L/g Roots & Vocab Wk11

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species

Back 1

A group whose members possess similar anatomical characteristics and have the ability to interbreed.

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biological species concept

Back 2

The definition of a species as a population or group of populations whose members have the potential in nature to interbreed and produce fertile offspring; a biological species is also called a sexual species.

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conspecific

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Of or belonging to the same species

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prezygetic barriers

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A reproductive barrier that impedes mating between species or hinders fertilization of ova if interspecific mating is attempted.

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postzygotic barriers

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Any of several species-isolating mechanisms that prevent hybrids produced by two different species from developing into viable, fertile adults.

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mechanical isolation

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a form of reproductive isolation that occurs because of an incompatibility in structure of the male and female sex organs.

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introgression

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The transplantation of genes between species resulting from fertile hybrids mating successfully with one of the parent species.

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gametic isolation

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is a prezygotic isolation in the most literal sense

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allopatric speciation

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A mode of speciation induced when the ancestral population becomes segregated by a geographic barrier.

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sympatric speciation

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A mode of speciation occurring as a result of a radical change in the genome of a subpopulation, reproductively isolating the subpopulation from the parent population.

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hybrid breakdown

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a decline in viability expressed in the F2 or later linebred generations compared to the F1 or P1.

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adaptive radiation

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

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polyploidy

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A chromosomal alteration in which the organism possesses more than two complete chromosome sets.

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autopolyploid

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A type of polyploid species resulting from one species doubling its chromosome number to become tetraploid, which may self-fertilize or mate with other tetraploids.

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habitat isolation

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refers to situations where two species may live in the same general area but live or reproduce in different habitats.

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behaviorial isolation

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An isolating mechanism in which two allopatric species do not mate because of differences in courtship behavior

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geographic barriers

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divides a single population into two sub-populations, A and B, preventing gene flow between them.

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Recognition concept of species

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The idea that specific mating adaptations become fixed in a population and form the basis of species identification.

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adaptive peak

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An equilibrium state in a population when the gene pool has allele frequencies that maximize the average fitness of a population's members.

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hybrid zone

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A region where two related populations that diverged after becoming geographically isolated make secondary contact and interbreed where their geographic ranges overlap.

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cohesion concept of species

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The idea that specific evolutionary adaptations and discrete complexes of genes define species.

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punctuated equilibrium

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A theory of evolution advocating spurts of relatively rapid change followed by long periods of stasis.

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macroevolution

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Evolutionary change on a grand scale, encompassing the origin of new taxonomic groups, evolutionary trends, adaptive radiation, and mass extinction.

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geological time scale

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A time scale established by geologists that reflects a consistent sequence of historical periods, grouped into four eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic.

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radiometric dating

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A method paleontologists use for determining the ages of rocks and fossils on a scale of absolute time, based on the half-life of radioactive isotopes.

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half-life

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The number of years it takes for 50% of an original sample of an isotope to decay.

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preadaptation

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a situation where an organism uses a preexisting anatomical structure inherited from an ancestor for a potentially unrelated purpose

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allometric growth

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The variation in the relative rates of growth of various parts of the body, which helps shape the organism.

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Paedomorphosis

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The retention in an adult organism of the juvenile features of its evolutionary ancestors

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heterochrony

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Evolutionary change in the timing or rate of development.

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homesis

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Evolutionary alteration in the placement of different body parts.

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species selection

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A theory maintaining that species living the longest and generating the greatest number of species determine the direction of major evolutionary trends.

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hipp

Back 33

horse

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hist

Back 34

tissue

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holo

Back 35

entire; whole

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homo

Back 36

man

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hort

Back 37

garden

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hybrid

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mongrel

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hydr

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water

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hygr

Back 40

wet; moist

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hypo

Back 41

beneath; under; less

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hyper

Back 42

above; beyond; over

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hypho

Back 43

weaving

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hypno

Back 44

sleep

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ic

Back 45

added to nouns to form adjectives

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ichthy

Back 46

fish