Modes of Natural Selection
What is stabilizing selection?
Stabilizing selection is when average traits are favored, and extreme traits are selected against. This keeps the population stable over time.
What is natural selection?
Natural selection is the process where organisms with favorable traits are more likely to survive and reproduce.
What is mutation?
Mutation is a random change in DNA that can introduce new traits into a population.
What is the biological species concept?
It defines a species as a group of organisms that can interbreed and produce fertile offspring.
What is macroevolution?
Macroevolution refers to large-scale evolutionary changes that occur over long periods.
What is directional selection?
Directional selection happens when one extreme trait is favored, causing the population to shift in that direction.
What role does variation play in natural selection?
Variation provides differences in traits, which allows some individuals to survive better than others.
Example: What is gene flow?
Gene flow is the movement of genes between populations when individuals migrate.
What is reproductive isolation?
Reproductive isolation occurs when groups cannot mate or produce fertile offspring.
What is speciation?
Speciation is the formation of new species from existing ones.
What is disruptive selection?
Disruptive selection occurs when both extreme traits are favored over the average, which can lead to two different groups forming.
Example: What is adaptation?
An adaptation is a trait that increases an organism’s chance of survival in its environment.
What is genetic drift?
Genetic drift is random changes in allele frequencies, especially in small populations.
What is a limitation of the biological species concept?
It cannot be applied to organisms that reproduce asexually.
What is adaptive radiation?
Adaptive radiation is when one species rapidly evolves into many different forms.
Can you give an example of directional selection?
An example is giraffes evolving longer necks because those with longer necks could reach more food.
Why is overproduction important?
Overproduction means more offspring are born than can survive, leading to competition for resources.
What is natural selection as an evolutionary agent?
It is the process that increases the frequency of beneficial traits over time.
What is the morphological species concept?
It classifies species based on physical traits and appearance.
Example: What is extinction?
Extinction is when a species completely dies out.
Why is disruptive selection important?
It can lead to speciation because populations may split into two distinct groups.
What is survival of the fittest?
It means individuals best suited to their environment are more likely to survive and reproduce.
What is non-random mating?
Non-random mating happens when individuals choose mates based on specific traits.
Why is defining species important?
It helps scientists understand biodiversity and how organisms evolve.
What is convergent evolution?
Convergent evolution happens when unrelated species develop similar traits due to similar environments.