral infection and perhaps fusion of organisms	47
5860795930	Darwin's Theory (five parts)	1. Variation 2. Overproduction 3. Competition 4. Survival of the fittest 5. Overtime, emergence of new species (new alleles)	48
5861142922	Cryptic species	Species which look almost identical but that are very different in other traits	49
5861158564	Monophyletic	A branch on a phylogenetic tree that contains all decscendants of a common ancestor	50
5861181945	Abiogenesis	origin of life from nonliving matter	51
5861186853	abiotic synthesis	formation of organic molecules from inorganic material	52
5861198293	last universal common ancestor (LUCA)	a common ancestor to all organisms that live and had lived on Earth	53
5861207699	protocell	organic polymers enclosed in a membrane	54
5861213527	ozone shield	protect organisms from harmful UV rays	55
5861219781	geologic timescale	division of the history of Earth into eras, periods and epochs	56
5861227824	extinction	total disappearance of all members of a species	57
5861233770	mass extinction	total disappearance of a large number a species within a few million years	58
5861241201	extant	still in existance	59
5861296530	fitness	ability to produce surviving offspring	60
5861310526	morphological species concept	new species differ by physical characteristics known as diagnostic traits	61
5861321312	evolutionary species concept	members of a species share distinct evolutionary pathway and common traits	62
5861330965	phylogenetic species concept	a family tree is used to identify species based on a common ancestor	63
5861339799	biological species concept	species are identified as separate because of reproductive isolation.	64
5861362122	plate tectonics	branch of geology which follows the movement of pieces of Earth's crust which float on a lower, hot mantle layer	65
5861376591	continental drift	change over time of the positions of the continents	66
5861408409	fossil	remains and traces of evidence of past life	67
5861418334	paleontology	study of the fossil record	68
5861437022	index fossils	fossils used to identify deposits made at apparently the same time in different parts of the world, used for relative dating	69
5861455654	absolute dating	relies on radiometric dating to assign an age to a fossil	70