Biological Evolution and Natural Selection

These flashcards cover key concepts in biological evolution, natural selection, and species differentiation.

Adaptation

A process by which populations become better suited to their environment over generations.

Natural Selection

The process by which certain traits become more common in a population due to their contribution to survival and reproduction.

Evolution

Change in the frequency of traits in a population over generations.

Lamarck's Theory

Proposed that evolution occurs through the inheritance of acquired characteristics.

Darwin's Theory

Emphasized natural selection as the primary mechanism of evolution, with variation being essential.

Convergent Evolution

When unrelated species develop similar traits due to similar environmental pressures.

Homology

Similarities in structure or genetics among different species due to common ancestry.

Reproductive Isolation

A mechanism that prevents gene flow between populations, leading to speciation.

Prezygotic Isolation Mechanisms

Factors that prevent mating or fertilization between different species.

Postzygotic Isolation Mechanisms

Factors that prevent hybrid offspring from developing into viable, fertile adults.

Anagenesis

The gradual evolution of a single lineage over time.

Cladogenesis

Branching evolution, where a single ancestral species splits into two or more descendant species.

Allopatric Speciation

The formation of new species due to geographic isolation.

Sympatric Speciation

The evolution of new species from a common ancestor while inhabiting the same geographical area.

Vestigial Structures

Body parts that have lost their original function through evolution.

Molecular Homologies

Similarities in DNA and protein sequences among species, indicating a common ancestor.

Biological Species Concept

Defines species based on their ability to reproduce and produce fertile offspring.

Morphological Species Concept

Defines species based on physical and observable traits.

Ecological Species Concept

Defines species based on their ecological role and adaptations in the environment.