Ch. 4 Reading Quiz (Ecology)

adaptation

evolution by natural selection

adaptive evolution

evolution by natural selection

allele

an alternate form of a gene that has slight differences in the exact arrangement and type of nucleic acids compared to other versions

allele frequency

the number of occurrences of an allele that one would expect to find in a population of a given size

allopatric speciation

speciation between two or more spatially disjunct (not in the same place) populations

biological species concept

the definition of a species as consisting of all individuals that can actually or potentially interbreed and produce viable, fertile offspring

chromosome

a tight coil of DNA, which is a double-stranded molecule of bonded nucleic acids

directional selection

a shift in the trait frequency distribution of an organism whereby the mean trait value tends to shift through time toward one or the other end of the original distribution; a form of natural selection

disruptive selection

a shift in a trait frequency distribution whereby the extremes of the frequency distribution become more common over time; a form of natural selection

dominant allele

an allele that codes for its trait even if there is only one copy of the allele at a genetic locus

ecotype

a population of a species with locally adapted traits

evolution

a change in gene frequency in a population over time

What are the four mechanisms of evolution?

mutation, gene flow, genetic drift, and natural selection

fitness

genetic contribution that an individual makes to future generations

gene

a sequence of deoxyribonucleic acid (DNA) that contains the code for a biological molecule with a particular physiological or behavioral function

gene flow

the movement of alleles from one population to another via the movement of organisms or their gametes across space

genetic drift

the removal of genes from a population over time through random mating between individuals or by the random death of individuals

genetic mutation

errors in the replication of DNA within a cell that create slight differences in nucleotide sequences, leading to novel alleles

genotype

a specific combination of alleles in an individual at a particular genetic locus

genus

a level in the taxonmic hierarchy

geographic isolating mechanism

a physical barrier that prevents organism dispersal and limits gene flow

heritable

transmissible from parent to offspring via the genetic inheritance of alleles

heterozygous

having two different alleles for a particular gene

homozygous

having two copies of the same allele for a particular gene

morphology

an organism’s appearance

natural selection

the differential survival and reproduction of individuals in a population in response to biotic and abiotic factors in their environment acting on heritable variation in traits of individuals

non-native species

a population founded by individuals transported by humans and released well outside their native range

phenology

the cyclic and seasonal events in the life of a plant or animal; also the study of cyclic and seasonal biological phenomena in relation to climate

phenotype

the specific observable physical, developmental, or behavioral trait of an organism; determined by the organism’s genotype

population

the largest groups of things under study, a group of individuals of the same species that can mate together, a group of individuals of the same species that is spatially distinct from other groups of individuals of the same species

recessive allele

an allele that codes for its trait only if there are two copies of the allele at a genetic locus

relative fitness

an individual’s contribution to the gene pool of the future generations relative to the contribution from other individuals in the same population

reproductive isolating mechanism

a mechanism that separate two evolutionary lineages, making it so they can no longer interbreed; all speciation requires a reproductive isolating mechanism

scientific name

the genus and specific epithet that provide a name for a species

sexual selection

evolutionary selection for traits that increase mating success rather than survival

speciation

the process by which two species arise from one common ancestral species

stabilizing selection

a change in a trait frequency distribution whereby the mean trait value does not change through time, but the variation away from that mean decreases over time

sympatric speciation

speciation that occurs when two (or more) population lineages occupy the same physical location but experience no gene flow between them

taxon

the singular form of a general term referring to biological groups at a variety of different evolutionary organizational levels from subspecies up to orders