Divergence is in biology what is it? Examples of divergence

Divergence in biology - what is it? In some cases, populations living in ecologically diverse peripheral environments may exhibit genetic differences from the remainder of the population, especially where there is a wide variety of species. Genetic divergence is in biology a process in which two or more populations of the ancestral species independently accumulate genetic changes (mutations) to produce a survival-capable offspring. Genetic differences among divergent populations can include mutations that do not affect the phenotype, and also lead to significant morphological and physiological changes.

Genetic divergence

At the level of molecular genetics, divergence in biology is a genetic change that occurs as a result of speciation. Nevertheless, researchers argue that it is unlikely that such a phenomenon was the result of a one-time and a significant dominant mutation in the genetic locus. If this were possible, then these mutations could not be passed on to the next generation. Consequently, the variant of successive reproductive isolation, which is the result of multiple small mutations in the process of evolution, is more likely.

Divergent evolution

According to the theory of evolution, divergence in biology is a relative phenomenon in which initially such populations accumulate differences in the process of evolutionary development and gradually become more distinct. This process is also known as the "discrepancy" and was described in "The Origin of Species" (1859). Even before Darwin, many lines of deviation from the central species type were described by Alfred Russel Wallace in 1858. According to the traditional theory of evolution, the divergence serves two main purposes:

• It allows this type of organism to survive in a modified form due to the use of new biological niches.
• This increase in diversity increases the adaptability of the younger generation to a variety of habitats.

These assumptions are purely hypothetical, since it is very difficult and practically impossible to prove them experimentally.

Molecular Divergence

What is this in terms of molecular biology? This is the fraction of nucleotides that differ from each other by two segments of DNA. The percentage of amino acids between the two polypeptides may also vary. The term "divergence" is used in this context, since there is an assumption that two molecules are descendants of one parent molecule. In the process of evolution, not only the discrepancy is observed, but also the fusion of events, such as hybridization and horizontal transfer. And such events occur much more often. Molecular mechanisms of the evolutionary divergence of the genetic material include nucleotide substitutions, deletions, insertions, chromosomal recombinations, transpositions and inversions, duplications, transformations, and horizontal gene transfer. The number of nucleotide substitutions is a simple and useful measure of the degree of divergence between the two sequences. In fact, there are several methods available for estimating the number of nucleotide substitutions and constructing a phylogenetic tree that reflects the path of divergence in the evolution process.

Convergence analogue

Divergence in biology is an analogue of evolutionary convergence, during which organisms with dissimilar ancestors became similar due to natural selection. For example, flies and birds evolved to look like, in the sense that they have wings and can fly, although their flying ancestors were completely different. In fact, these two belong to different biological types. Divergence in biology is an evolutionary event in which two morphological or molecular features have emerged from a common ancestor. These characteristics were originally the same, but became heterogeneous in the process of evolution. In the event of a divergence, there must be a certain degree of similarity between the two features in order to suggest that there was a common ancestor. For rapprochement, on the contrary, there must be a certain disparity, since certain features were borrowed from completely independent ancestors. Thus, the differences between divergence and convergence are difficult to establish.

Divergence in biology: pictures

Divergent evolution (from Latin divergentia - discrepancy), as a rule, is a consequence of diffusion of the same species in different and isolated environments. We can give the following examples: most creatures on the planet have upper limbs, in humans and primates - it's hands, vertebrates have paws, birds have wings, fish have fins and so on. All these organs are used by living organisms in different ways, however their origin is identical. Divergence can occur in any group of related organisms. The greater the number of differences available, the greater the discrepancy. And there are a lot of such examples in nature, for example, a fox. If its habitat is a desert, then the animal's coat of a certain color helps to disguise itself from predators. The red fox lives in the woods, where the "red coat" is combined with the local landscapes. In the desert, heat makes heat exchange difficult, so the ears of the fox evolved to large sizes, so the body gets rid of excess heat. First of all, the decisive role is played by different environmental conditions and requirements for adaptation, rather than genetic differences. If they lived in the same environment, it is likely that they would have developed in a similar way. Divergent evolution is an affirmation of genetic intimacy.

Divergence in nature: examples

Evolution is a process in which organisms change over time. The main feature is that all this is very slow and takes thousands or even millions of years. Divergence in biology - what is it? Consider, for example, a change in the body of a person: someone high, some low, some have red hair, others - black, there are light-skinned, there are black skin. Like humans, other living organisms also have many variations within a single population.

Divergence is in biology (examples illustrate this clearly) the process of accumulation of gene transformations necessary for survival. You can give an example from real life. In the Galapagos Islands there are many kinds of finches. When Charles Darwin visited these places, he noted that these animals are indeed similar, but they still have some key differences. This is the size and shape of their beaks. Their common ancestor underwent adaptive radiation, thus contributing to the development of new species. For example, on one island, where the seeds were abundant, the birds' beaks could not be better suited to eating this type of food. On another island, the structure of the beak helped the animal to eat insects. In the end, there were many new species, and each had its own unique characteristics.

Divergent evolution occurs when it comes to the appearance of a new species. As a rule, this is necessary in order to adapt to various environmental conditions. A good example is the foot of a man, which is very different from the monkey's leg, despite their common ancestor - the primate. A new species (in this case people) developed because there was no longer any need to climb trees. Rowing has made the necessary changes in the foot to improve speed, balance and confident movement on the earth's surface. Although humans and monkeys are genetically similar, they developed different physical traits needed for survival.