Honor Bio 12.1 Flashcards
(17 cards)
What is natural selection?
A process where organisms with beneficial traits survive and reproduce more, increasing those traits in the population.
What is genetic drift?
Random changes in allele frequencies, especially impactful in small populations.
What is variation in a population?
The presence of different alleles and traits among individuals.
What does fitness mean in natural selection?
An individual’s ability to survive and reproduce, passing genes to the next generation.
Define adaptation in biology.
A heritable trait that improves an organism’s survival and reproduction in a specific environment.
What are the five fingers of evolution?
Small population (genetic drift)
Non-random mating
Mutation
Gene flow (migration)
Natural selection
How does mutation affect evolution?
It introduces new alleles, adding genetic variation.
How does gene flow affect allele frequencies?
Movement of alleles between populations can introduce or remove traits.
What is non-random mating?
When individuals choose mates based on traits, influencing which alleles are passed on.
Why does genetic drift affect small populations more?
Random events have a greater impact when there are fewer individuals.
Can natural selection remove harmful traits?
Yes, if a trait reduces fitness, individuals with it are less likely to reproduce.
Compare the effect of natural selection and genetic drift on adaptation.
Natural selection leads to adaptation; genetic drift does not necessarily favor useful traits.
How would a bottleneck event affect allele frequencies?
It drastically reduces genetic diversity due to random survival of a few individuals.
How might a founder effect influence a new population’s gene pool?
A small group starts a population, so rare alleles can become common just by chance.
Predict what would happen to a harmful allele under natural selection.
It would decrease in frequency as affected individuals have lower fitness.
Predict what happens when gene flow increases between two different populations.
Genetic differences decrease, making the populations more similar.
Explain how natural selection can lead to speciation.
Over time, if different traits are favored in different environments, populations can become reproductively isolated and form new species.
