Ancestral Traits Flashcards

Questions and Answers

What are derived traits?

Derived traits are those that just appeared (by mutation) in the most recent ancestor.

What are ancestral traits?

Traits inherited from distant ancestors.

What is a homologous structure?

An organ or bone that appears in different animals, demonstrating descent from a common ancestor.

What is gametic isolation?

A type of prezygotic barrier where gametes come into contact, but no fertilization takes place. Signup and view all the answers

What is hybrid infertility?

Hybrid offspring that develop normally but are sterile. Signup and view all the answers

What is an adaptation?

A mutation or genetic change that helps an organism survive in its environment. Signup and view all the answers

What is artificial selection?

Intentional reproduction of individuals in a population with desirable traits. Signup and view all the answers

What is directional selection?

A mode of natural selection in which an extreme phenotype is favored. Signup and view all the answers

What is speciation?

The formation of new and distinct species in the course of evolution. Signup and view all the answers

What is sympatric speciation?

The process through which new species evolve from a single ancestral species while inhabiting the same region. Signup and view all the answers

What are vestigial structures?

Structures that have no apparent function and are remnants of past ancestors. Signup and view all the answers

What is mechanical isolation?

Biological features that prevent different species from interbreeding. Signup and view all the answers

What is an analogous structure?

Structures in different species having the same function but evolved separately. Signup and view all the answers

What is natural selection?

The differential survival and reproduction of individuals due to differences in phenotype. Signup and view all the answers

What is sexual selection?

Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex. Signup and view all the answers

What is selective pressure?

Any cause that reduces reproductive success in a portion of a population. Signup and view all the answers

What is stabilizing selection?

A type of natural selection in which the population mean stabilizes on a particular non-extreme trait value. Signup and view all the answers

What is disruptive selection?

Changes in population genetics where extreme values for a trait are favored over intermediate values. Signup and view all the answers

What is allopatric speciation?

Occurs when biological populations of the same species become isolated from each other. Signup and view all the answers

What is temporal isolation?

The capability for processes running on the same system to run without interferences concerning their temporal constraints. Signup and view all the answers

What is behavioral isolation?

A mechanism where two allopatric species do not mate because of differences in courtship behavior. Signup and view all the answers

Study Notes

Key Biological Terms and Definitions

Derived Traits: Traits that are newly appeared due to mutations in the most recent ancestor, leading to a new evolutionary branch.
Ancestral Traits: Traits inherited from distant ancestors, distinguishing them from derived traits.
Homologous Structures: Organs or bones in different animals that demonstrate anatomical similarities, indicating a shared common ancestor.
Gametic Isolation: A prezygotic barrier where gametes come into contact but do not fertilize.
Hybrid Infertility: Occurs when hybrid offspring, although developing normally, are sterile and cannot produce viable gametes. Example: mules (horse-donkey cross).
Adaptation: Genetic mutations or changes that enhance an organism's survival in its environment.
Artificial Selection: Deliberate breeding of individuals with desirable traits to promote certain characteristics within a population.
Directional Selection: A natural selection process that favors extreme phenotypes over others, shifting the population mean.

Evolution and Speciation Processes

Speciation: The process through which new and distinct species evolve from a common ancestor.
Sympatric Speciation: Evolution of new species from a single ancestral species while cohabiting the same geographical area.
Vestigial Structures: Anatomical features that serve no significant function, remnants of ancestors.
Mechanical Isolation: Reproductive barriers that prevent mating between different species due to biological features.
Analogous Structures: Structures in different species that share similar functions but evolved separately; no common ancestry.

Mechanisms of Natural Selection

Natural Selection: Differential survival and reproduction based on phenotypic differences, a core mechanism of evolution.
Sexual Selection: A form of natural selection driven by preference of one sex for specific traits in the other sex.
Selective Pressure: Factors that reduce reproductive success in part of a population, thereby influencing evolutionary change.
Stabilizing Selection: Type of natural selection that keeps the population mean stable around a non-extreme trait value.
Disruptive Selection: Selection favoring extreme trait values over intermediate ones, increasing trait variance and creating distinct population groups.

Isolation Mechanisms

Allopatric Speciation: Occurs when populations of the same species become geographically isolated, preventing genetic interchange.
Temporal Isolation: Mechanism preventing species from mating due to differences in timing of reproductive periods.
Behavioral Isolation: Occurs when two species do not mate due to differences in courtship behaviors, also known as ethological isolation.

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Description

Test your knowledge on ancestral and derived traits with this flashcard quiz. Learn the differences between traits inherited from distant ancestors and those that have evolved through recent mutations. Perfect for students interested in evolutionary biology.