More evolution in our lifetime.

[this charming man]

http://www.enn.com/wildlife/article/29620

A species’ evolution has long been thought to take thousands of years to produce seemingly minor changes.

It appears that in at least one case, however, evolution is occurring at what seems like jet speed. In the last 150 years, the world’s elephant population has evolved much smaller tusks....

Experts believe the rapid evolution of the massive land mammals is due to poaching.

 

[CapelDodger]

"
The largest male African elephants have the largest tusks. These tusks are extremely important in elephant behavior, with the largest tusks usually resulting in more successful intimidation of smaller males or winning fights for female elephants. But when the largest animals are killed, it changes the breeding patterns of the animals. In short, without the largest males for competition, the smaller males with their smaller tusks will breed more successfully, and their offspring will have smaller tusks."

I see a problem with this thesis. Shouldn't it be the relative size of tusk to bull that makes the difference? As in, large bull with wimpy tusk barges small male with averagely porportioned tusk aside and jumps the female anyway? Has this study been adjusted for the availability of fodder?

 

[steenkh]

Is there anything new here? It is also well known that if humans fish for larger fish, the population tends to develop into smaller-sized fish.

When we talk about evolution in our lifetime, we think of new species appearing. This is just selective breeding, and there are no new species involved.

 

[Cuddles]

When we talk about evolution in our lifetime, we think of new species appearing. This is just selective breeding, and there are no new species involved.

You don't need new species to have evolution. When it comes down to it, selective breeding is the driving force behind evolution, so saying that this is "just" selective breeding doesn't make sense. Humans killing elephants is no different from any other predator killing elephants, and the changes that occur as a result are no less evolution.

 

[steenkh]

OK. But then there is not much point in declaring "more evolution in our lifetime", because this is really mundane. We select animals for certain characteristics all the time. Elephants just join the rest of the animals who are subjected to selection through humans.

 

[Cuddles]

OK. But then there is not much point in declaring "more evolution in our lifetime", because this is really mundane. We select animals for certain characteristics all the time. Elephants just join the rest of the animals who are subjected to selection through humans.

Exactly.

Sadly, this is a point that creationists never seem to understand.

 

[aggle-rithm]

I see a problem with this thesis. Shouldn't it be the relative size of tusk to bull that makes the difference? As in, large bull with wimpy tusk barges small male with averagely porportioned tusk aside and jumps the female anyway? Has this study been adjusted for the availability of fodder?

I saw in a documentary recently that there are more elephants being born without tusks at all. The ones without tusks are especially nasty -- as if bad temperament were a compensation for lack of tusks. If true, this would be another example of natural selection at work. The gene for "no tusks" is only viable if it goes along with heightened aggression; otherwise, the animal has no chance of passing on its genes.

 

[Ocelot]

Yes I'm familiar with the detusked elephants
The creationist will cite this as Micro Evolution, graciously concede that such breeding occured, as they do with the peppered moth and domesticated animals but then claim that Macro Evolution has not been observed.

As such the Apple eating Hawthorn fly, and bactieria evolving antibiotic resistance or the ability to eat off nylon are better weapons in the arsenal of the rationalist.

 

[this charming man]

I choose the title "More evolution in our lifetime" because I feel that this is an example natural selection. Yes, there is micro-evolution such as insects becoming immune to pesticides, but this took a bit longer.

These elephants were not bred by humans to have certain characteristics; this happened naturally in the wild, so I would say it is a bit different than making a dog with hypo-allergenic hair and a sweet disposition.

 

[steenkh]

These elephants were not bred by humans to have certain characteristics; this happened naturally in the wild, so I would say it is a bit different than making a dog with hypo-allergenic hair and a sweet disposition.

I do not think there is any difference from what happens "in the wild" and what happens in farms when humans are actively selecting some animals from others. In the farm we might kill all cows that give too little milk, and in the wild we kill all elephants with large tusks. Same thing.

Except, of course, that in the farm we select with the intention of altering the characteristics, and in the wild, the alteration happens against our intentions.

 

[this charming man]

snip

Except, of course, that in the farm we select with the intention of altering the characteristics, and in the wild, the alteration happens against our intentions.

Do you agree that there is a difference between purposeful/intentional breeding and Natural Selection?

On a side note I never understood the banana argument made by creationists; do they not realize today's bananas are a result of human engineering, and they are not self-reproductive? A wild banana is full of seeds, and it is small and "ugly"; some, I think, are not even edible; are there even wild bananas anymore?

 

[steenkh]

Do you agree that there is a difference between purposeful/intentional breeding and Natural Selection?

When humans are doing the selection, I am not sure that there is a difference.

 

[this charming man]

When humans are doing the selection, I am not sure that there is a difference.

Fair enough; however, I think there is a difference between Intentional human breeding and flora/fauna adapting to its environment and the actions happening in said environment.

 

[Jimbo07]

The distinction is often made between artificial and natural selection. There is a conflict of world views here.

If humans are regarded as animals, then there is only natural selection. The tumblers in the lock fall into place.

If you believe that humans are somehow different in kind from the animals, then you have some mental gymnastics ahead...

 

[Cuddles]

Fair enough; however, I think there is a difference between Intentional human breeding and flora/fauna adapting to its environment and the actions happening in said environment.

How can there be a difference? Intentions are irrelevant. All that matters is what happens to the organisms. If elephants with smaller tusks survive more than elephants with big tusks, smaller tusks will evolve. It doesn't make any difference if the ones with bigger tusks are being hunted to make pianos or just keep catching them on trees, all that matters is that there is a selective pressure for smaller tusks.

The important point is that humans are part of the environment. A selective pressure caused by humans is every bit as natural as a selective pressure caused by cats with nasty, pointy teeth.

 

[this charming man]

How can there be a difference? Intentions are irrelevant. All that matters is what happens to the organisms. If elephants with smaller tusks survive more than elephants with big tusks, smaller tusks will evolve. It doesn't make any difference if the ones with bigger tusks are being hunted to make pianos or just keep catching them on trees, all that matters is that there is a selective pressure for smaller tusks.

The important point is that humans are part of the environment. A selective pressure caused by humans is every bit as natural as a selective pressure caused by cats with nasty, pointy teeth.

That is exactly my point. I make the distinction when farmers force tomatoes to grow plump and juicy, or a when a rancher selects only the finest steer to breed. I do not consider that natural selection. That is completely controlled by humans. The insect, moth, and elephant examples are the non-human animals reaction to what is happening; they are evolving to survive.

 

[CapelDodger]

That is exactly my point. I make the distinction when farmers force tomatoes to grow plump and juicy, or a when a rancher selects only the finest steer to breed. I do not consider that natural selection. That is completely controlled by humans. The insect, moth, and elephant examples are the non-human animals reaction to what is happening; they are evolving to survive.

I'm pretty much with Jimbo on this. For instance, how do you rate the fungi that leaf-cutter ants farm in their nests? They don't exist in the wild, they've been selectively bred. The only difference is "intention", and since we have that ability I think we make too much of it.

The earliest selection by humans was, I'm sure, entirely accidental - just as the selection for untusked elephants apparently has been.

 

[this charming man]

Perhaps I am not eloquent enough to make my point; however, I think we are all saying the same thing.

In my mind, I differentiate between purposeful breeding and nature taking its course; this includes human interference.

Elephants going smaller tusks b/c of poaching = natural selection
Seedless watermelons/the perfect beef steer = human breeding

To me, those are completely different situations.

 

[Jimbo07]

I'm pretty much with Jimbo on this.

Good. Cuz if ya ain't fer me, y'er agin' me.

The earliest selection by humans was, I'm sure, entirely accidental - just as the selection for untusked elephants apparently has been.

I differentiate between purposeful breeding and nature taking its course; this includes human interference.

Not me... and it gets more (or less, actually) complicated in my worldview! The hangup seems to come with assigning a non-natural specialness to humans.

I got into the snarl by asking myself, "where does nature end?" For most people, there seems to be a self-evident division between artificial and natural. I can't see the line. Clearly, my coffee cup is artificial. However, does a leafless stick count? There is some level of artifice required, some minimum number of steps, perhaps, but I don't know it. I heard a speaker on the radio once who (although I disagreed with her) had the good grace to define how she was using the word 'natural' at the beginning of her speech.

For me, all of the pieces fall into place when I simply assume that everything's natural!

 

[CapelDodger]

Perhaps I am not eloquent enough to make my point; however, I think we are all saying the same thing.

In general, perhaps, but inevitably (in these parts) the focus shifts to detail. At some level of detail Jimbo and I will have a falling out, and I'm as armed as he is against that day . That's in the nature of humans.

In my mind, I differentiate between purposeful breeding and nature taking its course; this includes human interference.

Elephants going smaller tusks b/c of poaching = natural selection
Seedless watermelons/the perfect beef steer = human breeding

To me, those are completely different situations.

Fair enough. To me, the difference is a detail in a much grander scheme of things. Humans do what humans do because it's in their nature. Leaf-cutter ants do what they do because it's in their nature. Humans do it in (relatively) small numbers by intention, but with little regard to the Law of Unintended Consequences. Leaf-cutter ants do it (in vastly larger numbers) without intention. We've been at it for half a million years or so, the ants for twenty-odd million (and there are twenty-odd species of them, as opposed to one surviving species of Homo).

The distinction is anthropocentric. If we outlive leaf-cutters maybe there's something in that, but it's yet to proved. And frankly speaking, our prospects don't look good.