Biogeography: Distribution and Abundance

Flashcards covering key vocabulary terms related to biogeography, species distribution, dispersal mechanisms, and evolutionary patterns.

Biogeography

The study of the distribution of species and ecosystems in geographic space and through geological time.

Buffon's Law

Despite similar environments, different regions contain distinctly different plants and animals.

George Buffon

Credited with the first principle of biogeography, describing Buffon's Law.

Alfred Russel Wallace

Known as the 'Father of Biogeography' for his research on flora and fauna distribution in the Amazon Basin and Malay Archipelago, and for developing a system of zoogeographic regions.

Alexander von Humboldt

Developed the theory of 'the unity of nature' and is attributed with laying the foundations of Phytogeography, known for describing vegetation zones.

Phytogeography

The study of the distribution of plants.

Local origin of a species

One of two factors, along with subsequent spread, viewed by Darwin and Wallace as determining species distribution, meaning a species doesn't originate everywhere at once.

Convergent Evolution

The independent evolution of similar features in species from different lineages, such as pitcher traps evolving independently in multiple plant lineages.

Subsequent spread of species

One of two factors, along with local origin, viewed by Darwin and Wallace as determining species distribution, dependent on barriers, corridors, and dispersal abilities.

Dispersal (Biogeography)

A main hypothesis for a taxon's distribution, involving the movement of organisms from their origin to new areas.

Vicariance

A main hypothesis for a taxon's distribution, involving the separation of populations through the rise of a geographic barrier.

Long-range migration

Seasonal movement of organisms, generally linked to the seasonal availability of food.

Barriers to migration

Physical, environmental/climatic, or temporal obstacles that can prevent the movement of organisms, sometimes leading to vicariance within a population.

Explosive fruits

A mechanism of seed dispersal where tension created by the drying and shrinking of the fruit wall causes seeds to be discharged at high speeds.

Wind dispersal

A method of seed dispersal utilizing lightweight fruits adapted to be carried by air currents.

Water dispersal

A method of seed dispersal using floating fruits that are carried by water currents.

Zoochory

The general term for seed dispersal by animals.

Epizoochory

Seed dispersal where seeds are transported on the outside of vertebrate animals, often with adaptations like adhesive mucus, hooks, spines, or barbs.

Endozoochory

Seed dispersal via ingestion by animals, a common mechanism for most tree species.

Explosive dehiscence

The physical action of a fruit bursting open to forcefully discharge its seeds.

Convergence of Phenotypes

The development of similar traits or forms in geographically isolated species, often due to similar environmental challenges or opportunities.

Stem succulence

An adaptation, particularly in desert plants, where stems are modified to store water.

Xerophytes

Desert plants that exhibit adaptations like succulence to store and conserve water in arid environments.

Phreatophytes

Desert plants characterized by extremely long roots that reach the water table to acquire water.

Perennials

Species that overwinter by means of special structures and come to life during favorable conditions, often year after year.

Annuals (Therophytes)

Species that germinate only during heavy rain, quickly complete their sexual life cycle, and then die.

Ubiquitous (Cosmopolitan) species

Species that are found worldwide in areas where their specific habitat exists.

Endemic species

Species with restricted geographical distributions, found only in a specific location.

Native species

Species found in a particular location because they originated there or migrated long enough ago to become established members of the local community.

Autochthonous species

Native species that originated in the region of interest.

Allochthonous species

Species that originated elsewhere and dispersed into the region of interest, also known as exotic, alien, or invasive species.

Exotic species

Species that have arrived recently in a locality, often categorized as introduced if brought by human activity.

Introduced species

Exotic species that have been brought to a locality as a result of human activity.

Invasive species

Exotic species that become permanent residents and have a significant, often detrimental, effect on the total community composition (e.g., European Starling, Purple Loosestrife).

Biogeographic Realms

The broadest biogeographic divisions of Earth's land surface, based on the distributional patterns and shared evolutionary history of terrestrial organisms, separated by geographic barriers like oceans or mountains.

Wallace's Line

A faunal boundary line drawn by Alfred Russel Wallace that separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia.

Endemism within realms

The phenomenon of species being unique to a particular biogeographic realm, resulting from evolution in relative isolation due to natural barriers.

Disjunct Distributions

A pattern of species distribution characterized by significant gaps between populations.

Relict Populations

Remnant populations that are no longer part of a larger species distribution due to the extinction of intervening populations, often representing refugia from past climate changes.

Refugia

Locations where populations of organisms can survive during periods of unfavorable environmental conditions, often representing fragments of ancestral distributions.

Extirpation

Local extinction of a species, which can transform a continuous distribution into a disjunct one or shift the center of a distribution.

Dispersal (and speciation)

The process where a few members of a species move to a new geographical area, potentially leading to new taxa through mechanisms like the Founder Effect.

Founder effect

A genetic bottleneck that occurs when a new population is established by a small number of individuals, potentially leading to speciation due to different allele frequencies.

Serial founder effect

Successive bottleneck events that occur as a population expands across new territories, often with repeated migration and settlement.

Vicariance (and speciation)

The process where a natural geographic barrier arises and separates an ancestral population, leading to genetic isolation and potential speciation.