We explain what a species is, what its origin is and its relationship with the genus. The types of species, the endangered species and examples.
What is a species?
In biology, species is understood to be the basic unit of classification of living things, that is, the bottom rung of any form of biological taxonomy. A species is a set of organisms capable of reproducing and obtaining fertile (non-hybrid) offspring, and that share its basic evolutionary defining traits.
I know currently know about 1.9 million species of living beings on our planet, spread over the various kingdoms 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 reproductively homogeneous.
The biological classification gives each species a proper name, written in Latin and consisting of two terms: first that of the genus and then that of the species, as in Homo sapiens, name of the human species. In this sense, when we use common terms to refer to certain forms of life, such as “dog”, “cat”, “fungus” or “fern”, we are actually referring to a set of species that can be extremely diverse from each other.
Origin of species
The way species appear is known thanks to the works of Charles Darwin, mainly. Your essay The origin of species published in 1859, it laid the foundation for what we know today as biological evolution. In that text, Darwin explained that the species of living beings came from other previous species, that is, from their ancestors, whose destinies had been determined by environmental pressure, that is, the competition to survive and reproduce against other contemporary species. . Darwin called this competition “natural selection.”
Thus, the species come from each other earlier, going 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 verified how the species of the Galapagos Islands were similar, but at the same time different, from those on the mainland. This suggested that, geographically isolated for a sufficient amount of time, the island species had adapted to their new environment, following a different evolutionary path from their companions on land. And so, eventually, each variant ended up being a different species.
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, gender Homo (human) and species “sapiens” (wise). This is because genus is a higher taxonomic category (more general, less specific) than species, but inferior (less general) to the family.
The gender, like this, is a lineage of species, evolutionarily related and that in some way they constitute variants, it could be said that different materializations, of a general concept that encompasses them. The genres, furthermore, can be divided into subgenres or infragenres, sort of genres-within-genre, or they can be grouped into supergenera, 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 ones are registered.
- Vegetable species. Of which 310,129 different ones are registered.
- Mushroom species. Of which there are about 120,000 different notes.
- Protist species. Of which there are 55,000 different notes.
- Bacteria species. Of which about 10,000 different ones are known.
- Archaea species. Of which only about 500 are known different ones.
- Virus species. Of which there is a record of about 3,200 different ones.
Examples of species
Some examples of species are:
- Homo neanderthaliensis. Extinct species of the human race, which coexisted 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 genetically belong, had it not been domesticated thousands of years ago.
- 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. A species of gram negative bacteria that inhabits the human gastric system, being able to develop infections in the gastric mucosa.
- Rhodniusprolixus. Called chipo or pito, it is a common blood-sucking insect in the American continent, capable of transmitting Chagas disease.
- Populus Sunrise. Known as white poplar or common poplar, it is a leafy tree with green leaves with a white underside, common in Europe and Asia, that grows up to 30 meters in height.
Native species
Native species are those that are native to the habitat in which they are foundIn other words, they do not come from migrations, nor have they been artificially introduced. However, unlike endemic species, native ones can perfectly be found in other environments, in which, logically, they will no longer be native, but rather exotic species.
For example: the marine iguana of the Galapagos Islands (Amblyrhynchuscristatus) 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 (Linepithemahumble) is a native species of South America (Argentina, Paraguay, Bolivia and southern Brazil), which has been artificially introduced to all other continents except Antarctica, and in them competes with the native ant species of said continents.
Follow in: Native species
Exotic species
Exotic species, introduced species or foreign species are those that they are not native to the place where they are found, that is, that they have been artificially introduced or that they are the result of migrations. In this sense, they are considered the opposite of native species.
Exotic species they can be beneficial or harmful to the habitat that receives them, thus altering the local ecological balance, and may result in competition for native species. In the event that they are harmful, they are considered invasive species.
Humans are responsible for many species introductions over time, either consciously (green engineering) or unintentionally. A clear example of this are cows (Bostaurus), which today are grazed throughout the world but have a South Asian origin. Another is the various species of wheat (Tricutumspp), introduced by agriculture on all continents.
Invasive species
Invasive species are considered to be those exotic species that, once arrived in a new habitat, they proliferate and cause 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 biotic level but also at the economic and agricultural level, or public health, and therefore there are international regulations regarding the control of the transit of animals, plants, seeds, etc.
An example of invasive species represents it common rabbitsOryctolaguscuniculus) introduced to Australia in the 19th century to practice the sport of hunting, and that proliferated to such a degree that they became a plague in this country, putting entire plantations in check, since they did not have natural predators in said ecosystem.
Endangered species
Extinction is the death of a species, that is to say, 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 in a massive way, in what is known as mass extinctions, evidenced in the geological fossil record.
Extinctions can occur for various reasons: drastic changes in the ecosystem (climatic, chemical, geological, cataclysms, etc.), the emergence of a new, more successful species (natural selection) or, as occurs in current times, due to human activity: pollution, hunting or indiscriminate logging, etc. .