The day that Alfred Russel Wallace took note of the astonishing variety of birds he was continuously surrounded by during his time in the Malay archipelago, marked a crucial turn in man's knowledge of the world around him. *
Of course, it was only when Charles Darwin published his new-fangled theory about evolution that it would have the world gasping out loud.
(Some would say it's a purloined theory, a notion removed from Wallace's poor, uneducated and un-connected hands by Darwin and his well-to-do society cronies. But that's a tale for another time.)
No matter who gets to take the prize for putting the two and two together, it's evolution that has decidedly and dramatically changed (and in some cases polarized) human understanding of the planet and our place on it.
This post, however, is not exactly about that.
Bear with me!
I was watching David Attenborough's "The Life of Mammals" on the Knowledge network last night (nerd alert, nerd alert!), and was struck by the super-specialization that some animals (birds and mammals alike) have developed to take advantage of their given surroundings.
Take for instance, the Koala.
It survives singularly on the leaves of the Eucalyptus tree.
True, there's more than one variety that they dine on, but generally they restrict themselves to the leaves of only 2 or 3 varieties for all of their nutritional requirements.
Now, eucalyptus leaves are not particularly nutritious, nor are they easily digestible.
The Koala actually spends the majority of its waking hours (which totals only about 5 hours on the best of days) just trying to get enough to sustain itself.
So.
Why only one type of sustenance?
Here is another example that I can't quite wrap my head around.
There's a type of bird which is so highly specialized that without the male or female in a mated pair, the other would die.
Here's why.
The male bird has such a specialized beak that it is really only capable of cracking the nuts that it finds.
Unable to pick out the pieces of nut meat, it relies on the female birds more delicate beak to pull out the nutrients and actually share the contents with him.
Without him, she is incapable of accessing the meat.
Without her, he is unable to benefit from the contents.
(I have looked high and low on the internet to find the name/bioregion of this particular bird, and even called several friends. Does anyone know which bird this is, what it's called, or where it could be found?
I don't have a reward to offer...will my eternal gratitude suffice?)
So. Anyway.
Here's my query. The true reason behind this post.
Why would any creature evolve to such a point that a single change or deviation from the norm might result in the total devastation of the entire population.
I thought that evolution was supposed to give creatures the MOST ability to cope in their environment, not restrict it.
Can it be that some creatures are 'devolving' into oblivion?
What accounts for the creatures that specialize themselves out of existence?
*If the story of the intertwined lives of Alfred Russel Wallace and Charles Darwin seems interesting, may I humbly recommend "A Delicate Arrangement: The Strange Case of Charles Darwin and Alfred Russel Wallace"?
It's a really elegant, well researched book on the life of Mr. Wallace and his major contribution to the 'theory of evolution'.
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14 comments:
Personally, I think evolution has too big of a safety net these days. Take monkey bars for example. When I was growing up you could hang upside down from about 20' and if you fell, you fell onto concrete or gravel. Today, the monkey bars are plastic and less than 10' off of the rubber padded ground.
Is anyone else concerned about the ramifications this will have on our species?
It is the mechanism of evolution that results in freaks such as the one you have described. A gene mutation initiates the process. This is not an isolated occurence - gene mutations happen all the time. It is accidental an anomaly. Some of these mutations die away - others fare better in their environment. A viable mutation is selectively chosen and begins to dominate. It becomes the evolved species. Ofcourse this takes thousands of years unless it's a virus strain!
Read about the peppered moth of England and its evolution in England. That's a classic case.
Perhaps an accidental mutation that caused this anomaly in the beaked bird you speak of, had a selective advantage over other mutations.
Snow
Nature experiments with different types of priorities through different species. Experimenting constantly as to survival techniques. The Koala is safe from intrusion when sticking to one type of food that doesn't interest others. It survived that way. On the other hand, there's a risk- one type of food can always run out. The birds that are forced to share with females are birds that mate and share, hence the survival of the species. There's no freak incidence, no anomaly- there's too much involved! There is just difference.
Mutations can be good OR bad for the species, and those that become highly-specialized (marsupials in Australia for example) are at risk for extinction should their enviornment change so evolution does not work in the favor of all species.
Interestingly, languages work the same way, those that are highly complicated and specialized tend to die out and the "simpler" tongues thrive until eventually they become more dominant.
Sincerely, Koala food and bird patterns are Not, so not, "mutations". Can we drop it? :0)
What food would you choose if you where limited to only one? Perhaps Oysters?
In response to fjl's reply....
I should think that, in the case of the birds, a mutation is involved because a physical attribute is apparent. The symbiotic behaviour between the male and the female is integral to the survival of each, because the physical differences can not allow them to survive on their own... it could be an instance of behaviour modification due to mutation. It wouldn't work, the other way around -- that is, modifying their behaviour isn't going to result in a mutation, but a mutation would certainly result in behaviour modification. N'est pas?
You certainly wouldn't want to piss off your spouse to bad if you were like those birds.
If you're talking about "mutation" as a positive evolutive facet in some rare cases, alright.
...but Koala leaves? :-)
Are humans any different? Do you think the average neurosurgeon could survive in the wilderness as well as a simple farmer? I've always thought our society was evolving to the point where generalists are being replaced with specialists limited to specific areas.
As a species we really are getting ourselves into being like ants in an efficient ant hill. We have become (as a society) utterly dependant upon one another, and utterly at the mercy of each other's services (oil refineries setting the prices for EVERYTHING being a prime example) Think of the farmer ants and the leaf cutters and the nursery ants all needing each other to function as a whole. Goods and Services are so deeply exchanged now and so specialized that it is only a very rare and "unattached" human in Canada that can live outside the network entirely. But unlike ants, we are also in fear of each other's talents, afraid of having our things stolen, our safety compromised. It is a scary thing. We have become as specialized as these birds, but instead of depending on our mate, we individuals depend on enough of everyone doing their jobs for our survival.... thank you doctors, cops, farmers, garbage collectors, phone, hydro, water and everyone else that goes to work so that I can buy anything from anywhere on this planet to eat or use while being safe in my nice home, built by several specialists, heated by whatever special means..... etc, etc, you get the picture!
Oysters.
Definately oysters.
But seriously folks.
I don't know if mutations (which are fascinating unto themselves) was were I was going with that post exactly; it was more of a query as to the SENSE of such extreme specifications.
Interesting topic, though, I'm quite enjoying everyones thoughts on the subject!
I absolutely love this story about the birds which depend totally upon one another. That is the way a relationship should be, don't you think? I don't know what kind of birds they are, but I'd be curious to know too. Thanks for posting that :-)
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