We explain to you what a species is, what is its origin and its relationship with the genus. The types of species, the species in extinction and examples.
What is a species?
In biology, the basic unit of classification of living beings, that is, the lower rung of any form of taxonomy, is understood as a species. Biological One is a set of organisms capable of reproducing and obtaining fertile offspring (not hybrid), and sharing their basic evolutionary defining traits.
About 1.9 million species of living beings are known on our planet, spread across the various realms of life. Many of them share evolutionary origins or are evolutionarily related from some common ancestor, although the category of species is difficult to apply to primitive organisms. of non-sexual reproduction, since they are not just reproductively homogeneous.
The biological classification gives each species its own name, written in Latin and consisting of two terms : first that of the genus and then that of the species, as en Homo sapiens, name of the human species. In this sense, when we use common terms to refer to certain forms of life, such as perro, gato, hongo or fern, we are really referring to a set of species that can be extremely diverse among themselves.
See also: Community in biology.
Origin of the species
The way in which the species appear is known thanks to the works of Charles Darwin, mainly . His essay The Origin of Species published in 1859 laid the foundation for what we know today as the biological Evolution. In that text, Darwin explained that the species of living beings came from other previous species, that is, from their predecessors, whose fates had been determined by environmental pressure, that is, the competition to survive and reproduce against other contemporary species . This competition was called by Darwin "natural selection".
Thus, the species come from each other earlier, dating back in life to a common ancestor, and so on until the first forms of life. Darwin understood all this when in his travels he found how the species of the Galapagos Islands were similar, but at the same time different, from those on the mainland. This suggested that, geographically separated for a sufficient amount of time, the island species had adapted to their new environment, following an evolutionary path different from that of their mainland companions. And so, eventually, each variant ended up being a different species.
It can serve you: Evolution of Man
Species and genus
In the scientific name of the species of living beings, we can see both the genus and the species, written in Latin: Homo sapiens, genus "Homo" (human) and species "sapiens" (wise). This is because the genus is a higher taxonomic category (more general, less specific) than the species, but inferior (less general) to the family.
The genus, thus, is a lineage of species, evolutionarily related and that somehow constitute variants, it could be said that different materializations, of a general concept that encompasses them. The genders, moreover, can be divided into subgenres or infragéneros, sort of genders-within-the-genre, or can be grouped into supergenders, an intermediate link between gender and family. There may be genera of a single species.
Types of species
Species can be classified according to the realm of life to which the animals they describe belong. In that sense, we know (according to 2009 standards):
- Animal species. Of which 1, 424, 153 different are registered.
- Vegetable species. Of which 310, 129 different ones are registered.
- Mushroom species Of which there are notes of about 120, 000 different.
- Protist species. Of which there are notes of 55, 000 different.
- Bacteria species Of those known about 10, 000 different.
- Archaea species. Of those barely known about 500 different.
- Virus species. Of which there are about 3, 200 different records.
Examples of species
Some examples of species are:
- Homo neanderthaliensis. Extinct species of the human genus, which lived with modern humanity about 230, 000 years ago.
- Cannis Lupus Known as the gray wolf, it is the most common species of wildlife wolves in the world, to which the common dog could belong genetically, had it not been domesticated thousands of years ago. years.
- Panthera tigris. It is one of the four species of tigers in the world, famous for its grated and orange leather. It is endemic to the Asian continent where it is a great jungle predator.
- Helicobacter pylori. Species of gram negative bacteria that inhabit the human gastric system, and can develop infections in the gastric mucosa.
- Rhodnius prolixus. Called chipo or pito, it is a common blood-borne insect in the Americas, capable of transmitting Chagas disease.
- Populus alba. Known as the white flame or as a common flame, it is a leafy tree with green leaves with white backs, common in Europe and Asia, which grows up to 30 meters high.
Native species are those that are native to the habitat in which they are found, that is, they do not come from migrations, nor have they been artificially introduced. However, unlike endemic species, the natives can be perfectly found in other environments, in which, logically, they will no longer be native, but will be exotic species.
For example: the marine iguana of the Galapagos Islands ( Amblyrhynchus cristatus ) is native and endemic to the islands, since they originate there, and nowhere else in the world is it found . On the other hand, the Argentine ant ( Linepithema humile ) is a species native to South America (Argentina, Paraguay, Bolivia and southern Brazil), which has been artificially introduced to all other continents except the Ant rtida, and in them competes with the species of native ants of these continents.
Follow in: Native species
The exotic species, introduced species or foreign species are those that are not native to the place where they are found, that is, that have been artificially introduced or that are the result of migrations. They are considered the opposite of native species.
Exotic species can be beneficial or harmful to the habitat that receives them, thereby altering the local ecological balance, and may result in competition for native species. In case they are harmful, they are considered invasive species.
The human being is responsible for many species introductions over time, either consciously (ecological engineering) or involuntarily. A clear example of this is cows ( Bos taurus ), which are grazed around the world today but have a South Asian origin. Another is the various species of wheat ( Tricutum spp ), introduced by agriculture in all continents.
Follow in: Exotic Species
Invasive species are considered to be those exotic species that, once they reach a new habitat, proliferate and generate an alteration in the native ecosystem, displacing other species or impoverishing the ecological niche, since they come from an external biological system. These species can represent a real biological danger, not only at the biological level but also at an economic and agricultural level, or of public health, and therefore there are international regulations regarding the control of the transit of animals, plants, seeds, etc.
An example of invasive species is represented by common rabbits ( Oryctolagus cuniculus ) introduced in Australia in the 19th century to practice the sport of hunting, and that proliferated to such an extent that they became a pest in this country, putting check entire plantations, since they did not possess natural predators in that ecosystem.
Follow in: Invasive species
Extinction is the death of a species, that is, the disappearance of all the individuals that compose it. It is a process that has often occurred in the biological history of the planet, sometimes individually and sometimes massively, in what is known as mass extinctions, evidenced in the geological fossil record. Gico.
Extinctions can occur for various reasons : drastic changes in the ecosystem (climatic, chemical, geological, cataclysms, etc.), emergence of a new, more successful species (selection n natural) or, as in current times, by human activity: pollution, hunting or indiscriminate felling, etc.
Follow in: Endangered species