A hybrid animal It is an organism born fromcross between two different species. When two species are evolutionary close and have not yet developed reproductive barriers (as differences in the sexual organs, genetic incompatibility or diversified coupling rituals), the intersection is still possible and can give rise to one hybrid offspring, that combines physical and behavioral traits of the two parental species. This is the case of ligre (born from a lion and a tiger), del mule (born from a donkey and a mare) or of theGlular Bear (born from a polar bear and a grizzly).
Many hybrid animals arise from the intersection of species which, in nature, live very distant geographical areas among them. For this reason, their appearance is almost always linked tohuman intervention and it takes place above all in captivity. In other cases, however, the main cause lies in the climate change and in progressive Destruction of habitats due to human activitieswhich force species evolutionary to migrate until you find yourself with the distant cousins after a long journey millions of years. Being deep genetic differences Among the parental species, very often these hybrid animals are sterile.
Because there are hybrid animals and how a new species forms is formed
The birth of a new species is a process that requires millions of years and that, in most cases, begins with the separation between two groups of animals belonging to the same original species.
Let’s take a concrete example. The lions and tigers are “Sister species”that is, derive from one same common ancestorprobably lived in Asia in a geological era called Miocene. Over the millions of years, thanks to some Climate and environmental changessome groups separated and migrated to very different places. A group settled in Africawhere the wide savannah And meadow predicted predators specialized in group hunting and in Running resistance. From here the lions. Another group stopped in Asiawhere the forests and the jungle selected individuals with mighty body And striped cloakideal for camouflaging the vegetation. From here the tiger.
During the geological eras, the formation of geographical barriers (mountain ranges, raising the level of the seas, deserts) and the adaptation to specific environmental pressures made impossible for the two groups to meet again. Thus, each group undertaken one Independent evolutionary historyuntil it becomes two genetically distinct lines, each of which, taken individually, was made up of a set of similar individuals, capable of cross freely within your group and generate fertile offspring. This process, called SPECIAL, This is what gives rise to what we call today species.
What happens when two different species meet?
The answer is: Depends. When two species have been separated for a long time, such as dogs and foxes, they can accumulate genetic differences such as to develop real reproductive barriers (Differences in the sexual organs, in the times and mating rituals) that make reproduction impossible.
However, if the specification took place in more recent periods, as in the case of the tiger and the lion, the two species are still quite similar to be able to reproduce and generate a offspring. In this case, the descent shares intermediate characteristics between the two species and, therefore, takes the name of hybrid.
These hybrid animals are often sterileas the genetic differences among the parental species, first of all the different number of chromosomesdo not allow the formation of spermatozoa And egg cells Vitali.
But how does the intersection happen? Almost always, behind the birth of animal hybrids there is it Zampino of man. Sometimes to get animals with Useful features for work or of the attractions tourist to exhibit in the zoo. In other cases, however, human intervention can be indirect. The climate changethe deforestation and the urbanizations they can in fact profoundly change the habitatforcing some species to migrate from theirs territory of originuntil they rejoin with your own “cousins” After a long journey millions of years.
The case of the ligre and the tigone
In nature, tigers and lions cannot meet, living in completely different habitatsseparated by hundreds of kilometers, an ocean and vast mountain ranges. However, they can cross in captivitywhere sometimes they are coupled for advertising or exhibition purposes.
When a male lion mates with one female tiger the ligre: a feline with a golden cloak similar to that of the lion, crossed by streaks reminiscent of a tiger. These specimens can reach colossal dimensions. In the lionesses, in fact, some genes limit the puppies growthbut this regulation fails in the intersection with a tiger, allowing ligri to reach lengths above 3.3 meters and an average weight of beyond 400 kg.
On the contrary, when the father is one tiger and the mother one lioness the tigonea hybrid with more small dimensions.
These hybrid animals show behavioral traits mixedwhich complicate its interaction with parental species. To this are added frequent health problems related to their exceptional dimensions. For these reasons, the breeding and reproduction of Ligri and Tigoni are now the subject of strong dispute by the Organizations for animal protection.
Crossings between equids: from mule to zebrallo
If there is a somoma animal par excellence, this is certainly the mule, hybrid that derives from the intersection between a male donkey and a mare. A mule combines the robust build of a horse with resistance and the Trenacia of the donkeyquality that make it capable of facing prohibitive conditions for many other shooting animals. For this reason, it has been used as a work animal for at least 3000 years, often being employed for transport heavy loadssuperior to those that an equal horse could support.
When the father is a horse and the mother an ‘donkey the bardottoa generally smaller hybrid of the mule, but with similar characteristics in terms of resistance and temperament.
The equids, thanks to theirs close evolutionary kinshipcan also give rise to other curious hybrids, such as zebralloresulting fromcross between zebra and horseor it Zebrasinoborn from the union between a zebra male and adonkey.
Hybrids born from the destruction of the habitats: the grubble bear
In 2006, in Canada, a sports hunter killed an unusual appearance bear. Genetic analyzes revealed that it was a Glular Beara hybrid born from the intersection between a grizzly bear and a polar bear. Subsequently, it was discovered that it was not an isolated case.
Although, in fact, the two species live in different habitats, it dissolution of Arctic ice is pushing polar bears increasingly southwhere they come into contact with the grizzly. From these meetings these particular individuals can arise, the gross bears, with brown legs And white cloak.
Sources:
