The scientific method of dividing organisms into large and small groups based on their similarities among themselves was proposed by the Swedish naturalist (botanist, zoologist, naturalist, medical practitioner, pathologist) Carl von Linnaeus, who in 1735 published the scientific work “The System of Life”. Although the book contained erroneous statements, it was a breakthrough in biology. Only during the life of the author, it was reprinted many times.
What did Carl Linnaeus suggest
Linnaeus is called the creator of biological language. Some techniques had been proposed by other naturalists before, but he was able to combine them into a coherent system for both animals and plants. Linnaeus suggested the following:
- Group plants and animals according to similar characteristics into several taxa with a strict hierarchy.
- Each organism is assigned a name in Latin. It consists of two parts. Genus in biology is the first word in the name.
- The youngest rank is kind. The second word in an organism's name, most often an adjective or genitive noun, is lowercase.
- Free interbreeding of individuals of the same species (i.e., the birth of fertile offspring) is a key sign of belongingmind.
- An organism can only be part of one group at each level, so it gets a strict address in the biological system, containing the exact sequence of ranks and the same binary name.
Now in biology, genus, species, class and other hierarchical levels seem familiar and even natural. But almost 3 centuries ago it was a powerful impetus to development, which was extremely hampered by the lack of hierarchy and strict nomenclature. It is in this that they see the great merit of Linnaeus, of course, not the only one.
Many tried to introduce the classification of all living things according to different criteria even before it. But, given the diversity even at that time of open and described species, it was a titanic work and at the same time an insight. After all, the signs by which systematization should have been carried out still had to be identified.
What is a genus in biology
In short, a supraspecific taxonomic unit in the biological taxonomy of living organisms. In Latin, genus is genus. Genus in biology is a singular noun in Latin. In the name of the organism, it is written with a capital letter. It is sometimes abbreviated to a capital letter with a dot. The word itself can be both the surname of the naturalist who first discovered and described the species, and a noun borrowed from another language.
What is a genus in biology is quite difficult to say, in terms of exactly what features it combines species. In general, they are similar in origin. That is, the remains of ancestors are known and found. Extinct species also have a strictplace in the hierarchical system. So, a genus in biology is a concept similar to that in genealogy: representatives of a family whose ancestor was a common ancestor, for example, the Romanov dynasty.
It is much easier to describe the unifying features, for example, for the class mammals or the order carnivores. Everything is clear from the name of the taxon.
Do representatives of the same genus interbreed
A genus in biology is the penultimate rank, so the question of whether it is possible for members of the same genus to have offspring is logical. But from the point of view of evolution, the point is not whether mating is possible, but whether the couple will have fertile offspring? And is the endless mixing of species necessary?
When interspecific crossing most often the offspring is barren. According to Haldane's rule, a hybrid of the heterogametic sex is more often unviable and sterile, carrying XY chromosomes not only in humans, but also in mammals in general. This is a male, male. Such destruction of hybrids is the natural protection of individual species from mixing.
Besides this, there is a natural geographical protection - representatives of different species of the same genus do not live in the same area. For example, lions live in Africa, and tigers live in Asia. Their hybrid was born in a zoo, because in the natural environment it is impossible to meet.
Liger is a huge descendant of a lion (Panthera leo) and a tigress (Panthera tigris). It is sandy in color, but with indistinct stripes. Born by crossing two species of the same genus of panther in the cat family, with the lion being the male and the tiger being the female. In the photo, the largest of the ligers is Hercules. According to the ruleHaldane, their females are fertile and males are sterile.
Generations are combined into families
Family - the next rank, which combines several genera. If you go down the taxonomic system of biology from classes to species (family, genus and species), each rank becomes more numerous.
How are they designated? Most often, the name of the family is derived from the genus that is the most typical of all in the taxon. The ending -idae in zoology or -aceae in botany is added to the root of the noun. For example, the cat family (Felidae) was given the name of the cat genus (Felis) in its composition, and in the first photo of the article, representatives of the genus Primula (Primula) of the Primulaceae family.
Example
In the photo, the location of the brown bear Ursus arctos in the biological system: Kingdom - Animals, Type - Chordates, Class - Mammals, Order - Carnivores, Family - Bears, Genus - Bears, Species - Brown Bear.
The higher you move from species to higher ranks, the more unexpected "distant relatives" appear in a bear. But, according to the theory of evolution, they were all once united by a common ancestor.
