Biogeography Flashcards

Flashcards about biogeography, including its definition, key figures, areas of study, and the biogeographical distribution of species, with a focus on Darwin's observations and the distribution of flightless birds.

What is biogeography?

The study of the past and present distribution of the world's many species.

What fields do biogeographers integrate information from?

Ecology, evolution, palaeontology, and climatology.

What questions do biogeographers attempt to answer?

To understand which species occur where, and how they have adapted to their surroundings.

Who was Alfred Russel Wallace?

A 19th-century British naturalist, explorer, geographer, anthropologist, and biologist who helped to found the modern science of biogeography.

What areas are studied in biogeography?

Dispersal, evolution, and extinction.

What is dispersal in the context of biogeography?

The movement of populations away from their point of origin.

What is evolution in the context of biogeography?

The change in the genetic composition of a population.

What is extinction?

The disappearance of a species.

What is plate tectonics?

The process by which rigid plates of the Earth's crust move across hot molten material.

What is the biosphere?

The whole area of Earth's surface, atmosphere, and sea that is inhabited by living organisms.

What was the single land mass called that all continents were once part of?

Pangaea.

What is continental drift?

The process of drifting apart of the continents.

What are the main biogeographical regions?

Nearctic, Neotropic, Palearctic, Afrotropic, Indomalaya, and Australasia.

Which land masses are associated with each biogeographical region?

North America, Eurasia, South America, Africa, Australasia, Indomalaya, Oceanic and Antarctic.

Why is there diversity between different biogeographical regions?

Local diversification by speciation and the dispersal of those species within a biogeographical region.

What are some examples of differences between biogeographical regions?

Different species of flightless birds, such as the ostrich, emu, and rhea.

What is a significant difference between the Australian region and other biogeographical regions in terms of mammals?

The large indigenous mammals are marsupials, while in other regions, they are placentals.

What are marsupials?

Animals who begin life in the uterus but leave to enter the marsupium or pouch while they are still an embryo.

What are placental mammals?

Animals with a placenta connecting the foetus within the uterus to the mother's circulatory system.

How did Darwin study the biogeographical patterns of existing species?

Collecting first-hand evidence in the Galapagos Islands and the plains of Patagonia.

What orthodox theory did Darwin reject?

That all species remain unchanged and that discontinuities in distribution patterns are due to separate multiple creations.

According to Darwin, how can the distribution patterns of a species be explained?

Each species having its origin in a single centre of origin, from which it dispersed.

How did separate populations evolve according to Darwin?

Populations became isolated by geographical barriers, adapted to new conditions, and formed new species.

What did Darwin observe about tortoises on the Galapagos Islands?

Island-to-island variation, with differences in shell shape and neck length.

What did Darwin observe about species in adjacent geographical areas?

Species in adjacent geographical areas tend to have more features in common than those living further apart.

What is an example of a species on the Galapagos Islands that shows slight differences between islands?

Darwin's mockingbirds.

What are the characteristics of ratites?

They resemble each other, have similar modes of life, but are clearly different species.

Where are ratites distributed?

Northern, eastern, and southern Africa; South America; Australia; and New Zealand.

What are the physical characteristics of ratites?

A flat sternum, small wings, large bodies, heavy leg bones, thick, strong feet with a specialized toe structure, and no opposable first toe.