Descent with Modification and The Evolution of Populations

These flashcards cover key concepts from the lectures on descent with modification, natural selection, evolutionary mechanisms, and speciation.

What is descent with modification?

The process by which species accumulate differences from their ancestors as they adapt to different environments over time.

What are the three key characteristics of life observed in the study of evolution?

1. Life is highly diverse. 2. Living things share many characteristics (unity of life). 3. Organisms are adapted for life in their environments.

What is natural selection?

A process in which individuals with certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

What is the Hardy-Weinberg equilibrium?

The state of a population in which no evolution is occurring, meaning allele frequencies are not changing.

What are prezygotic barriers?

Factors that prevent mating or fertilization between species, such as habitat isolation, temporal isolation, and behavioral isolation.

What is allopatric speciation?

Speciation that occurs when a population is geographically isolated, leading to the interruption of gene flow.

What are the mechanisms of evolution?

Natural selection, genetic drift, and gene flow.

What is genetic drift?

A process in which chance events cause unpredictable fluctuations in allele frequencies from one generation to the next, especially in small populations.

What is a hybrid zone?

A region where members of different species meet and mate, producing offspring of mixed ancestry.

What is the biological species concept?

A species is defined as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring.

What is sympatric speciation?

Speciation that occurs in populations that live in the same geographic area.

What are vestigial structures?

Features of an organism that are historical remnants of structures that served a function in the organism's ancestors.

How can plate tectonics affect evolution?

Plate tectonics can alter habitats, trigger extinction, and create new environments for adaptive radiations.

What is convergent evolution?

The evolution of similar features in independent evolutionary lineages.

What is the significance of fossils in understanding evolution?

Fossils provide evidence for the patterns of macroevolution, showing how groups of organisms arise, diversify, and fall over time.

What leads to balancing selection?

Selection that maintains two or more phenotypic forms in a population through mechanisms like heterozygote advantage.

What is the role of mutation in evolution?

Mutation is the ultimate source of genetic variation, providing the raw material for natural selection.