What do all members of the swine species always have in common? They always have the same number and kinds of chromosomes. They are always preyed upon by the same predators. They always occupy the same habitat at the same time. They always occupy the same position in the food web no matter where they live.

Members of the swine species always have the same number and kinds of chromosomes

Explanation:

The swine species always have their food habits in common. They are omnivorous and they also due to ancestry have the typical type of genes and chromosomes inscribed in it. Hence swine are used in research industry nowadays like dogs and monkeys.

Wild boars, hogs and pigs all have just small differences externally. Their anatomy and physiology are identical. They are all mammals. They are highly intelligent and talented ones. They have their physiology identical to ours which helps in research scientist to experiment and finds cure for human.

biological definition of species, which works for sexually reproducing organisms, is a group of actual or potential interbreeding individuals. There are exceptions to this rule. Many species are similar enough that hybrid offspring are possible and may often occur in nature, but for the majority of species this rule generally holds. The presence in nature of hybrids between similar species suggests that they may have descended from a single interbreeding species, and the speciation process may not yet be completed.

Given the extraordinary diversity of life on the planet there must be mechanisms for speciation: the formation of two species from one original species. Darwin envisioned this process as a branching event and diagrammed the process in the only illustration found in On the Origin of Species (Figure 1a). Compare this illustration to the diagram of elephant evolution (Figure 1b), which shows that as one species changes over time, it branches to form more than one new species, repeatedly, as long as the population survives or until the organism becomes extinct.

Explanation:

For speciation to occur, two new populations must be formed from one original population and they must evolve in such a way that it becomes impossible for individuals from the two new populations to interbreed. Biologists have proposed mechanisms by which this could occur that fall into two broad categories. Allopatric speciation (allo– = “other”; –patric = “homeland”) involves geographic separation of populations from a parent species and subsequent evolution. Sympatric speciation (sym– = “same”; –patric = “homeland”) involves speciation occurring within a parent species remaining in one location.

Biologists think of speciation events as the splitting of one ancestral species into two descendant species. There is no reason why more than two species might not form at one time except that it is less likely and we can conceptualize multiple events as single splits occurring close in time.

Allopatric Speciation

A geographically continuous population has a gene pool that is relatively homogeneous. Gene flow, the movement of alleles across a species’ range, is relatively free because individuals can move and then mate with individuals in their new location. Thus, an allele’s frequency at one end of a distribution will be similar to the allele’s frequency at the other end. When populations become geographically discontinuous, it prevents alleles’ free-flow. When that separation lasts for a period of time, the two populations are able to evolve along different trajectories. Thus, their allele frequencies at numerous genetic loci gradually become increasingly different as new alleles independently arise by mutation in each population. Typically, environmental conditions, such as climate, resources, predators, and competitors for the two populations will differ causing natural selection to favor divergent adaptations in each group.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.