Biogeography Lecture Flashcards

Vocabulary flashcards covering the definitions of biogeography, diversity scales (alpha, beta, gamma), and the principles of island biogeography from Dr. Elisa Cabrera-Guzmán's lecture.

Biogeography

The study of patterns of species composition and richness across geographic locations.

Plate tectonics

The movement of tectonic plates on the surface of the earth that reconfigured landmasses throughout geological history.

Global patterns of species richness factors

Influenced by geographic area and isolation, evolutionary history, and global climate.

Negative relationship (Latitude/Diversity)

A pattern where higher latitude results in lower diversity.

Positive relationship (Latitude/Diversity)

A pattern where higher latitude results in higher diversity.

Unimodal relationship (Latitude/Diversity)

A pattern where middle latitudes have higher species diversity.

Species diversification rate

Calculated as $\text{Speciation rate} - \text{Extinction rate}$.

Alpha Diversity

The number of species (Species Richness) in a specific community or in a defined area, such as the number of fish species in a single lake in California.

Gamma Diversity

Species richness over a larger geographic area, such as the total number of fish species in all lakes in California.

Beta Diversity

A value that relates alpha to gamma diversity, representing the rate of change of species composition among an environment or geographic gradient; calculated as $\frac{\text{gamma}}{\text{average alpha}}$.

Minimum differentiation

A state where all local communities are identical, alpha diversity equals gamma diversity (e.g., $\alpha = 5$, $\gamma = 5$), and beta diversity equals $1$.

Maximum differentiation

A state where local communities are completely different, gamma diversity equals alpha diversity multiplied by the number of sites (e.g., $5 \times 3 = 15$), and beta diversity equals the number of sites ($N$).

Island Biogeography (Small/High Isolation)

A condition characterized by lower immigration and higher extinction rates.

Island Biogeography (Large/Low Isolation)

A condition characterized by higher immigration and lower extinction rates.

Productivity in Tropics

High terrestrial productivity leads to larger carrying capacities, larger population sizes, and lower extinction rates.