Biogeography is the science that figures out how species are distributed from a local to global scale. Before The Theory of Island Biogeography, by E.O Wilson and Robert MacArthur in 1967, it was seen as a historical one. Biogeography mainly focused on observing and reporting on in detail. MacArthur and Wilson changed this perception, and showed how useful data and information can better help explain why certain species are someplace, and others are not.

The origins of biogeography go back to the early to mid-19^th century. Natural historians made lists of known animals and species throughout the world. The information was then published in several books by authors Alexander von Humboldt, Hewett Watson, Alphonse Candolle, Alfred Russel Wallace, and Charles Darwin. The "revolution" in biogeography didn't really start until Charles Darwin and Alfred Russel Wallace. The two would create the idea of evolution by natural selection.

Evolution means that species adapt over time to their surroundings. Natural selection means that some species are better equipped at living than other. Darwin and Wallace said the key to understanding geographical distribution was evolution. An example of this would be white vs brown rabbits. If they're in an environment that snows, the white rabbits will live far better than the brown, until eventually either the brown turn to white or the brown die out. This is called "survival of the fittest", and "speciation".

Speciation is when a new species comes about from the original species and becomes two different kinds of a creature. Time and place usually cause this. Times when species might not be able to move are when there are obstacles (mountains, water bodies, rough terrain, etc.) that get in the way from it progressing to a point where it would flourish.

Charles Darwin focused on islands, most famously the Galapagos Islands, while Wallace preferred to study flora and fauna in the Amazon Basin and Malay Archipelago. Both made note that islands were the best example of evolution, as species would adapt and grow solely based on what is on the island

Some animals never leave their area, one of the prime examples being the Australian marsupials. Birds and insects can travel by flight so they have a very easy time moving from area to area. Fish also have the capacity to swim great distances, traveling anywhere in the ocean, up rivers, and in vast lakes. There are exceptions to fish, since there is a separation in fish on either side of America, and fresh water fish do not disperse as much.

The Human Genome Project broke down human DNA to better understand our origins and what composes our DNA. This same process is being applied in biogeography, where they're using DNA samples to test where animals originated from and how differently they evolved from creatures from previous speciation.

Biogeography is an incredibly deep and rich study that shows how little we know about the animals on our planet. As we get more knowledge on the subject, we will be able to know the origins of humanity, as well as where human evolution will take us next.

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