Biogeography, Diversity Scales, and Evolutionary History

Vocabulary flashcards covering ecological diversity scales, experimental pseudoreplication, and historical biogeography based on the lecture transcript.

Biogeography

The field of ecological study examining patterns of species composition over time based on geographic location and spatial scale.

Pangaea

The most recent supercontinent or megacontinent in which all of Earth's land was connected as a single landmass.

Gamma diversity

The regional species pool comprising all species found across an entire region, indicating the potential diversity for localities within that area.

Alpha diversity

The measure of diversity at a specific local scale or locality, shaped primarily by local environmental physiology, microclimates, and species interactions.

Beta diversity

The comparison or change in species diversity between two different communities or localities within a landscape.

Pseudoreplication

The methodological error of treating multiple samples from the same population or location as independent replicates when they only represent a single piece of evidence.

Species richness

A basic count of the total number of distinct species present in a community.

Species diversity

A measurement of community diversity that counts the number of species while also accounting for their relative abundance.

Alfred Russel Wallace

The $19\text{th}$-century naturalist recognized as the father of biogeography who independently co-developed the theory of natural selection alongside Charles Darwin.

Wallace's line

A biogeographical boundary drawn through the Malay Archipelago separating distinct faunal zones where species distributions differ markedly despite geographic proximity.

Latitudinal diversity gradient

The broad global pattern, first documented by Alfred Russel Wallace, demonstrating that species diversity generally declines as latitude increases away from the tropics.

Laurasia and Gondwana

The two major landmasses formed during the initial breakup of the supercontinent Pangaea.

Vicariance

The splitting of an organism's geographic range into discontinuous parts by a physical barrier (such as tectonic plate movement, flooding, or fallen trees) that prevents gene dispersal.

Ratites

A group of large, flightless birds (including emus) historically hypothesized to have diverged from a single common ancestor via the vicariant breakup of Pangaea.