6. What Does Endemic Mean? -
Endemic species have been the focus of scientific research for many centuries. Botanists, zoologists, and natural historians have all been captivated by the rarest and most unique plant and animal species and their habitats all over the world. But what are endemic species? Endemism occurs when a plant or animal species can only survive in a specific geographic location and cannot be found in any other place on Earth. Endemic is the word used to describe the organism. The region where these unique species live is further defined by one of 3 terms: 1) Site endemic, meaning the species occurs within a small range (only on Mt. Hood, for example); 2) National endemic, meaning the species is found within one nation (only in Mexico, for example); and 3) Geographical range endemic, meaning the species thrives throughout a specific geographic area that may spread over several countries (the Andes mountains, for example).
5. Factors Influencing High Rates Of Endemism -
Isolation is one of the principal factors leading to endemism. In remote areas of the world, external influences have not been able to shape the evolution and adaptation of plant and animal species. These organisms, then, evolve only to their very limited surroundings. They have not been exposed to diseases of the outside world, geographic changes, or environmental disturbances. Islands are an excellent example and are often cited as having high levels of endemism. Again, this is due to their isolation from other parts of the world. Island habitats are typically small with significant habitat and climatic diversity, making them the perfect environment for endemic species to occur. Additionally, the older the island is, the more likely it carries high numbers of endemic species.
Islands are not the only isolated geographic regions, however. Remote habitats can also occur on mainlands within different types of ecosystems. For example, lakes located far from other bodies of water or valleys surrounded by high, impassable mountains also rank high in endemism. In places where a catastrophic event has occurred within the last ten thousand years or so, endemic species are not common. This is the case in Canada, which was covered by ice until about 11,000 years ago. Endemism has not had sufficient time to evolve and therefore endemic species are rare in Canada.
4. Hotspots Of Endemism In The World -
Generally speaking, there is a significant overlap between the world’s biodiversity hotspots and its endemic hotspots. This is because biodiversity hotspots are defined by those areas that have greater than 1,500 endemic fauna and that have lost over 70% of its original plant life due to habitat degradation. In fact, of the 20 regions with the highest rates of endemism, 16 are also considered biodiversity hotspots. As previously mentioned, islands have high rates of endemism and comprise half of the 20 regions. It comes as no surprise, then, that many of the endemic hotspots in the world are places like the US state of Hawaii, Madagascar, the Philippines, Atlantic Islands, Taiwan, New Guinea, Galapagos Islands, and New Caledonia. In Hawaii, for example, 2,000 species of angiosperm plants can be found. Of these, 94% to 98% are endemic. Something similar is seen on New Caledonia, where 76% of all plant species are endemic. Australia, China, Ecuador, India, and Mexico not only are considered megadiverse countries, but also have high levels of endemism.
3. Endemism And Evolution -
As previously mentioned, endemic species evolve in isolated conditions. This means they did not have much competition among similar species and in some cases, this lack of competition promoted symbiotic relationships between organisms. Symbiotic relationships occur when different species rely only on each other for survival. Evolutionary radiation, when organisms rapidly evolve from a common ancestor into a wide variety of new species, is also more likely in isolated regions. This is because the lack of competition among other species leaves niches in the ecosystem to be filled. An extreme number of species evolve, adapting to a very specific habitat and developing very specific survival requirements. Evolutionary radiation is seen in the 13 species of finches on the Galapagos Islands and the 1,250 species of fruit flies on the Hawaiian Islands.
Researchers often consider endemism hotspots to be windows into evolution, allowing for in-depth study, hypotheses, and observations. These regions are where the mysteries of evolution and nature can be solved, or at least better understood. Because the endemic wildlife in these areas is often simpler than that found on large continents, they make it easier for scientists to understand their evolutionary progression.
2. Why Are Endemic Species Easily Vulnerable To Threats? -
Endemic species are vulnerable to threats because they can only survive in a very limited range. The very habitat that keeps them alive restricts them from survival. When their habitats are threatened by global climate change, human alterations, and degradation, the endemic species have nowhere else to go. Because they have not evolved to survive in various ecosystems and because they require very specific surrounds for their survival, these threats carry an even greater risk of extinction than they might in larger, less endemic regions. Some of the most common threats to regional endemism include agriculture, urbanization, mining, and logging. These activities all result in habitat degradation caused by deforestation, pollution, and the introduction of invasive species. These changes are detrimental to endemic species. For example, approximately 75% of the species that have gone extinct over the last few hundred years were endemic.
1. Importance Of Conservation Of Endemic Species -
Conservation is important in order to prevent global loss of biodiversity. When one species becomes threatened or goes extinct, the effect is widespread. Sometimes, it is only one endemic species that fills a need within an ecosystem; when that need is left unfilled, a chain reaction of events occurs leading to continued biodiversity loss. Estimates suggest that when one endemic plant species goes extinct, between 10 and 30 additional animal species become extinct. Therefore, the conservation of endemic species, in particular, is important.
Biodiversity is the foundation of healthy global ecosystems, in turn, healthy ecosystems sustain life, including human life. Without biodiversity, and specifically endemic species, the earth would no longer be able to produce sufficient amounts of our most basic necessities: food, water, and air. This is why biodiversity conservation efforts should focus principally on endemic plant and animal species. Unless drastic measures are taken quickly, these species and their unique habitats will continue to decline and disappear.