Wednesday, April 22, 2009

Die Blumen aus dem Balboa Park: Musing On Observed Evolution

Hmmm... I see the bees had already been through here.

This little Costa's humming bird was a busy glutton when I found him. He was so bent on sucking all the nectar out of the entire bush that he couldn’t care less about intrusive me and my prying camera.

Watching the feeding frenzy, I found myself wondering about how some grade school biology teachers would tell their student about the adaptation of the bird’s beak and the shape of the flower petals. How they fit so well - in some cases - that a certain type of flowers can only be pollinated by a certain type of insects or birds. Biology teachers have to be so careful with how they phrase their explanation or they’ll end up implying purpose where none is really warranted.
Adaptation by natural selection is not a purposeful nor is it a directional event. You don’t have the ‘which comes first; the flower or its pollinator?’ deal here. Both species had to have evolved together since one can’t survive without the other. The flower of a certain shape can only survive to reproduce if there also happens to also exist a pollinator that can physically enable the spores and eggs to meet... and one that is particularly attracted to the flower's particular feature. If such a pollinator didn’t already exist when the first flower with this structure appeared, then the flower would have simply died out... as many flowers and trees and animals obviously had done (and that's why 'purpose' is not inferred. If the process is directional or guided for a purpose, then there wouldn't be 'extinct losers' littering the history of this planet. Life didn't evolved on a one-on-one progressive basis. Many different varieties evolved (and are still evolving), and only those that hadn't gone extinct remain).

The pollinators also benefit from the 'fit', of course, especially when the specific hummingbird's beak type enables it to get to a food source that the other sorts of hummingbirds that have different beak-shape can't physically utilize. Then he can monopolize the food source without having to engage in more competition from other hummingbird varieties. Now... the pollinators come with varieties of their own, of course, and there is competition inside the same species (refining the 'fit') that, over time leads to greater diversity with more variations of petal shape and beak shape being accommodated by each other.

That is, until some abrupt changes in environment come about and cause a drastic drop in the population of one or more of these organisms thriving in a symbiotic arrangement. This 'bottleneck effect' is a big cause of extinction. Some organisms may survive the change, but if there isn't enough survivors to keep producing offspring that can also survive the new environment, then... Adieu, mes amis.
Il faisait bien de vous connaître ...

And here I should probably give a shout out to those who love to dismiss the phenomenon of climate change/global warming as 'unimportant' or 'not worth worrying about since the earth won't get destroyed by it'. The really intelligent folks are worrying about it not because they think that the earth won't survive but because they realize that the sort of environment this climate change/global warming is leading to may not be one that OUR SPECIES can survive very well in. See the difference? And it doesn't comfort us any if we will be able to survive but the species that we eat for food will not - which also means that the survival of the species that our food source depend on for food is also of tremendous importance to us! Among other things....
Extinction... is a cold hard fact of life. That extinction occurs over and over again to reflect the change in environment and other 'stress factors' reinforces Darwin's theory. 'Survival of the fittest', be it a bit of a misnomer since a trait doesn't have to be the fittest to survive, it just has to be relatively harmless to the organisms' survival, is NOT a theory. It is an observed phenomenon of nature. A fact of life. The theory that Darwin came up with in order to explain that phenomenon is called 'Evolution by Natural Selection'. And what it says is simple - the diversity of life on earth came about because only the organisms that have the traits that enable (or at least fail to hinder) them to survive and reproduce (passing along those traits to the next generations) in the prevailing environment are spared from extinction. 'Swim or sink, you lot' is what nature says.

The theory hinges on there already being life (it does NOT say anything about how the first life came to be in the first place), a variety of it, for that matter. And it also depends on the traits being
capable of modifications (mutations), and that the modified traits can be transmitted from one generation to the next. If possessors of a certain trait aren’t competitive enough and lucky enough to keep surviving to reproduce (not to mention finding a niche like the hummingbirds and the flowers with long and narrow tube-like petals enjoy), they just go extinct. The process is non-directional, but it is by no mean random. It is regulated by the prevailing environment (so if someone tries to tell you that ‘evolution says that things happen at random’, you should immediately look out for flying bullshit and other superfluously inane stuff that surely are about to start splattering around you).
Had life on earth been 'intelligently designed', then there shouldn't be naturally occurred extinction now, should there be? Else, the term should have been modified into 'unintelligently designed'.... in order to fit in with what the evidence says.

1 comment:

Georg said...

Balboa Parc addict Smorgy,

One of my pleasures is to fly a plane with Microsoft Flight Simulator 2004.
Now that I happen to know two persons living in Didacus Santus I had a flight there, starting in S.D. Int. Lindberg for a round trip.

On my landing approach I passed over a very big square green stretch - quite near the airport - kind of forest in the city: is this Balboa Park??