Survival of the Weak and Scrawny

Mike Clawson here…

newsweek_reverse_evolution1

Newsweek had a really fascinating article this week about how hunting practices are leading to a kind of “evolution in reverse” as hunters kill off the “best” animals (whether elk, or elephants, or mountain goats, or whatever) and leave the weak and scrawny ones to propagate themselves. Of course, the article acknowledges that it’s not really “reverse” evolution, it’s just a shifting definition of “fittest”. When you add humans into the mix as a predator, suddenly large tusks or a big rack of antlers is no longer a survival trait, but becomes a detriment. Thus, the article reports, most elephants in Asia and Africa no longer have tusks, and mountain goat’s horns are getting smaller and smaller.

However, the article also cautions that this sort of “selective breeding” by humans may actually threaten the viability a species if hunting ultimately leads to a narrower and weaker gene pool. If you take out the most adaptive and best breeders of a species, the animals that are left might not have the genetic resources necessary to adapt to changes and challenges in its ecosystem. This could ultimately lead to extinctions, or at the very least, and somewhat ironically, the disappearance of exactly the kind of animals hunters most desire.

Anyhow, if I wanted to tie this into religion, and be a little snarky towards my Creationist friends and family, I could point out that here we have an obvious example of evolution at work. Right before our very eyes we can see Darwin’s principles being played out. However, I’m not really interested in picking a fight. Besides, most Creationists I know like to make a distinction between what they call “micro-evolution” (change within species), and “macro-evolution” (change from one species into another), and admit that the former happens while denying the latter. Thus they would simply say that this article describes microevolution, but doesn’t say anything about whether humans could have evolved from primates, or the like. So yeah, regardless of whether that’s actually a valid distinction or not, I don’t think you’d get very far using this article in a debate with them.

Besides, since I personally see no contradiction between evolutionary theory and belief in a Creator, stories like this don’t bother my faith in the slightest, and thus I really don’t have any agenda with this post other than to say “Hey, check this out! Isn’t this neat?!”

Peace 🙂

Kate

Besides, most Creationists I know like to make a distinction between what they call “micro-evolution” (change within species), and “macro-evolution” (change from one species into another), and admit that the former happens while denying the latter.

Hearing people use this “distinction” makes me want to smash a brick into my face. It’s like they started noticing that evolution DOES happen and thought oh shit…quick, let’s invent a term for anything we can see (ie, “micro-evolution”) and say it doesn’t count!! We’ll expand that to include any evidence that scientists are able to provide. muahahah!

IDIOTS. Mike, I wish all Christians (or at least more) were like you. 🙁
weaves

That is fascinating! I can’t wait to discuss this with my lecturer!

-ecology and evolution major-
MH

FYI the standard rebuttal to “micro-evolution” versus “macro-evolution” is that such a distinction would require two kinds of DNA. One to code the species and one the variations within a species. Since there is only one kind of DNA that distinction is not valid.
Mike Clawson

Hearing people use this “distinction” makes me want to smash a brick into my face. It’s like they started noticing that evolution DOES happen and thought oh shit…quick, let’s invent a term for anything we can see (ie, “micro-evolution”) and say it doesn’t count!! We’ll expand that to include any evidence that scientists are able to provide. muahahah!

I agree, on the surface, it does appear to be rather ad hoc; and that might be part of it. However, their distinction between macro- and micro-evolution is more fundamentally based on their literal reading of the Bible, specifically Genesis 1 which states that God created plants and animals to reproduce “each according to its kind”. Thus, while they have no problem with the idea of evolutionary adaptation in general, it’s the idea of one species turning into a different species that they think contradicts scripture. And of course for them that’s what it’s ultimately all about. They don’t care what science can or cannot prove, that’s besides the point for them. They only care about what they think the Bible says. So if they think micro-evolution is biblically allowable, but macro-evolution is not, that’s what they’ll believe.
Kayaker

most Creationists I know like to make a distinction between what they call “micro-evolution” (change within species), and “macro-evolution” (change from one species into another), and admit that the former happens while denying the latter.

My thumper friend believes that “border collies” are a species.

In South Carolina, our education system teaches nonsense, ala the mythological scripture.
Ann

This (hunting as a “negative” influence on fitness) isn’t a new concept. Growing up in the Midwest, I often pointed this out to my friends and family who hunt. They usually defended the practice by arguing that thinning the local “X” population (deer, e.g.) through hunting is a good substitute for the missing predator species, but of course predators such as cougars go for the weak and slow, not the robust. Nobody wants to have his picture taken next to the sickly, emaciated deer he just put out of its misery!
Richard Wade

Great article, Mike. When I was 9 or so, I first read about natural selection. Shortly after that I watched fishermen releasing any fish that were under a certain length permitted by law. They were assuming that the shorter fish were juveniles, which they might have been, but I thought that given enough time under this consistent selecting, the shorter adult fish would be common, and very few large fish would be found. I don’t know if that has happened, but it’s the same principle.

I used to weed my back yard and by pulling the weeds up by hand. Being lazy I’d not bother digging up the root. If the plant snapped off I’d leave the root, the weed would grow back and sometimes managed to flower before I got to it again. After a few years my back yard was filled with nothing but weeds that snapped off their roots easily. Evolution is happening constantly in its tiny but inexorable steps.
Miko

You also see this happening naturally through intra-species competition. For example, there are two chemicals in the human brain which control memory, one of which works better than the other. As you age, you get more of the second one and less of the first one. The leading evolutionary explanation for this fact is that this led to an earlier death for older, post-breeding humans thus freeing up resources to ensure the survival of younger humans.

Throwing humans back into the mix, you also see the same effect in husbandry and other forms of selective breeding, giving us dogs with legs of ridiculous lengths and mind-numbingly stupid sheep.

Examples like these provide an important reminder that evolution is great for adaptation to changing conditions but that it’s really not “progressing” towards any particular goal, as is often falsely assumed.
Miko

Thus, while they have no problem with the idea of evolutionary adaptation in general, it’s the idea of one species turning into a different species that they think contradicts scripture.

The flaw here, of course, is thinking of the label “species” as something set it stone. Rather, species are things we identify after the fact to describe what things look like at a particular snapshot in time. While there are some criteria in the definition to be a species at that particular instant, once time is factored in it’s an arbitrary definition based on convenience rather than on some innate property of the lifeforms themselves.
hoverFrog

It’s not really survival of the fittest but survival of the fit enough. Elephants with big tusks were not fit enough to survive and pass on these “big tusk” genes in the face of a predator that targeted them.

Speciation occurs when one group can no longer reproduce with members of the parent group. A horse and a donkey can produce offspring but these mules are infertile and so cannot continue the genetic line. There is a clear distinction between one species and another. In London the London Underground system became an attractive environment for mosquitoes. After about a hundred years of separation the surface mosquitoes and underground mosquitoes can no longer breed. They are now separate species. ==> http://www.gene.ch/gentech/1998/Jul-Sep/msg00188.html

This is evolution at work and is supported by good empirical evidence. A creationist might say that the two species of mosquito are still mosquitoes but the difference is only a matter of degree. When does a mosquito cease to become a mosquito and becomes a different form of insect? At what point is a donkey considered a different kind of animal to a horse from a creationist view?
Alex Fear

I didn’t know this was a science blog too! Awesome!
@Miko,

Good comment, I’m beginning to think along those lines myself, nature doesn’t produce species, it just produces…

With regards to hunting the strongest, how do we know for sure that the wolf would eat the strongest rabbit if it was given a choice – eg. weak small rabbit and big strong rabbit both get stuck in a trap. Along comes a wolf, does he look and consider, hmm I’ll go for the weak one and do my part to keep the rabbit populations going at an acceptable level, or does he simply eat the one which smells best/is nearest or whatever.. perhaps he eats both anyway. Interesting, is there any studies in this that predators will consciously/instinctively choose the weakest?

My guess is that a wolf would also go for the most tasty succulent rabbit (the biggest will keep him going for longer than the smaller and also less chance of getting food poisoning).
Curtis

The problem with limited “micro”evolution is time. If we can see changes in decades, imagine what billions of years can do. Oh, that’s right, the earth is only 8000 years old.
Ann

Alex, why are you imagining that wolves rely on traps for their meals? Predators don’t choose the weakest, but the weakest, slowest, etc. are the ones least likely to get away.
Or maybe I’m not understanding the point of your post…
Alex Fear

Ann,

Operative word: imagining

Perhaps I should have used it.. imagine if a wolf was given a choice between a weak and strong rabbit both of whom have been prevented from running away for some external reason (let’s say a tree branch fell on them if that helps).

Obviously in a straight race, the weakest is going to get caught first, but if there is no race.. wouldn’t the wolf go for the stronger (better meal) than the weaker?

Eg. This would mean human hunters just have better odds than the wolf but the instinct to go after the best choice meat is still the same.