Process of Evolution: GENETIC DRIFT MICROEVOLUTION Flashcards
(26 cards)
What are the four factors that can alter the allele frequencies in a population?
genetic drift
natural selection
gene flow
mutation
TRUE OR FALSE:
“Each individuals has thousands of genes, any one of which could experience a mutation.”
TRUE
_________ is genetic exchange due to migration of fertile individuals or gametes between populations.
For example, if a nearby wildflower population consisted entirely of white flowers, its pollen (r alleles only) could be carried into our target population.
Gene flow
____________ is clearly a violation of the conditions necessary for the Hardy-Weinberg equilibrium.
Natural selection
_____________ is the only factor that generally adapts a population to its environment.
Natural selection
Over the long term, _________ is a very important to evolution because it is the original source of genetic variation that serves as the raw material for natural selection.
mutation
This requirement of the Hardy-Weinberg equilibrium is more likely to be met if the size of the population is ______ (large, small).
large (theoretically infinite)
A _________ is a change in an organism’s DNA.
mutation
Genetic drift at small population sizes often occurs as a result of two situations: the __________ effect or the _________ effect.
bottleneck, founder
A new _________ that is transmitted in gametes can immediately change the gene pool of a population by substituting the mutated allele for the older allele.
mutation
TRUE or FALSE:
“The smaller the sample, the greater the chance of deviation from an idealized result.”
TRUE
__________ tends to reduce differences between populations.
If extensive enough, it can amalgamate neighboring populations into a single population with a common genetic structure.
Gene flow
The two main causes of microevolution are __________ and ___________
drift, natural selection
An individual ________ allele may have greater impacts later through increases in its relative frequencies as a result of natural selection or genetic drift.
mutant
The _________ effect occurs when a new population is started by only a few individuals that do not represent the gene pool of the larger source population.
founder
TRUE or FALSE:
“The gene pool of a small population may not be accurately represented in the next generation because of sampling errors. “
TRUE
The ___________ theory provides a baseline against which we can compare the allele and genotype frequencies of an evolving population.
Hardy-Weinberg
__________ occurs even if the frequencies of alleles are changing for only a single genetic locus in a population while the others are at equilibrium.
Microevolution
____________ will continue to impact the gene pool until the population is large enough to minimize the impact of sampling errors.
Genetic drift
The ___________ effect occurs when the numbers of individuals in a larger population are drastically reduced by a disaster.
bottleneck
__________ occurs when changes in gene frequencies from one generation to another occur because of chance events (sampling errors) that occur when populations are finite in size.
Genetic drift
TRUE OR FALSE:
“At an extreme, a population could be started by single pregnant female or single seed with only a tiny fraction of the genetic variation of the source population.”
TRUE
__________ always favors the disporportionate propagation of favorable traits.
Selection/Natural selection
It is a generation-to-generation change in a population’s allele frequencies
Microevolution
