Natural Selection
What is natural selection?
The process by which organisms better adapted to their environment tend to survive and produce more offspring.
What is speciation?
The process by which new species arise from existing species.
What is genetic drift?
A change in allele frequencies in a population due to random sampling of organisms.
What is a gene pool?
The total collection of genes and alleles in a population
What is gene flow?
The transfer of genetic (genes) material between populations (organisms)
Give an example of natural selection in action.
The peppered moth, which changed color to better blend in with polluted trees.
Name one way populations can become isolated.
Geographical barriers, such as mountains or rivers.
How can genetic drift impact small populations?
It can lead to significant changes in allele frequencies, increasing the risk of extinction.
How does gene diversity affect a population?
Greater diversity can enhance survival by providing a wider range of traits.
How can gene flow affect genetic diversity?
It can increase diversity by introducing new alleles into a population.
How does natural selection lead to evolution?
It promotes the survival of advantageous traits, leading to changes in the population over time. (Survival of the fittest)
What is reproductive isolation?
When different species are unable to breed successfully due to various barriers.
What is the founder effect?
When a small group establishes a new population, leading to reduced genetic variation.
What factors can reduce a gene pool?
Inbreeding and population bottlenecks can reduce genetic diversity.
What is the impact of reduced gene flow on speciation?
What role do adaptations play in natural selection?
Adaptations are traits that improve an organism's ability to survive and reproduce in its environment.
How can environmental changes lead to speciation?
Changes can create new habitats and selective pressures, leading to adaptation and divergence.
In which type of population is genetic drift most likely to have a significant impact?
Small populations
If a population has a very limited gene pool, what is a potential consequence?
Reduced genetic variation, making it more vulnerable to disease or environmental change.
Give an example of gene flow in a plant species.
Pollen is transferred between two different populations of flowers.
Describe the concept of "survival of the fittest."
It refers to the idea that individuals with traits that enhance survival will reproduce more successfully.
Two populations of crickets, living in the same meadow, have different mating calls that prevent them from interbreeding. This is an example of which type of reproductive isolation?
Behavioral isolation
How does genetic drift differ from natural selection?
Genetic drift is random, while natural selection is a non-random process influenced by environmental pressures.
What process adds new alleles to a gene pool?
Mutations, migration
How does gene flow counteract the effects of genetic drift?
It can introduce new alleles, maintaining genetic diversity and reducing random changes.