Bio111: Chapter 17

Reproductive Isolation

Prevents different species from interbreeding and helps maintain separate gene pools.

Geographical Isolation

Separation of populations by physical barriers such as mountains or rivers.

Ecological Isolation

Populations occupy different habitats within the same area and rarely encounter each other.

Behavioral Isolation

Differences in courtship or mating behaviors prevent interbreeding.

Temporal Isolation

Populations reproduce at different times, leading to isolation.

Mechanical Isolation

Physical differences in reproductive structures prevent successful mating.

Gametic Incompatibility

Sperm and egg cannot fuse due to biochemical differences.

Hybrid Inviability

Zygote forms but fails to develop properly, resulting in unviable offspring.

Hybrid Infertility

Hybrids are sterile and cannot reproduce.

Allopatric Speciation

Speciation occurring due to geographical isolation.

Sympatric Speciation

Speciation occurring without physical separation, driven by behavioral or ecological factors.

Extinction

The complete loss of a species from Earth.

Adaptive Radiation

Rapid diversification of a single ancestral species into multiple species adapted to different ecological niches.

Bilateral Symmetry

Organisms can be divided into mirror-image halves along one plane.

Biological Species Concept

Defines a species based on the ability to interbreed and produce viable offspring.

Morphological Species Concept

Defines species based on physical traits, although it can be subjective.

Genealogical (Phylogenetic) Species Concept

Defines a species as the smallest group of individuals sharing a common ancestor.

Instantaneous Speciation

Rapid speciation that occurs in one generation, often through polyploidy or hybridization.

Speciation Requirements

Requires reproductive isolation and genetic divergence.