Biology Evolution Concepts

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Questions and Answers

What is directional selection?

Natural selection with no clear preferential direction

Natural selection favoring individuals at one end of the phenotypic range (correct)

Natural selection favoring individuals at both ends of the phenotypic range

Natural selection favoring intermediate variants

What is disruptive selection?

Natural selection in which individuals at the upper and lower ends of the curve have higher fitness than those near the middle.

What is stabilizing selection?

Natural selection that favors intermediate variants by acting against extreme phenotypes.

What are homologous structures?

Structures in different species that are similar due to common ancestry. Signup and view all the answers

What are analogous structures?

Body parts that share a common function but not structure. Signup and view all the answers

What are vestigial structures?

A structure that is present in an organism but no longer serves its original purpose. Signup and view all the answers

What is convergent evolution?

Evolution toward similar characteristics in unrelated species. Signup and view all the answers

What is divergent evolution?

Evolution of one or more closely related species into different species. Signup and view all the answers

What is coevolution?

Process by which two species evolve in response to changes in each other. Signup and view all the answers

What is artificial selection?

Breeding organisms with specific traits to produce offspring with identical traits. Signup and view all the answers

What is natural selection?

A natural process resulting in the evolution of organisms best adapted to the environment. Signup and view all the answers

What is sexual selection?

When individuals select mates based on heritable traits. Signup and view all the answers

What is the order of classification?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. Signup and view all the answers

What is gene flow?

Movement of alleles from one population to another. Signup and view all the answers

What is the bottleneck effect?

Genetic drift resulting from the reduction of a population, typically by a natural disaster. Signup and view all the answers

What is the founder effect?

Genetic drift that occurs when a few individuals become isolated from a larger population. Signup and view all the answers

What is a mutation?

A change in a gene or chromosome. Signup and view all the answers

What is camouflage?

The hiding of something as a result of its appearance. Signup and view all the answers

What is mimicry?

The ability of an animal to look like another more harmful animal. Signup and view all the answers

What is reproductive success?

Likelihood of an individual contributing fertile offspring to the next generation. Signup and view all the answers

Study Notes

Directional Selection

Refers to natural selection where individuals with traits at one end of the phenotypic spectrum are favored.
Results in increased survival or reproductive success for those individuals compared to others.

Disruptive Selection

A type of natural selection where individuals at both extremes of the phenotypic curve have higher fitness.
Favors organisms that exhibit traits that diverge from the average, promoting diversity within a population.

Stabilizing Selection

Natural selection that favors intermediate phenotypes and acts against extreme variants.
Helps maintain population stability by reducing variation in traits.

Homologous Structures

Similar structures found in different species due to shared ancestry.
Examples include similar bone structures in humans and whales, indicating evolutionary relationships.

Analogous Structures

Body parts that perform similar functions but arise from different evolutionary origins.
An example includes the wings of birds and insects, which serve the same function but have different structures.

Vestigial Structures

Structures that exist in organisms but no longer serve their original purpose.
Examples include the human appendix and whale pelvic bones, remnants of evolutionary history.

Convergent Evolution

Occurs when unrelated species independently evolve similar traits due to adapting to similar environments.
Results in analogous structures despite no recent common ancestry.

Divergent Evolution

The process where closely related species evolve different traits adapting to varied environments.
Leads to homologous structures among these species as they adapt differently over time.

Coevolution

A reciprocal evolutionary process where two species influence each other's adaptation and evolution.
Common in predator-prey relationships and mutualistic interactions between species.

Artificial Selection

The intentional breeding of organisms with desirable traits by humans.
Results in offspring that consistently exhibit selected traits, often seen in agriculture and pet breeding.

Natural Selection

A foundational mechanism of evolution where organisms better adapted to their environment survive and reproduce.
Drives the evolution of species over time, favoring advantageous traits.

Sexual Selection

A form of natural selection based on mate choice and competition, influenced by heritable traits.
Traits favored in this selection may enhance mating success rather than survival.

Order of Classification

The hierarchical structure of biological classification includes: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Organizes and categorizes living organisms based on shared characteristics.

Gene Flow

The movement and exchange of alleles between populations.
Can introduce new genetic variation, impacting evolution and adaptation.

Bottleneck Effect

A form of genetic drift occurring when a population's size is drastically reduced, often due to a natural disaster.
Results in a loss of genetic diversity and a gene pool that may not represent the original population.

Founder Effect

A genetic drift phenomenon where a small group from a larger population establishes a new population.
This new population's gene pool may differ significantly from the original group, often leading to reduced genetic diversity.

Mutation

A change in an organism's DNA sequence, which can result in new traits.
Mutations are a primary source of genetic variation and can drive evolution.

Camouflage

Adaptations that allow organisms to blend in with their surroundings, enhancing survival.
Effective camouflage can protect species from predators by reducing visibility.

Mimicry

The ability of one organism to resemble another, often harmful species.
Provides an evolutionary advantage by deterring predators through mistaken identity.

Reproductive Success

Refers to the likelihood that an individual will produce fertile offspring that survive to reproductive age.
A key measure of fitness in evolutionary biology, influencing population dynamics and evolution.

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Explore the key concepts of directional, disruptive, and stabilizing selection in natural selection through these flashcards. This quiz will deepen your understanding of how different selection processes influence evolutionary outcomes.