Observable Natural Selection

[A_Wanderer]

One more of the many cases that supposedly don't exist

An international team of researchers has documented a remarkable example of natural selection in a tropical butterfly species that fought back - genetically speaking - against a highly invasive, male-killing bacteria.

Within 10 generations that spanned less than a year, the proportion of males of the Hypolimnas bolina butterfly on the South Pacific island of Savaii jumped from a meager 1 percent of the population to about 39 percent. The researchers considered this a stunning comeback and credited it to the rise of a suppressor gene that holds in check the Wolbachia bacteria, which is passed down from the mother and selectively kills males before they have a chance to hatch.

"To my knowledge, this is the fastest evolutionary change that has ever been observed," said Sylvain Charlat, lead author of the study and a post-doctoral researcher with joint appointments at the University of California, Berkeley, and University College London. "This study shows that when a population experiences very intense selective pressures, such as an extremely skewed sex ratio, evolution can happen very fast."

Charlat pointed out that, unlike mutations that govern such traits as wing color or antennae length, a genetic change that affects the sex ratio of a population has a very wide impact on the biology of the species.

It is not yet clear whether the suppressor gene emerged from a chance mutation from within the local population, or if it was introduced by migratory Southeast Asian butterflies in which the mutation had already been established.

"We'll likely know more in three years' time when the exact location of the suppressor gene is identified," said Charlat. "But regardless of which of the two sources of the suppressor gene is correct, natural selection is the next step. The suppressor gene allows infected females to produce males, these males will mate with many, many females, and the suppressor gene will therefore be in more and more individuals over generations."

Charlat worked with Gregory Hurst, a reader in evolutionary genetics at University College London and senior author of the paper. Descriptions of all-female broods of H. bolina date back to the 1920s, but it wasn't until 2002 that Hurst and colleagues first identified Wolbachia bacteria as the culprit behind the distorted sex ratio.

"We usually think of natural selection as acting slowly, over hundreds or thousands of years," said Hurst. "But the example in this study happened in a blink of the eye, in terms of evolutionary time, and is a remarkable thing to get to observe."

link

It isn't a revolutionary finding since population dynamics is investigated quite a bit but it's still cool.

[deep]

I heard that story on the radio earlier.



How do we know that God just didn't create a new kind of butterfly (The tenth one)?




all this gene-talk is just a bunch of gobbledy goop to hurt our beliefs

[Caroni]

Thanks for the article, I can´t believe I´m finding something about evolution on interference

I won´t comment because I really don´t want to start a discussion about evolution and God and etc... Do you know how hard is to be a Catholic biologist?

[Ormus]

Originally posted by Caroni
I won´t comment because I really don´t want to start a discussion about evolution and God and etc... Do you know how hard is to be a Catholic biologist?

Is Catholicism much more conservative and creationist where you live? Because here, Catholicism and evolution are quite compatible. My Catholic HS taught nothing but evolution in biology class!

[Caroni]

Originally posted by Ormus


Is Catholicism much more conservative and creationist where you live? Because here, Catholicism and evolution are quite compatible. My Catholic HS taught nothing but evolution in biology class!

Yeah, kind of, at least in my faculty the Catholic professors are very openminded

[A_Wanderer]

Originally posted by Caroni
Thanks for the article, I can´t believe I´m finding something about evolution on interference

I won´t comment because I really don´t want to start a discussion about evolution and God and etc... Do you know how hard is to be a Catholic biologist?

I know a Catholic palaeo student, as well as a nutbar Protestant one but I maintain being an obsessive and passionate atheist is better than either for science

[Caroni]

Probably, but there´s more than Science in this life and certainly fails miserably to proof a lot of things

[BonosSaint]

Wanderer, I'm curious as to your approach towards the soft sciences (other than the parts of them that can result in hard data) and humanities. (I'll leave theology out of it for both of our sakes)

[A_Wanderer]

I think that the material world is in principle if not in practice reducable to rational explanation, I don't think that we can ever hold solutions and complete understanding but I do think that however far we delve it can always be based on reality. Now this is not mutually exclusive to some very strange answers in terms of the nature of reality (basically any physics since the turn of last century).

But we are social organisms and understanding eachother is beyond the scope of analysing every thought process of every person from the neuron up, it demands a different approach. The humanities can inform an understanding of human behaviour, putting events into their proper context, producing pieces that appeal to our minds; I think that art and the capacity to appreciate it is an artifact of conciousness and that life is better for it, should we one day discover the mechanisms in the human brain that grants this appeal it couldn't diminish it.

I find the history of scientific discovery and the philosophy of science to be two areas with tremendous overlap (and an area that I find interesting - I have a history book on continental drift that presents the development of the theory with equal parts sociology and science, engaging and informative), I think that Stephen Jay Gould was right in proposing that religion and sciences are nonoverlapping magisteria, in that they deal with different things and can't truly conflict (although conflicts still do occur). This can be extended to some of the humanities but there are definitely areas where understanding the development of scientific ideas demands a humanaties based apporach to their origin and the people that contributed, in those cases it isn't so much science and humanities mixing rather having them inform eachother.

Both science and humanities demand sharp minds, they both demand ingenuity and can improve and understanding or appreciation for the world. I find myself as mentally aroused by palaeontology as no doubt a poet is by wordplay, I get to see how far I can push that interest later on but in principle I don't think that either is inherently more useful - just in different domains.

Theology is still a product of humanity, treating it to literary criticism and historical analysis does more to expose it for what it's worth (for better or worse) than scientific investigation can.

As far as the nature of my own atheism and the way that I think, it would be fair to say that I don't see the need for God in explanation as a tremendous ammount of the evidence can be explained better without it and that which cannot isn't within the scope of investigation (yet). The big issues like the origin of man, the rising of the sun, the formation of the Earth and the age of the Earth and to an extent the universe have been settled (until of course a better explanation can come along and explain the evidence better) and there is no guiding supernatural power. It isn't impossible that there is a God but if such an entity exists/existed then it would probably be the God of Spinoza rather than any petty interventionist deity. If and when the evidence points towards any higher power perhaps then there is something to consider or worry about but until that day comes I find the real world more engaging.

I am trying to improve my cultural literacy, and I suspect it pays off when dealing with other people, and it provides a decent enough distraction.

[BonosSaint]

I grew up with a stronger bent toward the humanities than I did toward science. I wasn't sure whether that was where my interests naturally lay or whether I always got stuck with the bad science teachers and the good humanities teachers. Anyway, by the time I got to college, I was dreadfully behind and intimidated by science. (The absolute humorous contempt my chemistry for non-science majors--"chemistry for poets"--professor had amused the hell out of me. "We study electrons because they're so cute." lol. That was his actual introductory lecture. God, he hated being stuck with our class, I think, but he treated us kindly.)

I don't think I gained much appreciation for science until young adulthood when I could begin to see the wonder of it and the connection with the way I thought anyway. I was always an observer, capable of being passionately dispassionate even when I was intensely involved. I would suspect it was astronomy more than anything else that drew me back in. I'm not skilled at science, but I have more of a sense of wonder about it, more curiosity so I've always appreciated your mini-seminars and have enjoyed some of the books you've recommended.

This is a difficult forum in which to discuss things, sometimes. I most always looked at the concept of God from the basis of humans, fascinated more by the process of the creation by man of a god than the god itself (and certainly more than than doctrine, dogma and the supernatural end of it). I don't study religions (most of them bore me to tears, which is the cardinal sin in my book) and have no interest in them. But I do have an interest in the psychological construct of a god concept. It is almost as if there is belief man can understand his humanity only by pitting himself against a god even when he does not believe in that god. It is a theme that courses throughout literature (English major).

And I am interested in finding out the reason why. I certainly don't believe some god is calling to us. I'm not sure that I completely accept your take that it is fear of death or a stopgap for the questions we have yet to have answered, although I think those are elements of it. There's a primal feel about it that has nothing whatsoever to do with god. I have theories about it, but none of them satisfy me completely.

I would call myself agnostic--allowing the possibility of a god without accepting the probability of one. The existence of a god interests me less than what humanity has done to create one.