Poaching making China elephants evolve tuskless

[CFLarsen]

Poaching making China elephants evolve tuskless

Chinese elephants are evolving into an increasingly tuskless breed because poaching is changing the gene pool, a newspaper reported on Sunday.

Five to 10 percent of Asian elephants in China now had a gene that prevented the development of tusks, up from the usual 2 to 5 percent, the China Daily said, quoting research from Beijing Normal University.

"The larger tusks the male elephant has, the more likely it will be shot by poachers," said researcher Zhang Li, an associate professor of zoology. "Therefore, the ones without tusks survive, preserving the tuskless gene in the species."

Since only male elephants have tusks, there were now four female elephants for each male in China, up from the ideal ratio of two, the paper said.

Similar changes in elephant tusk development and sex ratios have been reported in Africa and India.
Source

Fascinating.

 

[Anders]

Fascinating.

Nah, not really. Just ordinary evolution. Perhaps a bit aided by humans.

Let see how long before our x-ian friends start to dismiss this as some different mechanism that is not evolution.

 

[clarsct]

I dunno, I find it pretty amazing.


Evolution in action where it can be seen. Marvelous process.


Yeah, I know, we see it on a small scale almost daily with bacteria and viruses..but it doesn't have the same IMPACT that this does.

I think it's cool.

 

[CFLarsen]

Re: Re: Poaching making China elephants evolve tuskless

Nah, not really. Just ordinary evolution. Perhaps a bit aided by humans.

Still fascinating.

Let see how long before our x-ian friends start to dismiss this as some different mechanism that is not evolution.

"Indirect breeding"? (If this catches on, I want royalties!!)

 

[Donks]

Re: Re: Poaching making China elephants evolve tuskless

Let see how long before our x-ian friends start to dismiss this as some different mechanism that is not evolution.

Can you not guess what could be said?
"That's not macro-evolution, it's micro-evolution. When the elephants turn into dogs, that'll be evolution.

 

[Anders]

Re: Re: Re: Poaching making China elephants evolve tuskless

Can you not guess what could be said?
"That's not macro-evolution, it's micro-evolution. When the elephants turn into dogs, that'll be evolution.

Too obvious…

But I'll be ready with my molecular biology knowledge should they try that.

 

[Paul C. Anagnostopoulos]

Anders said:
Too obvious…

So you think the Creationists and IDers are getting more subtle? We shall see.

~~ Paul

 

[neutrino_cannon]

Frankly I'm suprised the effects were noticible in this short a period of time. Elephants don't reproduce very quickly, so they must be under some terrible selective pressure!

 

[JR "BOB" Dobbs]

I've been hearing bits and pieces about this for a while now, and it has given me hope that this will keep these elephants from extinction. I was a meatcutter for many years at a local shop, and I would cut up deer that the locals would get during hunting season. I sure noticed that the racks were getting smaller over the years, but without population and gene samples, the assumption that the gene frequency is shifting is contaminated by too many other factors.

 

[Rolfe]

Well, just to be annoying, I'll point out that if the gene was already present in the population (which the article says it was), this isn't true evolution, it's just a shift of the gene pool.

I wonder what the inheritance of the tuskless state is?

A dominant gene is very easy to eliminate from a population, because the phenotype always displays the genotype. This is how the polydactly gene was eliminated from the show Maine Coon so quickly (of course, having done that, they now want it back....)

On the other hand, a recessive is difficult to eliminate, because it can be there in quite high prevalence without too many phenotypically obvious individuals.

Several breeds of cattle have been bred to be polled (no horns) by crossing out to the most similar polled breed that can be identified. Then, only the polled progeny are bred from, but bred to pure-bred individuals. After only five generations you have true-breeding polled cattle which are 15/16ths the original breed. Works because the polled gene is recessive, so it's quite easy to select out the horned gene.

If the gene pool is just shifting to a higher prevalence of tuskless elephants, it's not evolution by any usual definition of the term. But on the other hand if it gets to the point where the tusk gene is entirely eliminated, might that qualify? Any opinions?

Rolfe.

 

[clarsct]

Well, yeah. I was, perhaps incorrectly, thinking that was what was being seen. The gene for the tusk being 'phased out'. Of course, it isn't gone yet, but it would be interesting to see it go. Tusks evidently have some survival value, and it will be interesting to watch what other survival techniques are used and which are learned, and which passed on.

Call it a 'punctuation point'.

 

[Art Vandelay]

Well, just to be annoying, I'll point out that if the gene was already present in the population (which the article says it was), this isn't true evolution, it's just a shift of the gene pool.

So if a gene goes from 1% to 99%, that's not evolution, but going from 0% to .0001% is? Evolution is a shift in the gene pool.

If the gene pool is just shifting to a higher prevalence of tuskless elephants, it's not evolution by any usual definition of the term. But on the other hand if it gets to the point where the tusk gene is entirely eliminated, might that qualify? Any opinions?

So what qualifies as a "usual definition"? Because the scientific definition is the very one you reject. So to answer your question, the opinion of biologists is that it qualifies.

 

[Jyera]

2 wacky theories here.

1. Poaching elephants I supose is not a trival task for a single person. Perhaps the poachers as an organisation do refrian from poaching an elepant that has too short a tusk. Thus the elephants with tusk beyond a profitable length gets killed of faster systematically. While the young and shorter ones survives.

2. The Female elephants may be smarter than you think.
It may prefer a "better" looking male.

It was said that a person judges a face to be beautiful base on how common it is to him/her. The beauty queen's facial feature looks common. Not ugly, not unexpected. It is uncommon to have a lady with only one eye on the face, thus she will not be considered beautiful.

I guess the elephants population is getting more and more "shorter-tusk"-looking. Thus the female elephants are getting more exposed to the image of "shorter-tusk" male. And thus prefer to mate with a partner with shorter-tusk.

Sounds odd but I just post what pops into mind.

Feel free to critic these ideas but spare me.

 

[clarsct]

Jyera, I would comment on your ideas about beauty.

In all beauty, there is strangeness. You do not see beauty queens walking the street everyday, thus they are unusual. Their features tend to be symmetrical, but that is not to say ordinary. Most people's faces are slightly asymmetrical. The more out of line, the uglier, they are considered, as a general rule. Of course, these things were studied in humans, not elephants.

As for the poaching, mayhap. I really wouldn't know, but it sounds semi-plausible.

 

[Deetee]

Just to follow on from Rolfe's comments. I think she is correct in her assessment of what the creationists would say.

They insist on new genetic information being generated before they would contemplate the possibility of evolution occuring (the fact that there many examples of this happening that have actually been pointed out to them (but which they ignore) is another tale..).
Otherwise all you have is "variation" and "micro-evolution". One doesn't need to point to elephants losing tusks as a prime example of this in large animals - one only needs to look at selective breeding of pets to realise that variation within one species can range from chihuahuas to great danes. An uninformed observer might mark those 2 dogs down as being different species of animal, but they are not.

 

[Rolfe]

So if a gene goes from 1% to 99%, that's not evolution, but going from 0% to .0001% is? Evolution is a shift in the gene pool.

So what qualifies as a "usual definition"? Because the scientific definition is the very one you reject. So to answer your question, the opinion of biologists is that it qualifies.

Oh, really? I'll just go resign my Fellowship of the Institute of Biologists, then.

Rolfe.

 

[Soapy Sam]

Test case (reductio ad absurdum) :-
We line up all fertile , female elephants and shoot them.

Then we wait a hundred years and count the elephants.

Is this evolution?


Let's not get lost in the definition jungle. Evolution is change in a creature. It may be phenotype or genotype. It may be due to genetic drift. It may be driven by sexual selection. It may be indirect- eg rock drops on dinosaurs, primates evolve, humans evolve, Maine Coons evolve.
(Forcibly).

I can imagine a situation where the genotype of a creature changes dramatically over a long time, while the phenotype stays exactly the same. It's still evolution.

Whether shooting elephants is evolution by means of natural selection depends on what we choose to mean by "natural".

Are we allowed to say "Maine Coon" here, by the way?

 

[Rolfe]

So if a gene goes from 1% to 99%, that's not evolution, but going from 0% to .0001% is?

Since the latter involves the introduction of a new gene (therefore, mutation), then arguably, yes.

Are we allowed to say "Maine Coon" here, by the way?

Better ask Darat!

Rolfe.

 

[pgwenthold]

Oh, really? I'll just go resign my Fellowship of the Institute of Biologists, then.

Rolfe.

I find this "textbook" definition on the talkorigins website

"In fact, evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next."
- Helena Curtis and N. Sue Barnes, Biology, 5th ed. 1989 Worth Publishers, p.974

 

[BillHoyt]

Since the latter involves the introduction of a new gene (therefore, mutation), then arguably, yes.Better ask Darat!

Rolfe.

Uh-oh. Sorry, Rolfe, this is dead wrong. The definition is shifting allele frequencies. Period. Whether or not they are new is irrelevant. (Whether or not they are new, BTW, is almost always an unknown.)