Microevolution Flashcards
What is an allele?
One of two or more alternative forms of a gene
What is a phenotype?
The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment
What is a genotype?
The genetic constitution of an individual organism
What is a gene pool?
The sum of all alleles in a population
Is phenotype or genotype observable? Which is genetic information?
Observable – Phenotype
Genetic Information – Genotype
Populations exhibit allelic, or what, variation?
Genetic
What is microevolution?
The generation-to-generation changes in allele frequency within a population.
What is the smallest evolution scale?
Microevolution
What are the five causes of microevolution?
Mutation, gene flow, nonrandom mating, genetic drift, and selection
What is mutation?
Changes the proportions of specific alleles in a population
What is the least important factor in microevolution and has very low rates?
Mutation
The ultimate source of genetic variation is what?
Mutation
What is gene flow?
Changes in allele (gene) frequency due to immigration or emigration into or out of the gene pool/population.
A mutated gene leads to what two types of proteins?
No protein or abnormal protein
What is nonrandom mating?
Individuals with certain genotypes sometimes mate with one another more commonly than is expected on a random basis
What is disassortative mating and what does it increase?
Preference for different genotypes or phenotypes and increases heterozygosity
What is assortative mating and what does it increase?
Preference for similar genotypes or phenotypes and increases homozygosity
What is genetic drift due to and affects what population size more?
Environmental events and small populations
What is genetic drift?
Change in frequency of an existing gene variation in the population due to random chance
Genetic drift can lead to what in small, isolated populations?
Loss of alleles
What is the Founder Effect?
Allele frequencies of the founding individuals in new populations differ from the allele frequencies in the population from which they came
A bottleneck event leads to loss and alteration of what?
Genetic variability
A bottleneck leads to a drastic reduction in what and is caused by what forces in the environment?
Population and natural forces like flooding, epidemic diseases, and wildfires
What is selection?
An unequal survival of genes across generations
Selections favors some individuals over others which typically leads to a phenotype with greater what usually increasing in the environment?
Fitness
What does disruptive selection do?
Removes intermediate phenotypes and is for both extremes
What does directional selection do?
Selection acts to eliminate one extreme from an array of phenotypes
What is stabilizing selection?
Selection acts to eliminate both extremes from an array of phenotypes
About what percent of humans of European descent immune to HIV and other infectious diseases?
10%
The Black Death of 1348-1350 killed blank million or what percentage of Europe’s population?
75 million or 30-60%
With the Black Death, the allele frequency for HIV and other infectious diseases went from 1:20,000 to 1:what?
1:10
Natural skin color is an what or what?
Adaptation or natural selection
What is the quantification of fitness?
Number of surviving offspring relative to other individuals
