Speciation in nature is combined with the laws of natural selection explored and developed by Charles Robert Darwin.
Speciation is the process of the emergence of newer biological species and their change over time according to the theory of natural selection.
At the same time, if there is genetic incompatibility, that is, the inability to produce offspring when crossing, this is called an interspecies barrier. The basis of speciation, according to the synthetic theory of evolution (STE), is hereditary variability, where the leading factor is natural selection.
There are two options for speciation:
• geographic (alopatric);
• ecological (sympatric).
Examples of ecological speciation are widespread in nature. Let's take a look at some of them.
Situation in nature
Practicing biologists note that examples of ecological speciation do notalways show up brightly. There are groups of individuals that do not interbreed or interbreed little, regardless of the background conditions. For example, black grouse or capercaillie are completely different species, but they can genetically interbreed. The following examples are: dog, wolf and jackal; most of the deer species. In speciation (geographical, ecological), the main event is the appearance of natural actual isolation of biomorphs, even if they live in the same area.
This concept refers to the process of formation of new species in coinciding territories. It is the ecological features of development that do not allow them to interbreed, because the populations occupy different ecological niches. How should this be understood? In nature, in different variants, examples of ecological speciation appear in the comparison of urban and rural swifts. If they are in the same cell, then they will not have offspring. They have different morphological and physiological characteristics.
Development of traits
The most obvious example of ecological speciation is the formation of additional characters of the same species, but in different territories.
For example, there are species of buttercups and tradescantia that have adapted to grow in different conditions - fields, meadows and along river banks, in different natural habitats. Polyploids are also observed, in which the number of chromosomes is different. In animals, convergence occurs - the convergence of signs, and similar structural features of the body.
Such examples of ecological speciation are observed in nature also in the structure of body shapes in fish: cartilaginous sharks, ichthyosaurs (extinct) and dolphins. This is the result of convergence in animals belonging to different classes.
In nature, the end of speciation is reproductive isolation when existing obstacles are eliminated, regardless of geographic or environmental factors. Whether the newly emerged generation will exist, disappear, or split into small biological groups depends on the emerging interspecies relationships. Examples of ecological speciation show that biodiversity in nature is necessary for evolutionary development.