Macroevolution and Natural Selection

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Questions and Answers

What is macroevolution?

Evolutionary change above the species level (correct)

A type of natural selection

Evolutionary change within a species

A process that occurs in a single generation

What is a requirement for descent with modification by natural selection?

Only genetic variation that is heritable

Phenotypic variation within a population and genetic variation that is heritable (correct)

Only phenotypic variation within a population

Only differential survival among phenotypes

What is a result of mutations?

Increased fitness of an individual

Variation in genotypes (correct)

Extinction of a species

Creation of new species

What is a random form of microevolution?

Genetic drift Signup and view all the answers

What is required for fitness?

Survival AND reproduction Signup and view all the answers

What was the main reason for the dodo bird's extinction?

The birds did not have traits to learn to run away from predators. Signup and view all the answers

What is the main difference between natural selection and sexual selection?

Natural selection focuses on traits related to survival, while sexual selection focuses on traits directly associated with reproduction. Signup and view all the answers

What is the primary mechanism by which new genetic variation is introduced into a population?

Mutation Signup and view all the answers

What is the result of gene flow in a population?

An increase in genetic variation Signup and view all the answers

Why is it incorrect to think that humans are the 'goal' of evolution?

Because humans are not the pinnacle of evolution. Signup and view all the answers

What is the primary driver of microevolution in populations?

Non-random natural selection Signup and view all the answers

What is the ultimate goal of natural selection in a population?

Enhanced fitness through survival and reproduction Signup and view all the answers

Which of the following is NOT a requirement for speciation in sexually reproducing species?

Allopatry Signup and view all the answers

What is the primary mechanism by which genetic variation arises in a population?

Mutation Signup and view all the answers

Which process is responsible for increasing the frequency of phenotypes that decrease survival and reproduction?

Negative selection Signup and view all the answers

Study Notes

Macroevolution and Descent with Modification

Macroevolution is evolutionary change above the species level, forming new genera, families, orders, classes, phyla, kingdoms, and domains.
Descent with modification by natural selection requires:
- Phenotypic variation within a population (e.g., petal color or wing length)
- Differential survival among phenotypes
- Genetic variation that is heritable
- Genes acting in complex ways to produce phenotypes
Very few traits are determined by one gene

Microevolution

Populations evolve, not individuals
Mutations result from DNA copying errors and create variation in genotypes
Selection pressures are environmental (biotic and abiotic) factors that cause differential survival
Natural selection and sexual selection are non-random forms of microevolution
Genetic drift, gene flow, and mutation are random forms of microevolution

Natural Selection and Sexual Selection

Natural selection focuses on traits related to survival
Sexual selection focuses on traits directly associated with reproduction
Random mechanisms (mutation, gene flow, and genetic drift) contribute to genetic variation in populations

Fitness and Evolution

Fitness requires survival AND reproduction
Humility is required when considering human evolution – we didn't evolve as the "goal" of evolution
Simple organisms and humans have evolved over time, with no preconceived goal

Dodo Bird Example

Lacked traits to learn to run away from predators due to lack of predators
When explorers arrived, the birds didn't adapt to run away, leading to extinction due to a short time period to evolve

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Description

This quiz covers macroevolution, which is the formation of new genera, families, orders, classes, phyla, kingdoms, and domains. It also explores Darwin's theory of natural selection, also known as descent with modification.