Endemism is characterized by the restricted occurrence of a species to a specific geographical area, i.e. the species is not found naturally anywhere on planet Earth except in that area.
The different species of living beings are not scattered around the world by chance, they inhabit places where they have adapted to ecological and climatic conditions. These conditions turn out to be suitable for their survival and reproduction, forming an ecosystem with complex ecological relationships between its components. However, ecological conditions alone are not always enough for their perpetuation, as there are other factors that limit or promote the occurrence of species in the natural environment. Most living beings live in very well delimited areas and are restricted to just a small geographical area in a given municipality, city or state.
Certain species have a wider tolerance range of occurrence, so they adapt more easily and are distributed over more extensive geographical areas. Geographically isolated environments, such as islands and even valleys, mean that the species there are viewed in a very particular way, as they have an inherent vulnerability, making them an essential reference for the formulation of biodiversity conservation strategies.
Endemism is a factor resulting from the performance of isolating mechanisms, such as the unique evolution of a species; significant population reduction; physical barriers, such as the formation of mountain ranges, rivers and changes in sea levels over time, or even the formation of roads and plantations that prevent communication between individuals from two fragments of an original area - this process is called allopatry -; very specific environmental conditions and even behavioral issues, such as different breeding seasons between species. These areas, which have been geographically delimited from an ecosystem due to a common process of isolation over time, are often considered to be areas of endemism (AE).
Endemic species can be classified into several categories based on their distribution, origin, age and taxonomy. These include autochthonous species, which are native to the affected region and continue to live there, while allochthonous species do not occur naturally in the region where they have settled. There are also taxonomic species, which are the only remnants of previously diverse groups, and biogeographic species, which are endemic species descended from a group that was once widely distributed. In addition, there are neoendemic species, which have formed recently, and paleoendemic species, which were quite widespread in the past but have suffered a significant drop in population.
Two methods are commonly used to identify endemic areas in Brazil: one is to overlay maps of species with small distributions in comparison to the study area to be evaluated and within that area, there is identification by complete or almost complete agreement of the distributions of two or more species; and a method based on a Parsimony Analyses of Endemicity.
Brazilian biomes are examples of areas with a certain degree of endemism, with many species that can only be found in these places, such as the Amazona brasiliensis species (red-tailed parrot) and the Cecropia sp. tree (cecropia), which are from the Atlantic Forest biome, and also the Trichechus inunguis (Amazonian manatee) and Victoria amazonica (Amazon Giant Waterlily), which are specific to the Amazon biome, among countless other species that can be specifically observed between biomes.
Regions with high concentrations of biodiversity are, and always will be, conservation priorities. However, the lack of knowledge about species makes it difficult to identify endemic groups and areas of endemism, making conservation actions less effective. Therefore, the first step to conserving biodiversity is to study and describe it, after all, we can only protect what we know deeply.
Author: Victor Lucino - Vice President of GEAS Brazil
Proofreading: Iago Junqueira - The Wild Place Co.
June/2024 Wild Panel
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