Sunday, August 28, 2011

Polar Bears, God, and Evolution

can evolution save the polar bear?

There have been recent reports of polar bears hybridizing with grizzly bears: is this a good thing?  Normally the two never meet.  Though it's easy to think of places like Alaska as being just "north," in actuality the habitats are more subtle than that.  More or less everywhere in Alaska on the main "land" part of the state (forest, rivers, mountains, and open tundra), the grizzly bear survives.  Some eat a lot of salmon, some are more vegetarian, but they are found widely and the eat just about everything, from mice to garbage to human beings.

The polar bear lives in Alaska but off the coast, on the sea ice or along the beaches.

Most of us have probably just seen a polar bear stuffed, usually in a museum (though the airport in Anchorage has a dandy one, and my wife says that the White King casino in Elko, Nevada, purports to have the largest record in the world on display).  Here is one from the San Diego Museum of Natural History.

The Los Angeles Zoo always had polar bears on display when I was growing up, though I learned later that they had to use bleach to keep the fur from going green with mold.  Here is a recent shot from the San Diego Zoo, with a bear chomping on his morning "enrichment": a treat of carrots, which I assume have the snap, crackle, pop of seal bones.

Their usual diet though is meat, and lots of it, sometimes in the form of a dead whale but usually from seals.  Part of a polar bear's daily intake is indicated by this fridge full of fiberglass meat, also at the San Diego Zoo.

As the reality of global warming begins to show its effect (and please note, I am not saying anything controversial, such as the fact that I drove to work today caused global warming; I merely saying that in the Arctic, ice sheets and glaciers are melting: I have seen it first hand), polar bears won't be able to hunt seals. 

What next?  Can they learn from grizzly bears, switch over to tundra food like mushrooms or voles or dead caribou?  One one hand, it seems plausible.  If we look at the skulls, we can see how close these two species are.

(This display also is in the San Diego Natural History Museum.  AVC biologist Cal Yorke joins Hood in praising the quality of their exhibits, even as we note that some of the best best exhibits of all are in Chicago, at the Field Museum, in New York City, and in London, at their Natural History Museum in Kensington, across from the Victoria & Albert Museum.)

That explains how the two species have come to hybridize recently.  One estimate that I have heard is that they diverged as species in just the past 500,000 years or so.

Several related questions tie in with this.  Is their extinction inevitable, and if so, would cross-breeding with grizzly bears help prevent that, where does God fit in with extinction, and, last, if humans are directly or indirectly responsible for extinction, should we feel badly about that fact?

To start with these in reverse order, I do want to debunk one myth.  That is the notion that indigenous North American people (the Inuit, for example, in the far north, and other First Nation inhabitants continent-wide) are somehow more spiritually attuned to the natural world.  Certainly, they CAN be: I would like to think that anybody can become attuned to anything, from an exquisitely rendered violin concerto to the song of the Western Meadowlark to the sound of a car engine that needs a tune-up.  But in terms of the relationship to nature, humans today have a variety of complex contact points, ranging from those who think it all should be bulldozed in order to make way for more Wal-Mart parking, on over to the tree-huggers who wear hemp and don't think introduced goats should be removed from offshore islands where they are decimating native plants. 

If people rely on nature directly, they are obligated to be aware of it.  Broadly speaking, the Eskimos do have 100 words for snow.  (Well, for snow and ice and related weather.)  Yet as anybody's direct dependence changes, so to does their culture and their awareness.  My grandmother was born in Sweden, but that does not mean I know how to speak Swedish.  So too, a current-day Inuit may have identical skills and values to their sealskin-kayak-building ancestors from a hundred years ago, but then again, they may not.  It is not inevitable.  When I did stay with an Eskimo family a few years ago on an island in between Nome and Siberia, here is what was in their entry space by the front door.

This is hard to see (my photographic skills have gotten better recently) but is a broken outboard motor and an uncured polar bear hide, stiff and useless, both tossed aside in their front porch area.  They had shot a polar bear earlier in the season but had not salvaged the skin properly, and now it was beyond salvaging.  This is neither good nor bad, it is just a fact.  A polar bear was shot, and they opted not to do anything more, after skinning it.  (Any animal skin needs to be cured or prepared, if it's not to rot or become too stiff to work.)  Being of a particular race or culture does not inherently make one at tuned with nature.

The same people in this village used to hunt whales from kayaks.  Here is a picture I did not take.

I bought this in Anchorage and it's undated; from context, I would guess c 1960.  (This is from Stewart Photo, in Anchorage, who retain copyright.)  Killing an animal for food or clothing or even as an initiation rite seems to me a different interaction with nature than killing things because (armed with a rifle and a snowmobile) you just can.  The Inuit may be able to help us understand how to manage our resources in Alaska and elsewhere, but they, too, may have moved past direct reverence.  Maybe we are all "post-natural" now.

To explore this issue, this past summer I went to the Norwegian Arctic to see polar bears for myself.  My wife and I joined 18 others and 5 crew on this historic ship, the Noorderlicht ("Northern Lights").

It has an iron hull and a shallow draft, and we could explore islands and fjords inaccessible to other expedition ships, including ones being run this summer by National Geographic.  We saw 14 bears alive, and one dead one, about which more later.  Some of the yearling cubs had no idea what we were, and would come over and try to puzzle us out, like this fellow, below.

What is happening is that as the temperature of the planet changes, the thickness and the location of pack ice changes, and in turn (to oversimplify) the polar bears swim around for hundreds of miles, unable to find thick enough ice to support them and the seals they eat.  Bottom line?  They starve.  This is happening now.  I saw polar bears eating grass, I saw polar bears eating seaweed, I saw polar bears swimming in futile circles after eider ducks, trying to catch the chicks.  They were desperately hungry.

Here is what a dead polar bear looks like.  This is not a zoo, this is not Photoshop, this is just direct reality.

So what can the bears do?  If they co-mingle with grizzly bears, will that solve everything?

I wish it would, but what they need can't be replaced so easily.  You need to have paws a certain size in order to walk on snow.  You need to have a body a certain minimum size in order to have a surface-to-bulk ratio that is efficient in cold weather.  These things can't be slimmed down.  Polar bears are larger, on average, than grizzly bears, and those in turn are larger than the more southerly bears, the ones we have in Angeles Crest, the black bears.  A gazelle is slim and fast and can live on relatively small plants, but it can't survive a prolonged blizzard.  Polar bears are the size they are and the color they are for incontrovertible  ecological reasons.

I am not suggesting that we know all the facts about how weather works or what drives climate.  Nor am I suggesting that the most recent episode couldn't be a normal swing (though evidence implicates modern man fairly damningly).  But the fact is, animal distribution and the mix of what lives, what does not come back next season will change, whether we want it to or not.

Some think this may be God's will in action.  I want to know how that can fit in, then, with the concept of stewardship that so many Christian leaders and thinkers find as part of our moral obligations.  Others think that there is no such thing as evolution, because it's not directly explained by the narratives of the Bible.  One of the AVC biologists, Dr. Matt Rainbow, has thought very profoundly about this, and certainly, he is just this side of being a full theological scholar.  He knows his Bible (and his Bible scholarship) very very well.  He has a way of helping us (on the one hand) understand evolution in all its molecular complexity, while (on the other hand) still retaining room in a rigorous scientific model for a God who initiated it all.  I will not summarize all of his work here, and especially not so briefly, other than to encourage you, if this fascinates you, to talk to him during his office hours.

We have a grizzly bear on the California state flag, but now they are extirpated, which is to say, extinct here (though surviving elsewhere, such as Yellowstone National Park).  If we were to go back in time a few hundred years, the Antelope Valley would have had, yes, antelope (the species called pronghorn), and also complex grass communities that no longer exist, surface pools of water, condors, and, yes, grizzly bears.  Is it better to have Claim Jumper and dollar stores?  Maybe not better or worse, just different, but that too has implications for the future.

On the long-term scale, polar bears can evolve into something different--perhaps a kind of whale bear, able to breath through the top of its head, competing with the orca for seals and salmon schools.  But on the short term scale, their genetic dispersal through the half-grizzly hybrid scheme is bound to fail.

We will have icebergs and the northern lights, either way.  What kinds of things we want to be stewards of, from polar bears to gazelles to whales to fields of poppies, depends on the decisions we make today, on the futures we imagine, on the possibilities we inhabit.  The choice is ours.

1 comment:

  1. I sure hope so. I would hate to see the Polar Bears go extinct, because right now they are headed that way unless we save them. Every year, their population goes down by a big margin, and I know a lot of organizations are trying to do their best to save them but it's not enough at the moment. We need to all unite and do what we can even in our little ways to preserve these species.

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