Climate change. When this theory was first introduced to the world, it was something that many of us feared, or denied. A term that spelt catastrophic changes to our environments and as a consequence, numerous disaster movies. From rising sea levels to species extinctions, climate change encompasses a wide range of changes that could and are occurring, due to our globes warming temperatures. Now, if I were to write an article on all the current and future impacts of climate change, we’d be here a good while. It wouldn’t be an exaggeration to say that birthdays, Christmases and Easters would go by and here I’d be, still writing (probably not very well), and here you’d be, still reading (if you didn’t give up) an astronomical essay, verses one to one million. No, instead, this article is focusing on a very particular impact of climate change, a species impact. One, which is slowly becoming more common. What is it? One word: hybridisation.
Hybridisation is quite simply the breeding of two different organisms to form a new species. The liger or tion for example, hybrids of lions and tigers, exist in the world today. There aren’t many, but they exist. But the hybridisation I am talking about has been a totally natural one, occurring as a result of our changing climates. Climate change introduces to you the pizzly bear or the grolar bear. Yep, you guessed it, a species produced when a grizzly bear and a polar bear breed. So, which is which? Well, if the father of the offspring is a grizzly bear, they are referred to as a grolar bear and if the father is a polar bear, they are pizzly bears. Great names granted, but is this phenomenon great? Why are polar bears and grizzlies mating? And what does this mean for the grizzly and the polar bear?
Grizzly bears are usually found in Canada and Alaska, and polar bears of course, are found mainly in the Arctic Circle. However, as a result of climate change, temperatures are increasing and grizzly bears seem to be moving further north with the warming climates. In addition to this, as Arctic ice thins earlier in the season and disappears quicker, polar bears are spending more of their time on land. This is bringing grizzlies and polar bears into more frequent contact and causing the two species to breed. Due to the similar genetics of the two species, males of each species will mate with the females of each, causing this hybridisation. Recently, a bear shot by a hunter in northern Canada is thought to be a hybrid of the two species, with white fur like a polar bear, but the head shape, paws and claws of a grizzly. Occurrence of these hybrids have been confirmed in previous years through DNA analysis.
Although the hybrid bears are thought to be rare, sightings of them are increasing, leading scientists to believe that they are becoming more common. In the long term, it is thought that there could be an evolutionary change, as polar bears in particular struggle more and more with diminishing levels of sea ice, impacting hunting and breeding. However, although there is a change, it is likely to be hundreds of years before the world sees a population of a new bear species. So, what do they look like these hybrids? Those that have been spotted are either white, or a light brown colour, they have dark rings around their eyes, with dark paws and longer claws, more similar to a grizzlies claws than a polar bears. Because they are a new hybrid, little is known about the bears temperament. However, as both grizzlies and polar bears generally try to avoid humans, it is thought that the pizzly/grolar bear, will be much the same.
Climate change continues to change our environment in ways that many of us could not and have not foreseen. The grizzly-polar bear hybrid is just a tiny fraction of the changes that we may see as a result of climate change and it most certainly will not be the last.
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