Biodiversity and Evolution Review

A comprehensive set of practice flashcards covering evolution, adaptation, natural selection, speciation, and population genetics based on the lecture notes.

How is evolution defined in terms of population genetics?

Evolution is the relative change in genetic traits of populations that occurs over successive generations.

What is the difference between microevolution and macroevolution?

Microevolution is the gradual change in allele frequencies in a population over time, while macroevolution involves large-scale changes including the formation of new species or taxa.

What are the three categories of adaptations mentioned in the notes?

Structural adaptations, behavioural adaptations, and physiological adaptations.

Provide three examples of structural adaptations.

Camouflage, beak shape, and the hairy leaves of the Burnt Cape cinquefoil which help retain water.

What is a physiological adaptation?

A metabolic or physiologic adjustment within the cells or tissues of an organism in response to an environmental stimulus, such as a Harbour Seal’s heart rate slowing during dives to conserve oxygen.

What are three primary ways variation is achieved within a species?

Sexual reproduction, crossing over in meiosis, and mutations.

What is the significance of a germ line mutation?

It occurs in a sperm or egg cell and may be passed down to succeeding generations, acting as a significant source of genetic variation.

What three vegetables were derived from the wild mustard plant through artificial selection?

Broccoli, cauliflower, and cabbage.

Define the process of natural selection.

The process through which populations of living organisms adapt and change; individuals with adaptive traits are more likely to survive, reproduce, and pass those traits to offspring.

Distinguish between stabilizing, directional, and disruptive selection.

Stabilizing selection favours intermediate phenotypes; directional selection favours one extreme phenotype; disruptive selection favours both extremes over intermediate phenotypes.

What is industrial melanism?

An evolutionary effect in several arthropods, like the peppered moth, where dark pigmentation evolved in environments affected by industrial pollution such as soot and sulfur dioxide.

What is the difference between extirpation and extinction?

Extirpation is the local disappearance of a species in a specific geographic area, while extinction is the total termination of a species globally.

What did Georges Cuvier contribute to the study of evolution?

He developed paleontology, noted that deeper strata contained fossils more dissimilar to modern life, and proposed catastrophism.

What is Uniformitarianism and who proposed it?

Proposed by Charles Lyell, it is the theory that changes in the earth's crust result from continuous and uniform processes operating at the same rates in the past as today.

What was Jean-Baptiste Lamarck's hypothesis regarding acquired characteristics?

He incorrectly proposed the inheritance of acquired characteristics, suggesting that traits gained during an organism's lifetime (like a giraffe stretching its neck) could be passed to offspring.

What were the two main ideas proposed by Charles Darwin in "On the Origin of Species"?

1. Present forms of life have arisen by descent and modification from ancestral species. 2. The mechanism for modification is natural selection working over long periods of time.

What is the half-life of Carbon-14 and its effective limit for dating?

The half-life is approximately $5730\,\text{years}$, and it is most accurate for dating samples up to $50\text{-}60\,\text{thousand years}$ old.

Define homologous and analogous structures.

Homologous structures have the same evolutionary origin and structural elements but different functions; analogous structures evolved separately to perform similar functions but lack a common structural origin.

What is a vestigial structure?

An anatomical feature that no longer retains its function, such as the pelvic bones in whales or eye sockets in blind cave fish.

What is the difference between transformation and divergence in speciation?

In transformation, a new species replaces the old one gradually; in divergence (adaptive radiation), one or more species arise from a parent species that continues to exist.

List five types of prezygotic barriers.

Behavioural isolation, ecological/habitat isolation, temporal isolation, mechanical isolation, and gametic isolation.

Name and describe three postzygotic barriers.

Hybrid unviability (embryos die), hybrid sterility (offspring like mules cannot reproduce), and hybrid breakdown (next generation is weak or sterile).

Contrast Gradualism and Punctuated Equilibrium.

Gradualism describes evolution as slow and steady linear change; Punctuated Equilibrium describes long periods of stasis interrupted by rapid change.

What are the five conditions for a population to be in Hardy-Weinberg Equilibrium?

1. Large population; 2. Random mating; 3. No net mutations; 4. No migration; 5. No natural selection against any phenotype.

In the Hardy-Weinberg formula, what do $p^2$, $q^2$, and $2pq$ represent?

$p^2$ is the frequency of the homozygous dominant genotype, $q^2$ is the homozygous recessive genotype, and $2pq$ is the heterozygous genotype.

What are the two types of genetic drift?

The Founder effect (a few individuals start a new population) and the Bottleneck effect (a rapid decrease in population size due to a dramatic event).

How does gene flow differ from genetic drift?

Gene flow is the movement of alleles between populations due to migration, while genetic drift is the change in allele frequencies due to chance events in small populations.