evolution Flashcards
(22 cards)
What is the difference between convergent and divergent evolution?
Convergent = similar traits evolve in different species. Divergent = one species evolves into different forms.
What is variation and why is it important for evolution?
Variation = differences in individuals. It’s important because it allows natural selection to act.
What are the sources of variation in a population?
Mutation, sexual reproduction, gene flow.
What is speciation?
The formation of a new species.
What are the steps of speciation?
isolation,
mutations/variation,
natural selection,
inability to interbreed.
What are fossils and how are they formed?
Fossils are preserved remains or traces of an ancient organism. Formed by quick burial, pressure, and mineralization.
How do you find the age of a fossil?
Relative dating (rock layers) and absolute dating (radiometric methods).
How does comparative anatomy provide evidence for evolution?
Homologous structures suggest a common ancestor.
How does comparative embryology provide evidence for evolution?
Similar embryos suggest shared ancestry.
What is the difference between homologous and analogous structures?
Homologous = same structure, different function. Analogous = different structure, same function.
What is the theory of natural selection?
Increase or decrease in allels due to environmental pressure.
The best-adapted individuals survive and reproduce, passing on traits.
Name three body conditions that need to be regulated.
Body temperature, blood sugar, water levels.
How is artificial selection different from natural selection?
Artificial = humans select traits. Natural = nature selects. Artificial is faster, but reduces genetic diversity.
How did Darwin’s finches evolve on the Galapagos Islands?
Isolated populations adapted to different environments (e.g., food), leading to different beak shapes.
What are four ways genetic diversity is created?
Gene flow, genetic drift, natural selection, mutation.
What is an example of natural selection in action?
The peppered moth during the Industrial Revolution — dark moths became more common in polluted areas.
How does artificial selection affect genetic diversity?
It reduces genetic diversity by selecting only specific traits over generations.
What are the three types of fossils used as evidence for evolution?
Transitional fossils, trace fossils, and body fossils.
How does DNA similarity provide evidence for evolution?
Similar DNA sequences show that species are genetically related.
What is the difference between allopatric and sympatric speciation?
A: Allopatric = geographic isolation. Sympatric = no physical barrier, but species evolve separately.
What is parallel evolution?
When two related species evolve in similar ways after their split from a common ancestor.
what are the different types of variation
inherited variation, acquired variation
