Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

37 Cards in this Set

  • Front
  • Back

Adaptive Radiation

-a burst of genetic divergences from a lineage gives rise to many new species


-reduction in population size so severe that it reduces genetic diversity


-evolutionary adaption of an existing structure for a completely new purpose

gene pool

-all the alleles of all the genes in a population

-pool of genetic recources

lethal mutation

-mutation that alters phenotype so drastically that it causes death


- populations speciate while in contact along a common border

sexual dimorphism

-difference in appearance between males and females of a species


-evolutionary pattern in which a lineage persists with little to no change over time

allele frequency

-abundance of a particular allele among members of a population


-the joint evolution of two closely interacting species

-each species is a selective agent for traits of the other


-refers to a species that no longer has living members

genetic drift

-change in allele frequency due to chance alone


-large scale evolutionary patterns and trends


- localized group of individuals belonging tothe same species with the potential to interbreed

sexual selection

-mode of natural selection in which some individuals out reproduce others of a population because they are better at securing mates


- speciation occurs within a population with no physical barrier

allopatric speciation

-Speciation by geographic isolation

directional selection

-shiftsthe range of variation in traitsin one direction

founder effect

-after a small group of individuals found a new population, allele frequencies in the new population differ from those in the original population

genetic equilibrium

-the frequencies ofalleles and genotypes in a population remainconstant over the generations despite meiosisand sexual reproduction


- Changes in the allele frequenciesof a population

reproductive isolation

-the end of gene flowbetween populations


-process by which new species arise

balanced polymorphism

- two or more alleles in highfrequency in a population

-can result from environmental pressures that favor heterozygous individuals

disruptive selection

-mode of natural selection in which traits at the extremes of a range of variation are favored over intermediate ones

gene flow

-movement of alleles into and out of a population


-mating among close relatives

neutral mutation

-a mutation that has no effect on survival or reproduction

stabilizing selection

-mode of natural selection in which the intermediate forms of a trait are favored over extreme forms

How do mutations cause microevolution?

-change in alleles cause change within in a population

How are changes in allele frequency measured?


How is sexual dimorphism advantageous to organisms?

-it leads to sexual selection which allows the traits most advantageous to survival to be past on

Why does the harmful HbS allele persist at high frequencies in areas where malaria is rampant?

-When the Hbs allele shows up in heterozygous individuals it makes them resistant to malaria

Describe a few factors that reduce a populations diversity:


Explain the various mechanisms of reproduction isolation with suitable examples:


How does allopatric speciation occur?

-Occurs when a physical barrier seperates a population and puts a great distance between them

-Ex: River or desert

Explain sympatric and parapatric speciation:

-Parapatric speciation occurs while a popultion is still connected along a common border

-Sympatric speciation occurs without an sort of physical barrier