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Several young kids' first encounters with hybrids in nature are mules. Mules, a cross between a donkey and a horse, are well-known for their power and agility but not for their procreation. According to traditional opinion, hybrid species cannot emerge without human interference. For one thing, the hybrid will be unable to have offspring, and for another, it will not fit into either parent's ecological niche.
Because of this assumption, scientists were taken aback when we first discovered hybrid bears in the wild.
When Did We First Discover The Hybridized Pizzly/Grolar Bears?
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The University of Alberta's Andrew Derocher, a professor of ecology, was out hunting with an Inuit hunter in 2006. Then, a CB radio signal announced the shooting of a peculiar bear just a few kilometers away.
At first glance, the bear recovered on Banks Island, Canada's Northwest Territories, appeared to be an odd specimen. It looked like a grimy variant of the fearsome Arctic predator, the Polar Bear, with its ratty white fur and flecks of brown fur. Its claws were abnormally long and had black rings around the corners of his eyes, like shades.
Derocher later discovered that that bear was the first ever documented grizzly-polar bear hybrid in the wild. Numerous similar hybridized bears have since been discovered, and they've been given the names "grolar bears" or "pizzly bears."
What is Hybridization?
Different species don't typically mate. But if they do, the children they produce will be what are known as hybrids.
Every animal's cells contain DNA molecules that contain instructions. These determine an animal's appearance, behavior, and vocalizations. When animals procreate, their offspring inherit a blend of DNA from both parents, which means they may inherit a combination of their parent's characteristics.
The parents' DNA is fairly similar if they come from the same species. However, DNA differences from species or species groups will be greater. Therefore, hybrid babies are more likely to carry a diversified set of genetic markers.
What then occurs when the DNA of two animal species combines to create a hybrid? There are numerous potential results. Sometimes the hybrid is incapable of surviving or is inferior to its parents. There are chances that it will be stronger. Sometimes it's superior. Sometimes, it exhibits behavior more akin to one parent species than the other. And occasionally, it exhibits behavior that is a mix of both parents.
Scientists are attempting to comprehend this phenomenon's mechanics, known as hybridization. They discovered that hybrid birds might follow unexpected migration routes. Some hybrid fish are more prone to being eaten by predators. Additionally, how rats breed may impact the diet of their hybrid progeny.
What Caused The Grizzly and The Polar Bears To Mate?
According to scientists, the Arctic warming up twice as fast as the rest of the globe, and habitat theft are the most apparent reasons for these Grolar and Pizzly Bears.
According to evolutionary research, Polar and Grizzly Bears are closely connected, distinguished primarily by coloration and habitat, but regarded as distinct species. Polar bears, alongside 34 other species, are now being impacted by shrinking arctic ice, as per Nature Journal. This new area has been dubbed the 'Arctic Melting Pot.'
As Arctic ice shrinks, polar bears are increasingly spending more time on land, which leads them to lose body mass and decrease in population because they cannot search for preferred prey like seals.
As their habitat warms up and humans take more and more of their habitat, grizzly bears in Alaska and Canada seem to be migrating north and coming into contact with polar bears along the coast.
Polar bears and grizzly bears have been spotted near whale carcasses owing to their greater probability of coming face to face, causing them to start engaging in opportunistic breeding.
It's as if two families had been living independently in nearby homes for a long time. Then humankind came on and tore down the walls separating them.
Are Pizzly And Grolar Bears Going To Be Okay?
There is a reason why scientists are concerned about these discoveries. While hybrid animals appear to be a simple solution to the issue of biodiversity loss, experts are nonetheless concerned.
To begin with, while Pizzly and Grolar Bear hybrids are reproductive, many other hybrids are often not. Infertile offspring are a huge challenge to the animal populations that devote many resources and time to nurturing their offspring.
Furthermore, hybrids are rarely found thriving in nature. For example, the shorter neck of a Pizzly and Grolar Bear renders it a poor swimmer, while its extended claws make it challenging to cross ice. However, some consider localized environmental concerns a thing of the past. Mankind has breached the rules that govern how the environment is meant to function. Wildlife must now follow suit to survive.
Some experts wonder if hybrids are the next natural step in a new world that the Pizzly and Grolar Bear's forefathers couldn't keep up with.
Will Global Warming Bring On More Animal Hybrids?
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Global warming-induced animal hybridization reaches far beyond bears. In 2010, Nature published a research study that enumerated 34 potential and existing hybridizations of the Arctic and near-Arctic sea creatures triggered by climate change.
These creatures have preserved a fairly stable number of chromosomes over time, which makes them especially promising options for hybridization. Here are some of the list's highlights and some more fresh surprises.
Harbor and Dall's porpoises have previously been spotted around each other along the British Columbia coast. The relationship is expected to continue as harbor porpoises migrate northward from the warmer waters of the North Atlantic and North Pacific towards the natural waters of the Dall's porpoises.
The National Oceanic and Atmospheric Administration's (NOAA) National Marine Mammal Laboratory discovered a bowhead-right-whale cross in the Bering Sea in 2009. Due to climate change, right whales from the Northern Pacific Ocean and North Atlantic will eventually migrate northward into the Arctic Ocean, the territory of bowheads, and co-mingle their genetics.
Beluga whales and narwhals created the very first "hints of Arctic hybrids". In the late 1980s, a whale skull presumed to be a narwhal-beluga hybrid was discovered in western Greenland Regional hunters also have recounted spotting whales that resemble a combination of narwhals and belugas.
As the southern flying squirrels penetrate northerly environments, researchers in Ontario, Canada, are looking into the propensity of hybridization. The hybrid squirrel combines the size of the southern variety with the coloration of the northern type's belly.
Spotted seals can be found in the western Beaufort, Yellow, Okhotsk, Bering, and Chukchi seas. Ribbon seals live in the same areas, except for the Yellow and western Beaufort seas.
These animals are dependent on sea ice, and the melting of ice will lead to an increase in population overlap. The University of Alaska Fairbanks Museum has a specimen on display that shows a possible hybrid origin.
Is Hybridization Bad For The Animal Kingdom?
Hybridization isn't inherently a terrible phenomenon. It has been a major source of evolutionary innovation. For instance, a distinct chub species evolved in the Colorado River prior to humanity's arrival by the hybridization of two preceding species.
However, human-induced hybridization typically occurs rapidly and reduces genetic and species biodiversity. In the 1860s, when mallard ducks were brought to New Zealand, they started breeding with the indigenous gray ducks. Few, if any, pure gray ducks are left today.
If, for example, North Pacific and North Atlantic minke whale subspecies hybridize in the Arctic with less ice, the loss of biodiversity may be minimal.
Other crossings pose a greater challenge. Suppose the North Pacific right whale, estimated to comprise barely over 200 individuals, and the bowhead whale, which has a much larger population, mate together. In that case, the former could be pushed to extinction rather quickly.
This illustrates that unless polar bears can find safe havens in distant areas, interbreeding could be the start of the end for the species.