Modern biology, considering the methods of classifying life on our planet, uses several fundamental terms, one of which is species. This organizational form is no less important than a cell, an organism, a biocenosis. At the same time, scientists pay special attention to the process of recognizing a partner of their kind. It is known that within a species individuals have genetic similarities, while crossing other species are avoided. Also, individuals are characterized by a similar morphology, ethology, behavior, origin.
Science and life
Biology is a unique science that explains, structures into zones, seeks out patterns and connections between the most diverse forms of life that have arisen on our planet over the long time of its existence. Biology studies close species and life forms very far from each other, deals with the most diverse aspects and features of the space surrounding us. Of course, special attention is paid to the reproductive mechanisms, thanks to which organic life on the planet is maintained, supported.
Particular attention is paid to a number of biological disciplines of animal habits, since observation of them allows us to derive patterns that are valid, including for understanding the basics of human behavior. Also, the study of behaviors in the animal world makes it possible to formulate forecasts for the development of one or another species: is it not threatened with extinction, is it likely that this form of life will dominate in some space.
Biology: species as the basis for systematization
In modern science, a species is usually called a biological unit that exists over an extended time period. First, the species appears, then it is flourishing, actively spreading to territories suitable for its conditions, after which the animal behavior remains unchanged for a long time. This stage is called sustainable. External conditions change, and the behavior of animals in some cases adapts to them. If this does not happen, then the life form is considered relict. It is impossible to predict in advance the fate of any of the currently existing species. Some completely exhaust themselves, die out after years, decades, centuries. There are also those who undergo certain changes, dying out as a species, but leaving behind numerous branches from which new species originate. They may be characterized by similarities in behavior with their ancestors, but not always.
For the classification adopted in the modern scientific community, it is the species that is the main category. This is a dachshund (taxonomic unit), which occupies a hierarchical position between a subgenus and a subspecies. The term was first applied in England in the seventeenth century. Then it was suggested that different species be called different external forms with different nature, not occurring from each other.
Linnaeus: contribution to classification
The most important theoretical basis for determining the ethological criteria of a species was laid in his works by Karl Linney. It was he who put forward the ideas on which the systematics of fauna and flora, adopted today, are based. At the same time, binary nomenclature was invented, suggesting at first attribution to the genus, and then to the species.
According to the current classification system, gender is designated as a noun, type is an adjective. After indicating these two words, it is also abbreviated to indicate which scientist made the proposal for a similar name. So, the official name of the wolf is Canis lupus L. The last letter means that such a name was proposed by Linnaeus, since it was he who was the first to describe the species in detail. Then the assumption was made that the species is not characterized by strong changes over the course of the species. Linnaeus argued that the number of species was constant. This is largely based on Darwinian theory, in which speciation was the center of evolution.
Ethological criterion of the species
The species is formed by a finite number of individuals. Their behavior (as a rule) has similar features. These are the so-called ethological criteria of the species, according to which this structural biological unit can be characterized. In addition to ethological ones, there are some other criteria that make it possible to identify the species: morphology, ecology, and a number of others.
If we compare close, similar species, analyzing the ethological criterion of the species, then, first of all, the difference will be noticeable during the mating period. So, for example, there are Far Eastern zuiks. During mating games, in one of the species of these animals, the male twitches its tail twice when it looks like a female, but three times in a similar species. If some individual makes one unnecessary movement inside the family, then the female will simply not let him in. In addition, there are other differences. Mating games for many animals are a period when they make quite specific sounds. They are also characteristic for different genera different. This is another ethological criterion for the species. However, at present it is impossible to classify organisms into species, evaluating only this parameter - it lacks universality.
Terminology: population
This term refers to the totality of living organisms that live in a strictly defined territory. Usually they share the same genetic material. The genes of a population in science are called the gene pool. The new generation is always the source of certain failures, new data, to a greater or lesser extent reflected in the gene pool. The organisms that make up the population are heterogeneous, which makes it possible to work the laws of natural selection. A population within the framework of modern biology is the smallest unit of evolution. It is she who lays the foundation for the evolution of the species, the process of speciation.
A population involves a supraorganismal formula, while it cannot live in isolation from the outside world. In some cases, mating of animals belonging to different such biological units may occur. With absolute isolation provoked by geography, ecology, or other factors, mating animals within a population can initiate the formation of a subspecies first, and then a species of living creatures that are different from the ancestors.
Population features
There are different individuals within the population. They differ among themselves by sexual characteristics, age and a number of other features. The number of individuals with different traits is correlated with the number possessing other qualities (say, being male and female) from time to time in different percentages. Often, indicators are determined by the time of year, nature, environmental conditions.
The birth rate and mortality rate of living creatures within a population determines its number. With the continued similarity of these two parameters, the number remains constant. Environment, interaction with other species, populations often provokes internal changes, including abundance.
Population, Species, and Matrimony
In order for some species to continue to exist, as laid down in the genetic program of any living creatures, it is necessary to take measures to prolong the genus. In most cases, this implies a mating season in animals, and the goal of mating is to create offspring. However, as scientists recently found out, all this is subject not only to rigid instincts - animals are also characterized by emotions, albeit slightly different than human ones. Nevertheless, attachment forms between individuals, jealousy can manifest itself, and recently, biologists find more and more confirmations and other emotions that were previously considered unusual for the animal world. In many ways, knowledge of this became available when observing exceptions from the ethological criteria of species.
Scientists receive the greatest amount of information by observing the behavior of animals in natural conditions for them. Some traits are innate, while others appear over the years as a result of attempts to survive. Only with constant monitoring of the development of the population can we understand exactly what features appeared in what way. For example, the creation of a nest, a house, a dam, a web will be innate skills. Secondary - these are models in the implementation of which animals can reproduce in their behavior. At the same time, differences in demonstrative behavior make it possible to determine a suitable female, achieve it, and find food.
Nature: mysterious and incomprehensible
Often, upon initial observation, it seems to a person that an animal behaves completely pointless, illogical, and inconsistent. Nevertheless, further observation shows that it was precisely such behavior that helped him find the necessary object, another individual, and the final movement in the sequence of sequences becomes decisive, quick. Such a realization of desire “in one throw”, as a rule, represents the embodiment of an innate instinct.
The acquired features of the individual in the process of education by parents, the pack. Social interaction allows you to acquire an abundance of various patterns of behavior. At the same time, the mechanics by means of which, say, the ethological criterion of a protein is realized during the mating season, proteins are congenital, but not formed over time.
Ethological criteria for animal species: examples
The males, caring for the representatives of the opposite sex, conflict with each other, and the choice of the female will be a signal to one of the two to leave "from the battlefield." To attract the attention of the target individual, the strangest possible behaviors are often used. Some dance, others make specific sounds. Some animals show a bright color feathers, wool. Each step, movement, color, pen is subject to the rules formed over many years and centuries of evolution.
Marital courtship is a period when animals clearly adhere to the prohibitions established in their society, including time limits. Porcupine is a very characteristic example of this restriction. The sexual instinct in these animals causes a sharp, vivid reaction: females are naturally given a fairly short period of susceptibility to mating. Playfulness is characteristic of young animals in June-July, in August they become nervous, ease disappears completely, the nature of games changes. Males are peculiar as if crying intonations, they lift each other up, but do not touch females, and female individuals are unfavorable to attention to themselves. Nevertheless, the males do not stop pursuing the female until she makes a choice in favor of one, but without a pronounced rapprochement. Animals use distracting maneuvers, delaying the moment of communication. As soon as the female feels her readiness, she gives a signal to the partner and becomes submissive, refuses food. This lasts until November, when the female initiates the process of rapprochement. Thanks to the exact timing, pregnancy is almost always achieved by a single act. After mating, the female expels the male and gives birth to one cub, from the very beginning quite adapted to life, due to which his mother has a certain freedom. The cycle repeats.
So similar, but so different
Quite interesting observations can be made if we pay attention to the ethological criteria of the hare and the hare. They belong to the genus, uniting three dozen species, but on the territory of our country it is most often found precisely a rodent, a white hare. The name reflects the external characteristics of animals: the first can lighten up by winter if it lives in the north but does not turn white, and in the southern regions it retains the same color all year round, but the second “dresses” in white for the winter, only the tips of the ears remain black . These two species have small differences in structure: the white hare is usually lighter, it has shorter ears, but the brown can grow up to seven kilograms.
Hares reproduce up to four times a year. More often, from two to seven offspring appear in the whites, but the Rusak usually has only two hares, or even one. In just a week, young white hats begin to feed on grass. For Rusaks, this period is somewhat longer - about two weeks from the moment of birth.
Dominant and reproduction
The concept of dominance was introduced in biology at the time of the rise of science in the Soviet Union. The term was proposed by academician Ukhtomsky. By dominance, he proposed to understand such a principle that governs the functioning of the central nervous system. The external environment provokes irritation of the nervous system, due to which specific hormones are generated. This leads to nervous excitement, on the basis of which a behavior model appears and is preserved.
At the same time, other centers of the nervous system are inhibited if they are not associated with a specific behavior model. If an extraneous external stimulus appears, even insignificant, during this phase, it is addressed to the excited part of the central nervous system, strengthening it, and other elements of the nervous system are even more inhibited.
And on examples?
A characteristic manifestation of the central nervous system dominant can be observed in the behavior of frogs. After winter, the males are characterized by the so-called hugging reflex. External irritation (say, a pinch) only provokes an intensification of the reflex, although in a normal situation the animal would start to defend itself or try to leave the place where there is an irritating factor. Instead, a new stimulus provokes an increase in the dominant during inhibition of other parts of the nervous system.
The described state of Ukhtomsky was characterized as a sexual dominant. This factor later attracted the attention of Arshavsky, who was engaged in age-related physiology. He noted that reproduction is always a cyclic function, and the cycle is divided into phases, each of which has its own dominant. Sexual provokes physiological changes that change the behavior of females, then there is an increase in external stimuli. What is curious: as scientists have found out, the fact of castration can greatly affect the behavior of animals. If this happened before the moment of the first sexual contact with an individual of the opposite sex, then there are no characteristic reflexes of behavior, but during castration after the first sexual intercourse the animal will make similar attempts in the future. This is due to the peculiarity of reflexes associated with the sexual dominant, which even the absence of a hormonal component does not interfere.
What's next?
At the end of the genital comes gestational dominant. This is a relatively long-term condition, and its duration is determined by the peculiarity of a particular species: the duration lasts as much as pregnancy. For example, at the possum it is only 18 days, but the elephant is bearing the fruit for 22 months. The situation is under the control of specific hormones that change the mother’s body and create conditions for the development of the fetus. This dominant is opposite to the sexual one, and the female does not allow the representative of the opposite sex even close after pregnancy.
Pregnancy is replaced by a period of offspring production. In science, it is customary to designate a generic dominant. It is followed in a logical way by a lactational one, involving the feeding of a cub.
This is curious: how do elephants behave?
The elephant is one of the very interesting animals on our planet. It has a developed intellect and a rather complex structure of relationships within society. Often, the male and the female interact very delicately with each other. As researcher Carrington once stated, there are no other animals on our planet that are equally emotionally suited to the issue of reproduction.
The males of the elephant live separately from the females before the breeding season and join the family only at the moment when the female’s body undergoes appropriate changes, preparing it for reproduction. Courtship lasts quite a long time, after which the couple goes to a secluded place and does not part: it begins a period of flirting, courting one another. Elephants use trunks, interacting with each other, stroking each other and even bind them with knots over their heads, showing growing sensuality. They are peculiar to peculiar sounds: males - lower, females - gentle. This period lasts several weeks, is adjusted to a greater extent on the initiative of the female, whose behavior changes to draft. At the time of sexual intercourse, animals have neither violence nor rudeness. The fertilized individual returns to the herd, and the male is looking for a new pair. Elephants are not monogamous, and when caring for a newborn baby elephant, the mother does not let males close. It lasts about three years.
Monogamy in the animal kingdom
How many species of polygamous animals are known, just as many are known also where the rules of monogamy are. These are the wolves, coyotes. When the mating season is finished, the male remains next to the female, lives with her in the same den and takes care of both her spouse and children. The duties of the male representative are food production, family protection. The male helps to train and feed the cubs. Upon reaching two or three years of age, young wolves are ready to create a new family. Before the pair is formed, the courtship period lasts for a rather long time, in fact, the choice of a partner begins at the age of one year. Observations showed that wolves are characterized by jealousy, sensitivity.
I want a harem!
Indeed, this is also observed in the animal world. Typical inhabitants of water open spaces with similar tactics of social inter-gender interaction are fur seals. Of those living on land, zoologists are especially interested in antelopes and saigas. Often, a harem in antelopes has up to five female individuals, and in seals - up to eight dozen. When trying to escape, the female individual is placed in its rightful place, and the procedure is accompanied by punishment.
What about the monkeys?
Since the time of Darwin, it was the monkeys that caused particular interest in the scientific community. These animals are characterized by rather peculiar habits and ethological criteria. Mating is usually quite free, without a time frame; in most cases, the males initiate the process. According to the scientific classification, monkeys belong to polycyclic animals, and they are not characterized by fertilization in a strictly defined time period. The eggs in the organisms of such animals can mature many times a year.
Inter-sexual relations in monkey societies vary greatly among different species. Gibbons, orangutans very carefully, carefully select a pair for marriage. These animals are characterized by a long courtship period, accompanied by walks, games. For a relationship they need feelings, and tenderness is gradually increasing. The couple leaves their parents, forms a family. At the same time, animals are jealous, up to the point that adult females are expelled by their parents from the nest. A completely different society of baboons was built. Here, any female of the appropriate age can enter the game with the male, but when approaching a favorable period for conception, she attracts the attention of the leader. A pregnant individual is under its protection until childbirth. This is logical, because the leader is the strongest individual in the pack, and it is precisely with him that the offspring will be the best. Gorillas, in turn, act very differently - males, although they are leaders of the flock, do not start a harem, and other males can mate with females.