Brown Bear

Brown Bear
Ursus arctos
300,000 – 1,000? Years Before Present
Paper cut-out bears, Pleistocene bear foot and leg bones, ancient bear DNA sequenced by Dr. Ceiridwen Edwards, University of Huddersfield

Whilst memories of beloved teddy bears might bring a nostalgic glow to the thought of real bears having roamed the Clwydians, the ‘terrible teeth and claws’ aspect of Ursine identity makes their absence something of a relief. Whichever vision they conjure in your mind’s eye, here they certainly were.

Most of us warm to the idea of a bear, perhaps because (apart from being ‘cuddly’) they remind us of ourselves. This is probably why the polar bear has been adopted as flagship species for the environmental movement’s action on climate change in the Arctic. And also the reason that the media have reported with a sense of horror that rising temperatures are impacting on polar bear ranges, causing them to come into contact with grizzlies – with whom they then interbreed.

Alarming though this sounds, the sequencing of ancient bear DNA demonstrates that – as with other close species – occasional ‘dangerous liaisons’ have always occurred at the periphery. In what at first seems an extraordinary finding made by a team led by Dr Ceiridwen Edwards (now of the University of Huddersfield), it transpires that all modern polar bears are descended from (now extinct) Irish brown bears. And in similar vein, studies of contemporary grizzly bears in Alaska show that they have varying degrees of polar bear within their genetic make-up. All of which suggests a certain plasticity – which, in turn, challenges our notion of what a species actually is.

Perhaps this shouldn’t surprise us. We now know that many of us have a Neanderthal component within our DNA, evidence that human species interbred in the past. The very idea of a species as something set in stone is, it seems, somewhat flawed because everything is in constant motion, changing in response to its surroundings and the things it bumps into. But BIG problems come when change happens very quickly – as is happening now – and species can’t adapt quickly enough.

So whilst the idea of a pizzly bear (as these hybrids are called) is then less unnatural than it might at first seem, this doesn’t mean that the threat of human-caused climate change is a sham, nor does it diminish the reality that the ‘unnatural’ forces (ie. us) that are causing it are also unleashing a tsunami of toxins into the environment. This represents an equal threat to all life on earth – ourselves included. In fact the current scenario is a disaster for Homo sapiens in particular, because we have come to expect – to demand – stasis, our increasingly urban civilisation being founded on it. Consequently we’ve become deeply resistant to the idea of change because it’s become much more difficult to change. This inflexibility will not enhance our chances of survival. Maybe we need to be more plastic (rather than overwhelming Earth’s ecosystems with it).

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