Real Science Friday: Stars in Galaxy Bulges "Look Too Perfect"

[Stripe]

I look at piles of rocks at the bottom of cliffs with the assumption of gravity, too. For the same reasons.

When you find someone prepared to argue that gravity does not explain what we see, let us know. :thumb:

Only a creationist could consider relying on evidence to be "irrational."

You do not rely upon evidence, you rely upon your explanation and use it as if it were evidence.

The evidence is that asexually reproducing organisms are more likely to be badly affected by disease. Your explanation is that evolution selected those organisms to survive by reproducing this way that are not susceptible to disease. The reverse might well be the correct explanation instead. The reverse is organisms are not susceptible to disease because they are asexual.

 

[The Barbarian]

Barbarian chuckles:
I look at piles of rocks at the bottom of cliffs with the assumption of gravity, too. For the same reasons.

When you find someone prepared to argue that gravity does not explain what we see, let us know.

Seeing as no one here is peddling a new religion that is incompatible with gravity, that seems unlikely, doesn't it?

Barbarian observes:
Only a creationist could consider relying on evidence to be "irrational."

You do not rely upon evidence, you rely upon your explanation and use it as if it were evidence.

That's a testable assertion. Go back and see what I do, when I disagree. If I usually make an unsupported assertion, you're right. If I usually cite evidence, you're wrong.

Barbarian observes:
The evidence is that asexually reproducing organisms are more likely to be badly affected by disease.

Your explanation is that evolution selected those organisms to survive by reproducing this way that are not susceptible to disease.

No. Natural selection tends to favor sexually-reproducing organisms where parasitism and disease organisms are common. Quite a different thing.

The reverse might well be the correct explanation instead. The reverse is organisms are not susceptible to disease because they are asexual.

The problem for you is, as usual, the evidence. We find that asexually-reproducing populations tend to be more vulnerable to disease.

 

[Stripe]

That's a testable assertion. Go back and see what I do, when I disagree.

Typical. This is not about you disagreeing with anything. This is about you presenting your explanation as if it is evidence.

Perhaps you're just not capable of understanding that facts need to be presented within a rationally constructed argument in order to use them as evidence. :idunno:

We find that asexually-reproducing populations tend to be more vulnerable to disease.

In fact.

But it's how you explain the origins of this fact that is what makes your discourse irrational.

 

[Bob Enyart]

(One small example: Most animals reproduce sexually, yet Darwinism would never predict sexual reproduction.)

In fact, Darwinian theory can accurately predict which sorts of organisms will reproduce asexually.
Turns out, asexual reproduction works better for organisms not challenged much by parasites or diseases. For the rest of us, sexual reproduction works better to spread new resistance strategies and to keep old ones handy for future use.

Barbarian, the point was that evolution theory would not predict the existence of asexual reproduction. Creationists concur that there are benefits to sexual and asexual reproduction, and that there are good reasons for both. Since pointing out good reasons for sexual reproduction is something that both sides of the debate do equally, it is arbitrary for you to use that as fulfillment of an alleged prediction (postdiction ??) of evolution. So I think the point stands. The theory of evolution would NEVER predict that sexual reproduction would arise, especially considering all the wild complexity involved.

-Bob Enyart

 

[Bob Enyart]

My husband is now hooked on this show. He went to kgov.com yesterday and listened to this show.

IK, please give him my regards. And I told Fred that we have a new listener! (Hey, we celebrate these things... one friend at a time

-Bob Enyart
Real Science Friday.com

 

[The Barbarian]

Barbarian, the point was that evolution theory would not predict the existence of asexual reproduction.

More precisely, it predicts which sorts of organisms should have one or the other. And it does a pretty good job of that.

Creationists concur that there are benefits to sexual and asexual reproduction, and that there are good reasons for both. Since pointing out good reasons for sexual reproduction is something that both sides of the debate do equally, it is arbitrary for you to use that as fulfillment of an alleged prediction (postdiction ??) of evolution.

The difference, of course, is that evolutionary theory can explain why some organisms are asexual and others not. Where rapid reproduction in relatively constant environments is needed, asexual reproduction has an advantage. Where there is much change, and rapid reproduction is not needed, then sexual reproduction is better.

One odd case, that didn't make sense, was whiptail lizards, which should not be asexual, even though at least one species is. Then the reason became clear:

The new research by Baumann and his team reveal that these lizards maintain genetic richness by starting the reproductive process with twice the number of chromosomes as their sexually reproducing cousins. These celibate species resulted from the hybridization of different sexual species, a process that instills the parthenogenetic lizards with a great amount of genetic diversity at the outset. And the researchers found that these species could maintain the diversity by never pairing their homologous chromosomes (as sexual species do by taking one set of chromosomes from each parent) but rather by combining their sister chromosomes instead. "Recombination between pairs of sister chromosomes maintains heterozygosity" throughout the chromosome, noted the authors of the study, which was led by Aracely Lutes, a postdoctoral researcher in Baumann's lab.

This discovery, which had until now been unconfirmed in the reptile world, means that "these lizards have a way of distinguishing sister from homologous chromosomes," Baumann says. How do they do it? That's something the group is now investigating.
http://www.scientificamerican.com/article.cfm?id=asexual-lizards

So I think the point stands. The theory of evolution would NEVER predict that sexual reproduction would arise, especially considering all the wild complexity involved.

Probably wouldn't have predicted giraffes, either. But then physics wouldn't have predicted superconductivity until related phenomena were discovered. The important thing is that science can look at the evidence, come up with explanations, test them, and then use them to understand other things in nature.

It's not magic. It's just a way of understanding the world. And it works better for that, than anything else we can do.

 

[Stripe]

More precisely, it predicts which sorts of organisms should have one or the other. And it does a pretty good job of that.

More precisely, the reproductive differences define what sort of features the population will have. As usual, the evolutionists will assert a causal relationship and use it as evidence for their evolution when the story is their explanation.

The difference, of course, is that evolutionary theory can explain why some organisms are asexual and others not. Where rapid reproduction in relatively constant environments is needed, asexual reproduction has an advantage. Where there is much change, and rapid reproduction is not needed, then sexual reproduction is better.

Or else populations asexual populations tend to reproduce rapidly and sexual less so. And certain kinds might respond to a change in environment and switch between the two methods of reproduction.

Probably wouldn't have predicted giraffes, either. But then physics wouldn't have predicted superconductivity until related phenomena were discovered. The important thing is that science can look at the evidence, come up with explanations, test them, and then use them to understand other things in nature.

Suddenly, when it suits him, Barbarian thinks science can do things. :chuckle:

 

[The Barbarian]

Typical. This is not about you disagreeing with anything. This is about you presenting your explanation as if it is evidence.

But the evidence does show this to be true:

Genetic diversity and disease control in rice
Nature 406, 718-722
Youyong Zhu, Hairu Chen, Jinghua Fan1, Yunyue Wang1, Yan Li1, Jianbing Chen1, JinXiang Fan2, Shisheng Yang3, Lingping Hu4, Hei Leung5, Tom W. Mew5, Paul S. Teng5, Zonghua Wang5 & Christopher C. Mundt5,6
Crop heterogeneity is a possible solution to the vulnerability of monocultured crops to disease1, 2, 3. Both theory4 and observation2, 3 indicate that genetic heterogeneity provides greater disease suppression when used over large areas, though experimental data are lacking. Here we report a unique cooperation among farmers, researchers and extension personnel in Yunnan Province, China—genetically diversified rice crops were planted in all the rice fields in five townships in 1998 and ten townships in 1999. Control plots of monocultured crops allowed us to calculate the effect of diversity on the severity of rice blast, the major disease of rice5. Disease-susceptible rice varieties planted in mixtures with resistant varieties had 89% greater yield and blast was 94% less severe than when they were grown in monoculture. The experiment was so successful that fungicidal sprays were no longer applied by the end of the two-year programme. Our results support the view that intraspecific crop diversification provides an ecological approach to disease control that can be highly effective over a large area and contribute to the sustainability of crop production.

Perhaps you're just not capable of understanding that facts need to be presented within a rationally constructed argument in order to use them as evidence.

Surprise. Did you really think I couldn't back it up? C'mon, this has been known for well over a hundred years.

Barbarian observes:
We find that asexually-reproducing populations tend to be more vulnerable to disease.

But it's how you explain the origins of this fact that is what makes your discourse irrational.

At least one species of whiptail lizards, for example, recently became asexual. Which was a challenge for scientists, because that should have made them vulnerable to disease, because of the loss of variation.

And then it was discovered that they were quadraploid, and by not sorting the chromosomes, were maintaining a high level of genetic diversity. And the theory was again confirmed.

Are you beginning to suspect that not knowing what you're talking about, is causing you problems, Stipe?

Probably not. lain:

 

[Stripe]

But the evidence does show this to be true:

Typical evolutionist. Use the general term "this" to import your own idea instead of responding to what I said.