Frogs that laid their eggs on overhanging leaves had
higher reproductive success than frogs
that laid their eggs in the water, and this trait spread through the population.
What are the evolutionary mechanisms that alter the prevalence of a given allele?
Natural selection, genetic drift, and gene flow
are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population violates the Hardy-Weinberg assumptions, and evolution occurs.
What are the factors that govern microevolution?
Mechanisms of microevolution. There are a few basic ways in which microevolutionary change happens.
Mutation, migration, genetic drift, and natural selection
are all processes that can directly affect gene frequencies in a population.
Which of the following evolutionary mechanisms can alter the frequencies of existing genetic variation?
The three mechanisms that directly alter allele frequencies to bring about evolutionary change are
natural selection
, genetic drift, and gene flow. Natural selection is based on differential reproductive success. Individuals in a population vary in their heritable traits.
What are the terms natural selection and evolution not synonymous?
Why are the terms ‘natural selection’ and ‘evolution’ not synonymous? -Because
evolution occurs in populations
, not in individuals, while natural selection can act on individuals. -Because evolution can only change genotype frequencies while natural selection can only change allele frequencies.
What are the three types of natural selection?
- Stabilizing Selection.
- Directional Selection.
- Disruptive Selection.
Is natural selection and survival of the fittest the same?
Evolution and “survival of the fittest” are
not the same thing
. Evolution refers to the cumulative changes in a population or species through time. “Survival of the fittest” is a popular term that refers to the process of natural selection, a mechanism that drives evolutionary change.
What are the 5 causes of evolution?
There are five key mechanisms that cause a population, a group of interacting organisms of a single species, to exhibit a change in allele frequency from one generation to the next. These are evolution by:
mutation, genetic drift, gene flow, non-random mating, and natural selection
(previously discussed here).
What are the 5 steps of evolution?
In fact, it is so simple that it can be broken down into five basic steps, abbreviated here as VISTA:
Variation, Inheritance, Selection, Time and Adaptation
.
What is the evidence for evolution?
Five types of evidence for evolution are discussed in this section:
ancient organism remains, fossil layers, similarities among organisms alive today
, similarities in DNA, and similarities of embryos.
What are the three ways in which natural selection can change a distribution of traits?
Natural selection on polygenic traits can affect the distributions of phenotypes in three ways:
directional selection, stabilizing selection, or disruptive selection
.
What are the four processes of evolution?
Construct an explanation based on evidence that the process of evolution primarily results from four factors:
(1) the potential for a species to increase in number, (2) the heritable genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for limited resources, and (4) the
…
How do you explain natural selection?
Natural selection is the
process through which populations of living organisms adapt and change
. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.
How does genetic drift affect genetic variation?
Genetic drift can
result in the loss of rare alleles
, and can decrease the size of the gene pool. Genetic drift can also cause a new population to be genetically distinct from its original population, which has led to the hypothesis that genetic drift plays a role in the evolution of new species.
How does genetic drift affect allele frequencies?
The consequences of genetic drift are numerous. It
leads to random changes in allele frequencies
. Drift causes fixation of alleles through the loss of alleles or genotypes. Drift can lead to the fixation or loss of entire genotypes in clonal (asexual) organisms.
How does natural selection affect genetic variation?
The consequence of natural selection on the genetic structure and evolution of organisms is complicated. Natural selection
can decrease the genetic variation in populations of organisms by selecting for or against a specific gene or gene combination
(leading to directional selection).
