Unit 13: Evolution and Natural Selection

What sparked Charles Darwin's development of the theory of evolution?

• His observations during the voyage on the HMS Beagle.

What are the key influences on Charles Darwin's theory of natural selection?

• Geologists Lyell and Hutton

• Thomas Malthus.

What does the principle of variation in natural selection refer to?

• Differences that exist within populations.

What is meant by overproduction in the principles of natural selection?

• More offspring are produced

• Than can survive.

What does competition refer to in the context of natural selection?

• Organisms compete for resources.

What is the meaning of survival of the fittest?

• Individuals with beneficial traits are more likely to:

  • Survive

  • Reproduce.

What is descent with modification?

• Favorable traits become more common over generations.

What does the fossil record provide as evidence for evolution?

• Shows gradual changes in organisms over time.

What are homologous structures?

• Same structure

• Different function.

Give an example of analogous structures.

• Bird wings

• Insect wings.

What are vestigial structures?

• Reduced or non-functional remnants of ancestors.

How does embryology support the theory of evolution?

• Similar embryos suggest common ancestry.

What does biogeography tell us about evolution?

• Species in similar environments evolve similarly.

How does molecular biology provide evidence for evolution?

• Similar DNA

• Proteins indicate evolutionary relationships.

What is genetic drift?

• Random changes in allele frequency

• Especially in small populations.

What is gene flow?

• Movement of genes between populations

• Through migration.

What role do mutations play in evolution?

• Source of new genetic variations.

How does natural selection function as a mechanism of evolution?

• Differential survival and reproduction of individuals

• With advantageous traits.

What are structural adaptations?

• Physical traits that enhance survival.

Give an example of a behavioral adaptation.

• Migration.

What are physiological adaptations?

• Internal body processes that help in survival.

What is heritable variation?

• Traits passed down through generations

• Contributing to evolutionary change.

Define fitness in the context of evolution.

• Ability of an organism to:

  • Survive

  • Reproduce.

What is artificial selection?

• Human-driven breeding for desired traits.

How do genetic mutations relate to evolution?

• They create variations that drive evolution.

What is the relationship between population genetics and evolutionary forces?

• They shape species over time.

How do environmental pressures influence evolution?

• They influence survival and adaptation.

What role does competition play in natural selection?

• Organisms compete for limited resources

• Which impacts survival.

What does 'survival of the fittest' emphasize?

• The advantage of individuals with beneficial traits.

Identify one piece of evidence from comparative anatomy that supports evolution.

• Homologous structures like the human arm

• Bat wing.

What is the significance of the Galápagos finches in Darwin's studies?

• They exhibited variations leading to insights on:

  • Adaptation

  • Speciation.

What do vestigial structures like the human tailbone indicate?

• Evidence of evolutionary ancestry.

How is convergent evolution related to biogeography?

• Species in similar environments evolve:

  • Similar traits

  • Despite different ancestors.

What aspect of molecular biology supports evolutionary relationships?

• The similarity of DNA and protein sequences.

Why is genetic drift particularly impactful in small populations?

• It's more likely to affect allele frequencies significantly.

What would be an example of an internal physiological adaptation?

• Venom production in certain species.

In Darwin's context, what does 'favorable traits' refer to?

• Traits that increase an organism's chances of:

  • Survival

  • Reproduction.

How do behavioral adaptations like hibernation improve survival?

• They allow organisms to conserve energy

• During unfavorable conditions.

Why is fitness considered a key component of evolution?

• It determines how well organisms can:

  • Survive

  • Pass on their traits.

How does artificial selection differ from natural selection?

• Artificial selection is human-driven

• While natural selection occurs naturally.