Diversity of Life Part 2 Flashcards

Vocabulary flashcards created from General Biology BI 131 Chapter 12 lecture notes covering evolutionary mechanisms, geological history, speciation, taxonomy, and cladistics.

Darwinian Fitness

The contribution that an individual makes to the gene pool of the next generation in comparison to the contributions from other individuals.

Genetic Drift

A change in a gene pool due to chance alone, occurring when survival and reproduction are random.

Bottleneck Effect

A drastic reduction in population size that leads to the random loss of genes from the gene pool.

Founder Effect

A change in the gene pool occurring when a few individuals migrate to a new isolated habitat, losing some genes by chance.

Gene Flow

The genetic exchange among populations resulting from the migration of individuals or gametes.

Sexual Selection

A form of natural selection that depends on an individual's ability to obtain a mate through female choice or male competition.

Geological Record

The historical timeline of Earth recognized by geologists, divided into four broad eras each marked by distinctive life.

Precambrian Era

The geological era spanning from $4.6\text{ bya}$ to $541\text{ mya}$, encompassing Earth's formation and the earliest prokaryote and eukaryote fossils.

Paleozoic Era

The geological era from $541\text{ mya}$ to $252\text{ mya}$, marked by an explosion in ocean animal diversity, plant and animal land migrations, and ending with a mass extinction.

Mesozoic Era

The geological era from $252\text{ mya}$ to $66\text{ mya}$, characterized by the appearance of the first dinosaurs and the dominance of flowering plants.

Cenozoic Era

The geological era from $66\text{ mya}$ to today, marked by the extinction of dinosaurs, diversification of mammals, and emergence of modern humans.

Tectonic Plates

Large moving plates of Earth's crust floating on the hot mantle layer that continuously rearrange continental geography.

Macroevolution

Large-scale genetic change across the history of life, encompassing speciation and major evolutionary structural transitions.

Speciation

The evolutionary formation of new species from ancestral species.

Nonbranching Evolution

A mechanism of macroevolution in which an ancestral population changes gradually over time without splitting into multiple species.

Branching Evolution

A mechanism of macroevolution where an ancestral population splits into two or more distinct populations.

Species

A population whose members are capable of interbreeding with one another to produce healthy, fertile offspring.

Behavioral Isolation

A reproductive barrier where individuals of different species fail to mate because they identify species members through specific rituals.

Mating Time Differences

A reproductive barrier where species are prevented from interbreeding because they reproduce at different specific times.

Habitat Isolation

A reproductive barrier that prevents interbreeding because species live in slightly different habitats and do not meet.

Mechanical Incompatibility

A reproductive barrier occurring when members of different species cannot mate because their physical anatomies are incompatible.

Gametic Incompatibility

A reproductive barrier where sperm and egg gametes of different species cannot fertilize each other.

Hybrid Weakness

A post-zygotic reproductive barrier where offspring of two different species are unfit or sterile.

Graduated Model

A model of speciation where a species slowly acquires small adaptations to its environment over millions of years.

Allopatric Speciation

The formation of new species occurring when a physical or geographic barrier isolates populations from one another.

Sympatric Speciation

The emergence of a new species in the midst of parent species without geographic isolation, often through sudden genetic changes.

Taxonomy

The biological discipline concerned with the identification, naming, and classification of species.

Taxonomic Hierarchy

An ordered classification system running from the broadest category (Domain) down to the most narrow category (Species).

Domain

The broadest category of classification, categorizing all life into Bacteria, Archaea, and Eukarya based on cell type.

Scientific Name

A two-part binomial name assigned to a species, consisting of the capitalized Genus and lowercase species name, formatted in italics.

Phylogenetic Tree

A branching diagram representing a hypothesis about the evolutionary history and relationships of related species.

Clade

Any group of species that consists of an ancestral species and all of its descendants.

Cladistics

The scientific analysis and study of clades to classify organisms according to evolutionary relationships.