3.1 Flashcards
(30 cards)
What is evolution?
Evolution is the change in gene frequencies within a population from one generation to the next.
What is natural selection?
Natural selection is the process where organisms best adapted to their environment survive and reproduce, passing on their advantageous traits.
Who are the two scientists credited with the concept of natural selection?
Charles Darwin and Alfred R. Wallace.
What is selective pressure?
A nonrandom influence that affects which individuals survive or reproduce in a population.
What is genetic diversity, and why is it important?
Genetic diversity is the variation of heritable traits in a population. It is important because it allows populations to adapt to environmental changes.
What are the two main sources of genetic variation?
Mutation and genetic recombination.
How does mutation contribute to evolution?
Mutations introduce new genetic changes, which may be beneficial, neutral, or harmful.
What is genetic recombination?
The reshuffling of alleles during the formation of eggs and sperm, creating new trait combinations.
What invasive species is responsible for the decline of mammal populations in the Everglades?
The Burmese python (Python molurus bivittatus).
What hypothesis did Bob McCleery and his team test in 2012?
They tested whether Burmese pythons were responsible for the decline of marsh rabbits and other mammals in the Everglades.
How did the researchers test their hypothesis?
They captured, radio-tagged, and released marsh rabbits in areas with and without Burmese pythons to track their survival.
What is an invasive species?
A non-native species that causes economic, environmental, or human health harm.
What is coevolution?
A process where two species evolve in response to each other, such as predators and prey.
Why are species that never coevolved with a predator at a higher risk?
They may not have the necessary traits to defend against or escape the predator.
What is extinction?
The complete loss of a species from an area, either locally or globally.
What is extirpation?
The local extinction of a species from a particular area while still existing elsewhere.
What is the background rate of extinction?
The natural rate of species extinction before human influence, estimated at 1–2 species per million per year.
What is the current rate of extinction?
100 to 1,000 times higher than the background rate, largely due to human activity.
What are the five main factors affecting the pace of evolution and extinction?
Genetic diversity, Population size, Reproductive rate, Generation time, Strength of selective pressures.
What is genetic drift?
A random change in gene frequencies in a population over time.
What is the bottleneck effect?
A drastic reduction in population size that leads to the loss of genetic diversity.
What is the founder effect?
When a small group from a larger population becomes isolated and evolves differently due to limited genetic variation.
What is artificial selection?
The human-driven process of breeding organisms to enhance specific traits.
Give an example of intentional artificial selection.
Breeding domestic dogs for specific traits.
