36 Examples of Biogeography in Real Life

Biogeography, a multidisciplinary field at the nexus of biology and geography, delves into the distribution of species and ecosystems across geographic space and time. Rooted in both evolutionary biology and earth science, it seeks to explain the intricate patterns of life we observe, from the distinct flora and fauna on remote islands to the vast expanse of tundras and deserts. The Earth’s geological history, climatic changes, and ecological interactions sculpt these distributions, leading to phenomena like continental drift-induced speciation or adaptive radiations on isolated landmasses. Additionally, in our ever-globalizing world, understanding biogeography is crucial as human influences disrupt natural habitats and introduce species to new regions. This study offers invaluable insights, enabling better conservation efforts, predicting climate change impacts, and understanding the deep historical ties that bind life to our dynamic planet.

What is Biogeography?

Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. It combines elements from both the biological sciences (like biology and ecology) and the physical sciences (like geology and climatology). Biogeographers seek to understand the factors that determine where species live, how they spread, and why certain species are found in some places but not in others. Some of the factors that influence these distributions include plate tectonics, climate, topography, soil, and human influence.

There are several key concepts and areas of focus within biogeography, including:

1. Endemism

A species is said to be endemic to a location if it is found nowhere else in the world. For example, many species in Madagascar are endemic because they do not occur anywhere else on Earth.

2. Disjunction

This refers to two or more groups that are related but are widely separated from each other geographically.

3. Migration

The movement of species from one region to another.

4. Extinction

The disappearance of species, which can have a significant effect on the distribution of other species.

5. Plate Tectonics

The movement of Earth’s crustal plates has led to the break-up and reformation of continents, influencing the spread and evolution of species.

6. Island Biogeography

A subset of biogeography focusing on the unique species distributions and ecological dynamics observed on islands. The theory of island biogeography, proposed by Robert MacArthur and E. O. Wilson, posits that the number of species found on an undisturbed island is determined by a balance between immigration and extinction rates.

Biogeography is crucial for understanding biodiversity patterns and has important implications for conservation biology, especially in the context of habitat loss, climate change, and other global changes affecting species distributions.

Types of Biogeography

Biogeography is a multifaceted field of study, and over time, several sub-disciplines or types of biogeography have emerged, each with its focus and methodologies. Here are some of the primary types:

1. Historical Biogeography

This sub-discipline focuses on understanding the historical factors that have influenced the present-day distribution of species. It often takes into account events such as continental drift, vicariance (geographical separation of populations), and dispersal mechanisms.

2. Ecological Biogeography

This branch studies the ecological factors that influence the distribution and abundance of species in the present. Factors like climate, soil type, and interactions with other organisms (like competition and predation) are central to this approach.

3. Phylogeography

This is a relatively newer sub-discipline that combines principles of biogeography and molecular genetics. It uses genetic data to understand the history and distribution of populations, tracing their evolutionary histories and migration paths.

4. Zoogeography

This specifically deals with the geographical distribution of animals.

5. Phytogeography (or Botanical Biogeography)

This focuses on the distribution of plants.

6. Marine Biogeography

As the name suggests, this type concentrates on the distribution of species in the marine environment.

7. Island Biogeography

This studies the ecological and evolutionary processes shaping the diversity of species on islands. It’s particularly concerned with the factors affecting species richness on islands, such as the size of the island and its distance from the mainland.

8. Paleobiogeography

This focuses on the distribution of ancient and extinct organisms, drawing heavily from the fossil record to infer past distributions and migrations.

9. Cultural or Anthropogenic Biogeography

Examines the impact of human activities and culture on the distribution of species. With the rise of the Anthropocene era, where human influence has become a primary driver of ecological change, this sub-discipline has gained significance.

10. Conservation Biogeography

This integrates the principles of biogeography with conservation science. It uses biogeographical techniques and concepts to address and understand conservation challenges and find solutions.

Each type of biogeography utilizes various methodologies, from GIS (Geographical Information Systems) and remote sensing to molecular genetics and traditional fieldwork, to address specific questions and challenges.

How Does Biogeography Support Evolution?

Biogeography provides strong empirical evidence for evolution by examining the distribution of species across geographical space and through geological time. Here’s how biogeography supports the concept of evolution:

1. Endemism and Island Evolution

Islands, particularly remote ones, often house species that are found nowhere else on Earth. This suggests that species can evolve in isolation and develop unique adaptations. For example, many of the species on the Galápagos Islands, which played a pivotal role in Charles Darwin’s development of the theory of evolution by natural selection, are unique to those islands.

2. Patterns of Distribution

Evolutionary theory posits that you should find related species near each other unless there’s a good reason they’ve become separated. For instance, marsupials are largely limited to Australia, a pattern best explained by their evolution in relative isolation on that continent.

3. Continental Drift and Ancient Distributions

The theory of plate tectonics and the movement of continents can be linked to evolutionary patterns. For example, similar or related fossil species are found on continents that were once connected but have since drifted apart, such as South America and Africa.

4. Adaptive Radiation

When a single ancestral species enters an environment with varied habitats and niches, it can diversify into multiple species, each adapted to a specific niche. This phenomenon, seen in places like the Hawaiian Islands and the Galápagos, offers strong evidence for evolution in action.

5. Phylogeography

This discipline combines genetic information with species’ current and historical distributions. Phylogeographic patterns often show that geographically isolated populations exhibit genetic divergence, indicative of evolutionary processes at work.

6. Mismatched Habitats and Relict Populations

Some species are found in habitats that seem mismatched to their apparent ecological preferences, but which make sense when considering historical climates and geographies. These “relict” populations suggest species’ distributions have shifted over time, influenced by climatic, geological, and evolutionary factors.

7. Convergent Evolution in Similar Habitats

Distantly related species in similar environments often evolve similar traits, demonstrating the consistent influence of natural selection. For example, the similar body forms of dolphins (mammals) and ichthyosaurs (extinct reptiles) evolved independently due to their shared aquatic environments.

8. Absence in Suitable Habitats

Sometimes a habitat might seem suitable for a species, but the species is absent because it hasn’t been able to reach that location or was outcompeted by another species that got there first. This pattern suggests that history, chance events, and evolution play roles in shaping species distributions.

In summary, the geographical distribution of species, both in the present day and in the fossil record, aligns with and supports the predictions of evolutionary theory. The patterns observed make sense when considering processes like natural selection, speciation, migration, and extinction.

Biogeography and Biodiversity

Biogeography and biodiversity are interconnected concepts within the realm of ecology and evolutionary biology. Here’s how they relate and influence one another:

1. Definition

• • Biogeography

The study of the distribution of species and ecosystems across geographical spaces and through geological time.

• • Biodiversity

Refers to the variety of life in a particular habitat or ecosystem. It encompasses the variability among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems, as well as the ecological complexes of which they are a part.

2. Influence of Biogeography on Biodiversity

• • Island Biogeography

Robert MacArthur and E.O. Wilson’s theory of island biogeography suggests that the biodiversity of an island is determined by its size and its distance from the mainland. Larger islands and those closer to the mainland tend to have higher biodiversity.

• • Historical Events

Biogeographical events like continental drift can influence biodiversity. For instance, the splitting of Gondwana led to isolated land masses like South America, Africa, and Australia, which in turn influenced the evolution and diversity of species on those continents.

• • Barriers

Physical barriers such as mountains, oceans, and deserts can prevent species from migrating, leading to different evolutionary paths and thus contributing to regional biodiversity.

3. Biodiversity as Evidence for Biogeographical Patterns

• • Endemism

Areas of high endemism (species found nowhere else) like Madagascar or the Hawaiian Islands are crucial biogeographical regions because their unique biodiversity offers insights into evolutionary processes that occur in isolation.

• • Convergent Evolution

In biogeography, similar habitats in different parts of the world may house species that, while not closely related, have similar adaptations due to facing similar environmental pressures. This can be seen in the cacti of the Americas and the euphorbs of Africa.

4. Human Influence

• • Anthropogenic Biogeography

Humans have a profound impact on both biogeography and biodiversity. Activities like deforestation, urbanization, and agriculture alter the natural distribution of species and ecosystems. Additionally, the introduction or removal of species can dramatically influence local biodiversity.

• • Conservation Biogeography

Understanding biogeographical principles is crucial for conservation efforts. Identifying areas of high biodiversity, understanding migration corridors, and recognizing regions of endemism can aid in making informed conservation decisions.

5. Climate and Biogeographical Distribution

• • Climate plays a crucial role in determining the distribution of species, which in turn influences regional biodiversity. Changes in climate can shift these distributions, leading to changes in local biodiversity.

Examples of Biogeography in Real Life

1. Island Biogeography

The theory of island biogeography, proposed by Robert MacArthur and E.O. Wilson, postulates that the number of species on an island tends toward an equilibrium that balances immigration rates of new species and extinction rates of established ones. The Galápagos Islands are a famous example where finches evolved different beak shapes on different islands due to variations in available food sources.

2. Wallace Line

Alfred Russel Wallace noted a significant faunal boundary line in the Indonesian region that separates the distribution of Asian and Australian fauna. This line, now called the Wallace Line, is believed to be the consequence of deep water straits limiting the movement and intermixing of species.

3. Continental Drift and Gondwana

Ancient supercontinents like Pangaea and Gondwana broke apart over millions of years. As these landmasses separated, species that once lived in connected environments found themselves in differing climates, leading to speciation. The similarity between the flora and fauna of South America, Africa, Antarctica, Australia, and India can be traced back to their shared Gondwanan heritage.

4. Mountain Ranges and Altitudinal Zonation

Different elevations on mountains present different climates and habitats. The distribution of species along a mountain, such as in the Andes or Himalayas, often mirrors the distribution of species at different latitudes.

5. Desert Formation and Distribution

Deserts like the Sahara, Sonoran, and Atacama are found in specific regions due to the rain shadow effect, ocean currents, and other climatic conditions. The organisms that reside in these areas have evolved specific adaptations to survive in arid conditions.

6. Glacial Refugia

During the ice ages, many regions became inhospitably cold. Some species retreated to pockets of milder climates called refugia. As glaciers receded, these species expanded their range again. The patterns of distribution seen in European trees, for instance, can be traced back to their refugia during the last ice age.

7. Barriers and Boundaries

The Great American Biotic Interchange was an event signified by the mingling of North and South American faunas following the formation of the Isthmus of Panama. Before this land bridge formed, these continents had vastly different species.

8. Human Impact on Biogeography

The introduction (both intentional and accidental) of species to new areas by humans can have dramatic effects on local ecosystems. For instance, the introduction of the cane toad to Australia has led to significant ecological disruptions.

9. Marine Biogeography

 

Coral reefs, like the Great Barrier Reef in Australia, showcase a unique biogeographic pattern. The species of corals and fish are determined by various factors including water temperature, salinity, and ocean currents.

10. Microbial Biogeography

Even microorganisms exhibit biogeographical patterns. Certain bacteria are found in specific regions, influenced by factors like pH, temperature, and other environmental factors.

11. Antarctic Biogeography

The extreme cold of Antarctica supports a unique ecosystem. While no land mammals or reptiles live on the continent, various penguins, seals, and numerous invertebrates have adapted to its icy environment. The isolation of Antarctica has led to the evolution of species found nowhere else.

12. Bering Land Bridge

Once connecting Asia and North America, this land bridge allowed for the migration of animals and humans. As it submerged due to rising sea levels, species distributions were impacted.

13. Sky Islands

In southwestern USA and northwestern Mexico, mountain ranges act as “islands” in a “sea” of desert. The higher elevations of these mountains have cooler and moister climates than the surrounding deserts, creating isolated habitats that support distinct communities, often with endemic species.

14. Tethys Sea Legacy

The Tethys Sea existed between the continents of Gondwana and Laurasia before they merged to form the current continents. The Mediterranean region’s flora and fauna are influenced by its history as part of this ancient sea.

15. Madagascar’s Unique Biota

Due to its long isolation from other land masses, Madagascar has a highly unique set of species with about 90% of its wildlife found nowhere else on Earth. This includes lemurs, baobabs, and many types of chameleons.

16. Biodiversity Hotspots

Certain regions like the Cape Floristic Region in South Africa have exceptionally high numbers of endemic species. Understanding why some areas have higher endemism than others is a key question in biogeography.

17. Alpine Flora and Endemism

Mountain tops in different parts of the world, despite being geographically distant, often have similar conditions (cold, windy, rocky) and, thus, may have similar types of adapted plants, an instance of convergent evolution.

18. Riparian Zones in Deserts

Along rivers and streams in desert areas, there are unique strips of vegetation (riparian zones) that contrast sharply with the surrounding arid landscape, supporting species that can’t survive just a few meters away in the drier desert.

19. Distributions of Seagrasses

Seagrasses are marine plants found in shallow coastal waters. Their distribution is influenced by factors like water clarity, salinity, and temperature. Studying their biogeography gives insights into coastal marine ecology.

20. Biogeography of the Deep Sea

The deep-sea environment, though less explored, has its own biogeographic patterns. Hydrothermal vent communities, for instance, are oases of life in the deep ocean and have unique organisms like giant tube worms and vent crabs.

21. Cave Biogeography

Caves often house unique organisms that have evolved in complete darkness. These species are often blind and lack pigmentation. The study of these isolated, underground habitats and their inhabitants offers insights into evolutionary adaptation and speciation.

22. Zoogeographical Regions

Earth’s landmasses are divided into zoogeographical regions or realms based on distinct animal life. For example, the Nearctic region covers North America and has distinct fauna compared to the Palearctic region which covers Europe and Asia.

23. Monsoon Forests in Southeast Asia

The seasonally dry tropical forests of Southeast Asia house a distinct set of organisms adapted to the wet and dry cycles of the monsoon.

24. Boreal Forests and Taiga

Spanning across Canada, Russia, and Scandinavia, these are the largest terrestrial biome and support species like the Siberian tiger, lynx, and various boreal birds.

25. Polynesian Migration and Dispersal

As ancient Polynesians settled the vast expanse of the Pacific, they brought with them certain plants and animals, influencing the biogeography of Pacific islands.

26. The Sahara Desert and its Oases

Oases in the Sahara act as islands of life, with distinct flora and fauna in the middle of a vast desert. The migration patterns of several birds and desert mammals are also dictated by the Sahara.

27. Himalayan Diversity

The gradients of the Himalayas, from subtropical forests at its base to alpine meadows and then to arctic conditions at its highest altitudes, display a wide range of biodiversity.

28. Biogeography of Volcanic Islands

Newly formed volcanic islands, like Surtsey in Iceland, offer a unique opportunity to study the sequence and patterns of colonization by plants and animals.

29. Mangrove Distribution

Mangroves are salt-tolerant trees that grow in coastal saline waters. The distribution of different mangrove species is influenced by factors like salinity, tidal patterns, and sedimentation.

30. Fynbos of South Africa

This unique type of vegetation is found only in the Cape Floristic Region of South Africa and is characterized by a high degree of endemism, with many plants adapted to fire and poor soil conditions.

31. Biogeography of Lakes

Each large lake, be it Lake Victoria, Lake Baikal, or the North American Great Lakes, has its own unique set of species adapted to its specific conditions.

32. Pantanal and Wetland Biogeography

The Pantanal in South America is the world’s largest tropical wetland area. It’s a haven for a rich diversity of plants and animals, especially bird species.

33. Disjunct Distributions

Some species or related species groups are found in widely separated areas with vast distances or barriers between them. Examples include certain plant species found only in eastern Asia and eastern North America, indicating ancient connections and shared ancestry.

34. Biogeography of Microclimates

Within larger climatic zones, small areas can have their own unique climates due to factors like wind patterns, shade, or soil type. For example, north-facing slopes in the Northern Hemisphere might be cooler and moister than south-facing ones.

35. Steppes and Prairies

The grassland biomes of the central United States (prairies) and central Eurasia (steppes) share many similarities in terms of their vegetation and adaptation to fire and grazing, but they host different species of fauna.

36. The Distribution of Coral Species

Different coral species have varying temperature tolerances which affect their distribution, especially in the context of global warming and changing ocean temperatures.

Summary

Here’s a summary table of all the biogeography examples cited:

#	Example Name	Brief Description
1	Island Biogeography	Evolution on isolated islands (e.g., Galápagos finches).
2	Wallace Line	Boundary in Indonesia distinguishing Asian from Australian fauna.
3	Continental Drift	Speciation from continents drifting (e.g., breakup of Gondwana).
4	Altitudinal Zonation	Species distribution at different mountain elevations.
5	Desert Formation	Deserts’ species adapted to specific climatic conditions (e.g., Sahara).
6	Glacial Refugia	Species’ retreat and expansion due to ice age glacial movements.
7	Barriers and Boundaries	Species mingling from new land connections (e.g., Isthmus of Panama).
8	Human Impact	Introduced species by humans disrupt ecosystems (e.g., cane toad in Australia).
9	Marine Biogeography	Coral reefs’ species distribution.
10	Microbial Biogeography	Microorganisms’ distribution based on environmental factors.
11	Antarctic Biogeography	Unique species adapted to Antarctica’s extreme cold.
12	Bering Land Bridge	Migration route connecting Asia and North America.
13	Sky Islands	Mountain ranges in deserts acting as isolated habitats.
14	Tethys Sea Legacy	Mediterranean region’s flora and fauna influenced by ancient sea.
15	Madagascar’s Unique Biota	Unique species due to long isolation (e.g., lemurs).
16	Biodiversity Hotspots	Regions with exceptionally high numbers of endemic species.
17	Alpine Flora and Endemism	Plants adapted to mountain tops’ similar conditions worldwide.
18	Riparian Zones in Deserts	Unique vegetation along rivers and streams in desert areas.
19	Biogeography of the Deep Sea	Unique organisms in deep-sea environments (e.g., hydrothermal vent communities).
20	Cave Biogeography	Organisms adapted to live in complete darkness in caves.
21	Zoogeographical Regions	Earth divided based on distinct animal life (e.g., Nearctic and Palearctic).
22	Monsoon Forests	Species adapted to wet and dry cycles of the monsoon in Southeast Asia.
23	Boreal Forests and Taiga	Largest terrestrial biome spanning Canada, Russia, and Scandinavia.
24	Polynesian Migration	Ancient Polynesians influenced the biogeography of Pacific islands.
25	Sahara Desert and its Oases	Oases acting as islands of life in the vast Sahara.
26	Himalayan Diversity	Biodiversity gradients from the base to the peak of the Himalayas.
27	Volcanic Islands	Colonization patterns on newly formed volcanic islands.
28	Mangrove Distribution	Salt-tolerant trees in coastal saline waters.
29	Fynbos of South Africa	Unique vegetation in the Cape Floristic Region.
30	Biogeography of Lakes	Each large lake has its own set of species.
31	Pantanal and Wetland	The world’s largest tropical wetland area in South America.
32	Disjunct Distributions	Species found in widely separated areas due to ancient connections.
33	Biogeography of Microclimates	Small areas with unique climates within larger zones.
34	Steppes and Prairies	Grassland biomes with distinct fauna in the U.S. and Eurasia.
35	Distribution of Coral Species	Coral species’ distribution affected by water temperature.
36	Fynbos of South Africa	Vegetation type unique to a specific region in South Africa.

Conclusion

Biogeography, as the intricate interplay between geography and the biological world, offers profound insights into the past, present, and potential future distributions of life on Earth. From isolated islands to vast deserts, and from the depths of oceans to high mountain peaks, the spatial patterns of species distribution reflect millennia of evolutionary history, geological shifts, climatic variations, and, more recently, human influences. As we understand these patterns, we gain not only an appreciation for nature’s richness but also the tools to address pressing concerns such as biodiversity loss, invasive species, and the impacts of climate change. By integrating knowledge from diverse examples across the globe, biogeography underscores the interconnectedness of life and provides a compass for conservation and sustainable coexistence. The study of life’s distribution is not just a scientific endeavor; it’s a narrative of our planet’s ever-evolving tapestry of life.