AP Biology Evolution Flashcards

6013586740	homologous structures	structures in different species that are similar because of common ancestry	0
6013586741	vestigial structures	remnants of features that served important functions in the the organism's ancestors	1
6013586742	convergent evolution	the independent evolution of similar features in different lineages	2
6013586743	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
6013586744	gene pool	the aggregate of all of the alleles for all of the loci in individuals in a population	4
6013586745	population	a group of individuals of the same species that live in the same area and interbreed, producing fertile offspring	5
6013586746	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
6013586747	genetic drift	changes in the gene pool due to random events	7
6013586748	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
6013586749	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
6013586750	gene flow	the transfer of alleles into or out of a population due to the movement of fertile individuals or their gametes	10
6013586751	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
6013586752	disruptive selection	when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes	12
6013586753	stabilizing selection	acts against both extreme phenotypes and favors intermediate variants	13
6013586754	sexual selection	a form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates	14
6013586755	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
6013586756	diploidy	the state of being diploid, that is having two sets of chromosomes	16
6013586757	heterozygote advantage	when individuals who are heterozygous at a particular locus have greater fitness than do both kind of homozygous	17
6013586758	frequency-dependent selection	fitness of a phenotype declines if it becomes too common in the population	18
6013586759	speciation	the process by which one species splits into two or more species	19
6013586760	microevolution	changes over time in allele frequencies in a population	20
6013586761	macroevolution	the broad pattern of evolution over long time spans	21
6013586762	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
6013586763	reproductive isolation	the existance of biological barriers that impede members of two species from producing viable offspring	23
6013586764	hybrids	offspring that result from interspecific mating	24
6013586765	prezygotic barriers	impede mating or hinder fertilization if mating occurs (five types: habitat, temporal, behavioral, mechanical, gametic)	25
6013586766	post zygotic barriers	prevents hybrid zygote from developing into a viable fertile adult through reducing hybrid viability, reducing hybrid fertility, or hybrid breakdown	26
6013586767	allopatric speciation	gene flow is interrupted when a population is divided into geographically isolated subpopulations	27
6013586768	sympatric speciation	speciation occurs in populations that live in the same geographic area (usually occurs due to polyploidy, habitat differentiation, and sexual selection)	28
6013586769	polyploidy	extra sets of chromosomes due to accidents during cell division	29
6013586770	autopolyploid	an individual that has more than two chromosome sets that are all derived from a single species	30
6013586771	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
6013586772	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
6013586773	ribozyme	RNA that can also carry out a number of enzyme-like catalytic functions	33
6013586774	protobionts	collections of abiotically produced molecules surrounded by a membrane-like structure with simple chemical reactions (precursor of prokaryotic cells)	34
6013586775	endosymbiosis	mitochondria and chloroplasts were formally small prokaryotes that began living within larger cells	35
6013586776	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
6013586777	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
6013586778	phylogeny	the evolutionary history of a species or group of species	38
6013586779	systematics	study and classification of biodiversity and determining their evolutionary relationships	39
6013586780	phylogenetic tree	evolutionary history of a group of organisms represented in a branching diagram	40
6013586781	analogy	similarity due to convergent evolution	41
6013586782	homology	similarity due to shared ancestry	42
6013586783	clade	a group of species which includes an ancestral species and all of its descendants	43
6013586784	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
6013586785	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
6013586786	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
6013586787	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
6013586788	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