Case Studies of Biogeographic Patterns and Processes

Vicariance is the process by which a population is divided into two or more geographically isolated populations. The breakup of Pangea is an example of a vicariance event because it resulted in the isolation of many different groups of organisms.

Dispersal is the process by which organisms move from one place to another. The colonization of the Hawaiian Islands is an example of a dispersal event because it involved the movement of organisms from one place (the mainland) to another (the islands).

Adaptive radiation is the process by which a group of organisms evolves into a variety of different forms, each of which is adapted to a different environment. The evolution of different species of finches on the Galapagos Islands is an example of adaptive radiation because the different species are adapted to different food sources.

Convergent evolution is the process by which different groups of organisms evolve similar traits in response to similar environmental pressures. The evolution of wings in birds and bats is an example of convergent evolution because both groups of organisms have evolved wings in order to fly.

Coevolution is the process by which two or more species evolve in response to each other. The relationship between flowers and pollinators is an example of coevolution because the flowers have evolved to attract pollinators, and the pollinators have evolved to feed on the flowers.

A keystone species is a species that has a disproportionately large impact on its ecosystem relative to its abundance. The sea otter is an example of a keystone species because it preys on sea urchins, which helps to keep kelp forests healthy. Kelp forests provide food and habitat for a variety of other marine organisms.

A threatened ecosystem is an ecosystem that is at risk of being destroyed or degraded. The Amazon rainforest is an example of a threatened ecosystem because it is being cleared for logging, agriculture, and mining.

A conservation success story is a case where a species or ecosystem has been successfully protected or restored. The recovery of the bald eagle is an example of a conservation success story because the bald eagle population has rebounded from near extinction to become a common sight in many parts of North America.

A biogeographic region is a region of the Earth that is characterized by a distinct set of plants and animals. The Nearctic is an example of a biogeographic region because it includes North America and Central America.

A biodiversity hotspot is a region of the Earth that is home to a large number of endemic species. The Amazon rainforest is an example of a biodiversity hotspot because it is home to over 10% of the world's known species.

A conservation easement is a legal agreement that restricts the use of land in order to protect its natural resources. Conservation easements are often used to protect forests, wetlands, and other sensitive habitats.

A land trust is a non-profit organization that works to protect land by acquiring it or by working with landowners to place conservation easements on their land.

A green infrastructure project is a project that uses natural systems to manage environmental problems. An example of a green infrastructure project is a project that uses rain gardens and bioswales to manage stormwater runoff.

Sustainable development is a type of development that meets the needs of the present without compromising the ability of future generations to meet their own needs. An example of a sustainable development project is a project that builds affordable housing while also protecting the environment.

A climate change adaptation project is a project that helps people to adapt to the impacts of climate change. An example of a climate change adaptation project is a project that builds seawalls to protect coastal communities from sea level rise.