ap bio unit 7 flashcards

Adaption

a heritable trait that enhances an individual’s fitness

Adaptive Radiation

The emergence of numerous species from a common ancestor introduced into an environment, presenting a diversity of new opportunities and problems.

allele

alternative versions of a gene that produce distinguishable phenotypic effects

allopatric speciation

geographic separation of populations from a parent species and subsequent evolution

analogous structure

similiar structure that evolved separately in different lineages

antibiotic resistance

the ability of a microorganism to resist the effects of an antibiotic to which they were once sensitive

aritifical slection

the selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits

bottleneck effect

example of genetic drift where a natural disaster kills off a majority of the population, and the surviving population is no longer genetically representative of the og population

cladogram

diagram depicting patterns of shared characteristics among species

clades

a group of species that includes an ancestral species and all its descendant

common ancestor

an organism that is an ancestor of two different organisms that are not related to each otherc

convergent evolution

process where organisms, not closely related, independently evolve similar traits as a result of adapting to similar environments

directional selection

natural selection that favors individuals at one end of the phenotypic range

disruptive selection

natural selection that favors individuals on both extremes of a phenotypic range over intermediate phenotypesdiv

divergent evolution

process by which interbreeding populations or species diverges into two or more descendent species, resultign in becoming more dissimilar

emigration

movement of individuals out of a populatione

evolution

all the changes that have transformed life on earth from its earliest beginnings to the diversity that characterizes it today

fertility

the ability to produce offspring

founder effect

occurs when a few individuals become isolated from a larger population and the new population’s gene pool is not reflective of the og

gene flow

the flow of alleles in and out of the population reuslting frm the migration of individuals

gene pool

the total aggregate of genes in a population at any one time

genetic drift 

the unpredictable fluctuations in allele frequencies from one generation to the newxt because of the populations’s finite size

homologous structures

structures in different speices that are similar because of common ancestry

hybrid

an offspring that was given different genetic infromation for a trait from each parent

immigration

the influx of new individuals from new areasiso

isolation types

six different mechanims that prevent the egg and sperm from coming together

limited resources

a resource which cannot be made available ona scale which can sustain its composition rate

mutation

a rare change in dna of a gene ultimately creating genetic diversity

natural slection

Differential success in the reproduction of different phenotypes resulting from the interaction of organisms with their environment. Evolution occurs when natural selection causes changes in relative frequencies of alleles in the gene pool.

outgroup

a species or group of species that is closely related to the group of species being studied, but clearly not as closely related as any study-group members are to each other

phenotype

the physical and physiological traits of an organism, which are determined by its genetic makeup

phylogenetic tree

a branching diagram that represents a hypothesis about evolutionary relationships

population

a localized group of indivdiuals that belong to the same species

protobiont

an aggregate of abiotically produced molecules surrounded by a membrane or membrane-like structure

random mating

the choice of mates in which chance plays the biggest part

reproductive isolation

barriers that impeded members of two species from producing viable fertile hybrids

serial endosymbiosis

A model of the origin of eukaryotes consisting of a sequence of endosymbiotic events in which mitochondria, chloroplasts, and perhaps other cellular structures were derived from small prokaryotes that had been engulfed by larger cells.

sexual selection

natural selection for mating successs

speciation 

origin of new species in evolutions

species

a group whose members possess similar anatomic characteristics and have the ability to interbreed

stabilizing selection

natural selection that favors intermediate variants by acting against extreme phenotypes

sterility

incapable of producing offspring

sympatric speciation

involves speciation occuring within a parent species remaining in one location

variation

differences between numbers of the same species

vestigial organs

they are historical remnants of strucutres that had important functions in ancestors

viability

capable of living

hardy weinberg equillibrium

• no genetic drift

• random mating

• no mutations

• no gene flow

• no natural selection