Chapter 11--> Evolution Of Population Flashcards
What does a population share?
A common gene pool
What does genetic variation increase?
The chances that an individual will survive
What does genetic variation lead to?
Phenotype variation
What are Allele Frequencies?
Relative frequency of an allele at a particular locus in a population
What is hybridization?
The process of an animal or plant breeding with an individual of another species or variety.
How do populations evolve?
Variation in populations is determined by the genes present in the population’s gene pool, which may be directly altered by mutation
What is evolution?
The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth
What is microevolution?
Evolutionary change within a species or small group of organisms, especially over a short period
What is normal distribution?
A type of continuous probability distribution in which most data points cluster toward the middle of the range, while the rest taper off symmetrically toward either extreme
What is directional selection?
Individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other
What is stabilizing selection?
A type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value
What is distruptive selection?
A mode of natural selection in which extreme values for a trait are favored over intermediate values
What is gene flow
The transfer of genetic material from one population to another
What is genetic drift?
The change in the frequency of an existing gene variant in a population due to random chance
Genetic drift is also known as what?
The Wright Effect
What is the bottleneck effect?
Sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts
What is founder effect?
The founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
What is intrasexual selection?
competition between members of the same sex for access to mates
What is intersexual selection?
Where members of one sex choose members of the opposite sex
What is Hardy Weinberg Equilibrium
A principle stating that the genetic variation in a population will remain constant from one generation to the next
What is the equation for Hardy Weinberg equilibrium
p2+2pq+q2=1
What is p2?
Dominant homozygous frequency (AA)
What is 2pq?
Heterozygous frequency (Aa)
What is q2?
Recessive homozygous frequency (aa)
What does Hardy Weinberg Equilibrium predict?
The genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors
What are the 5 conditions?
- Very large populations
- No emigration or immigration
- Random mating
What is speciation?
The formation of new and distinct species in the course of evolution
What happens in species inbreed?
Their offspring are infertile
What is reproductive isolation?
Members of diffrent populations can not mate successful
What are the types of isolation?
- Behavioral
- Geographic
- Temporal
What is behavioral isolation?
Occurs when mismatches in mating traits prevent mating between two species or populations
What is geographic isolation?
Mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow
What is temporal isolation?
When two or more species reproduce at different times
What is divergent isolation?
Evolutionary pattern in which species sharing a common ancestry become more distinct due to differential selection pressure which gradually leads to speciation over an evolutionary time period
What is convergent evolution?
When species occupy similar ecological niches and adapt in similar ways in response to similar selective pressures
What are the two types of evolution?
- Divergent Evolution
- Convergent Evolution
What is extinction?
The dying out or extermination of a species
What is punctuated equilibrium?
The hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change
What is adaptive radiation?
The diversification of a group of organisms into forms filling different ecological niches
