Endemism

Some living things live in only one place.

They do not live anywhere else in the world. This can happen on a small island. It can also happen in a deep cave.

Some plants and animals live in just one part of a country.

This happens when a group is cut off from others. They might grow into a new kind of living thing. It is fun to see what lives near you!

Some living things live in only one place. We call this endemism.

An endemic species is found in just one area. This could be an island or a single country. For example, the orange-breasted sunbird lives only in South Africa.

The bicolored frog lives only in a part of India. Some species live in tiny spots, like Montezuma Well in Arizona.

How does this happen? Often, a group gets cut off from others. This is called allopatric speciation. This happens when groups are separated by land or water. They may grow into new species over time. Remote islands like Hawaii have many endemic species. This is because the animals are isolated.

Some species are paleoendemics. These are old species that used to live in many places. Now they live in only one small spot. Other species are neoendemics. These are new species that have not spread far yet. Scientists study these groups to help protect nature. It helps them know which animals might die out.

Some living things live in only one specific place on Earth. Scientists call this state endemism.

An endemic species is found in just one defined area. This area could be a single island or a whole country. For example, the orange-breasted sunbird lives only in South Africa.

The bicolored frog is found only in the Western Ghats of India. Some species live in very tiny spots. Montezuma Well in Arizona is home to at least five species found nowhere else.

This concept is very important for conservation biology. It helps experts measure biodiversity in a certain place. It also helps them see if a species might go extinct.

How does a species end up in only one place? One way is through a process called allopatric speciation. This happens when two groups of the same species are separated by geography.

They might be split by a new mountain range or a body of water. Over time, these groups change and become different species. Remote islands like Hawaii or the Galápagos often have many endemic species. This is because the animals are isolated from others. They cannot easily move to new places or meet other groups. This isolation causes them to become unique.

People have studied these patterns for a long time. The word endemic comes from the Greek word endēmos. This means "native" or "in the people."

In the English language, the word was used for diseases first. It meant a disease that stays at a steady amount in one country. In 1872, Charles Darwin used the word in biology. He used it to describe species restricted to one location. Later, in 1900, David Sharp used the term "precinctive." He used this word for insects in Hawaii. He wanted a word that did not sound like a disease.

There are different types of endemic species based on their history. Some are called paleoendemics. These are old species that used to live in many places. Now they are restricted to just one small area. The ginkgo tree is one example of a paleoendemic.

Other species are called neoendemics. These are new species that have not spread far yet. They might have just recently changed into a new kind. Scientists also look at how species move. Some plants reach islands by being carried by birds. This helps them reach places that are otherwise hard to get to.

Endemism is the opposite of having a cosmopolitan distribution. A cosmopolitan species has a very wide or global range. Most people think of endemics as being rare. However, some endemic species can actually be quite common in their one home. They are just not found anywhere else. Certain environments make endemism more likely to happen. For example, serpentine soils can act like islands. These soils have low fertility and are found in places like California or South Africa. They create special spots where unique plants grow.

Endemism describes a state where a species is found only in one specific geographic location.

This location can be quite large, like a country or a continent. It can also be very small, such as a single island or a specific sinkhole. For example, the orange-breasted sunbird lives exclusively in South Africa.

The bicolored frog is found only in the Western Ghats of India.

In Arizona, Montezuma Well contains at least five species found nowhere else on Earth. This concept is vital for conservation biology. Scientists use it to measure biodiversity in specific areas. It also helps them evaluate how much risk a species faces from extinction.

Endemism occurs through several different biological and geological processes. One major process is allopatric speciation, also known as geographic speciation. This happens when two populations of the same species become physically separated.

A mountain range or an ocean might act as a barrier between them. Once separated, these groups evolve differently over time. Eventually, they become entirely different species through reproductive isolation. This is why remote islands like Hawaii or the Galápagos Islands have high rates of endemism.

In these isolated places, organisms have little chance to receive new genes from outside groups. Other species might become endemic by using specific areas as refuges. During climate changes like ice ages, some regions remain stable. Species stay in these stable areas while dying out elsewhere.

Scientists use specialized terms to categorize species based on their evolutionary history. One important distinction is between paleoendemics and neoendemics. A paleoendemic is a species that was once widespread but is now restricted to a small area. The ginkgo tree is a famous example of a paleoendemic species. In contrast, a neoendemic is a relatively new species. These species have recently evolved and have not yet spread beyond their original range.

There are also even more specific categories. Schizoendemics arise from a wider species that becomes reproductively isolated but keeps the same chromosome count. Apoendemics are polyploids, meaning they have extra sets of chromosomes. Patroendemics have a lower chromosome count than their related polyploid ancestors. Mikio Ono also introduced the term aneuendemics in 1991 for species with unusual chromosome numbers.

Researchers also look at how species are distributed across a landscape. Some scientists use the term phylogenetic endemism to measure uniqueness. This method weights species based on how distant they are from their living relatives on the evolutionary tree. This helps capture how much unique biological history is present in an area. Some species are called holoendemics if they have stayed in a restricted area for a very long time. Others might be called pseudoendemics if they possibly evolved from a recent mutation. These different categories help experts decide how to allocate resources for protecting biodiversity hotspots.

The history of the word "endemic" provides interesting context. The term comes from the Neo-Latin and Greek word endēmos, which means "native." It is formed from the Greek words for "in" and "the people."

When it first entered the English language via French, it described diseases. It referred to diseases that stayed at a constant level in a country. In 1872, Charles Darwin began using the term in a biological sense. He used it to describe species restricted to specific locations. In 1900, David Sharp coined the term "precinctive" for insects in Hawaii. He chose this word because he felt "endemic" was too closely associated with sickness.

Endemism is the opposite of having a cosmopolitan distribution. A cosmopolitan species has a global or very widespread range. It is a common mistake to think all endemic species are rare. Some endemic species can actually be quite common within their specific home. However, they are still considered endemic because they do not exist anywhere else. Even microorganisms were once thought to be cosmopolitan. The hypothesis "everything is everywhere" suggests that organisms smaller than 2 mm are found wherever habitats support them. This theory suggests that small organisms might not follow the same rules as larger animals.

Certain environments are much more likely to produce endemic species. One such environment involves serpentine soils.

These soils have low fertility and act like "edaphic islands." They are found in places like the Balkan Peninsula, South Africa, and parts of California. Because the soil is so different, plants must adapt to it. This creates high rates of endemism. Caves also create unique conditions for species. Animals that live only in caves are called troglobites. These specialized environments provide the isolation necessary for new, unique species to develop.