Biology Unit 11 - Evolution

What is evolution?

Slow adaptations to an organism or species, enabling survival; effective natural selection.

Who is Darwin?

He studied genetics and animals, focusing on how traits were passed on, particularly from an isolated island.

What is a scientific theory?

An explanation of a set of related observations based on proven hypotheses verified by independent researchers.

What does “evolution due to the process of natural selection” mean?

Differences in survival and reproduction due to environmental conditions.

What are some environmental conditions that could affect reproductive success?

Climate, predators, habitat, food/water.

What are the four postulates of natural selection?

1. Variation, 2. Heredity, 3. Selective Pressure, 4. Reproductive Success.

What is variation in the context of natural selection?

Individuals within a population vary in their traits due to genetic variation and random mutations.

What is heredity regarding natural selection?

Some variations/traits are heritable and are passed from parents to offspring.

What is selective pressure?

A population can produce more individuals than can survive, leading to competition for limited resources.

What is reproductive success in natural selection?

Individuals with advantageous traits survive and reproduce over time, leading to evolutionary changes.

What is geographic distribution in evidence for evolution?

The geographical distribution of species shows that closely located species are often related.

What is fossil evidence for evolution?

Fossils represent ancient species, often simpler in form, and transitional fossils show intermediate states between ancestral and descendant forms.

What are vestigial organs?

Remnants of structures that had important functions in ancestral species but have lost their use in modern descendants.

What are homologous structures?

Body parts with the same structural design and origin in different organisms, indicating common ancestry.

What does comparative embryology suggest?

More closely related species have similar embryological development.

What does cellular and molecular evidence indicate?

Closely related species have similar molecular sequences.

What is divergent evolution?

One common ancestor evolves into two or more distinct species.

What is convergent evolution?

Distinct species become more similar over time due to similar environmental pressures.

What is coevolution?

Two species evolve in response to one another.

How can genetic change happen in a population?

Through natural selection, gene flow, genetic drift, and mutation.

What is gene flow?

The movement of alleles between populations, affecting genetic variation.

What is genetic drift?

Random changes in allele frequency within a population, often due to chance events.

What is the role of reproduction in population evolution?

Sexual reproduction increases genetic variation, critical for adaptation to environmental changes.

What is the Red Queen Hypothesis?

The idea that species must continuously adapt and evolve to survive against ever-evolving opposing species.