Is Evolution Predictable? By Elizabeth Pennisi

Is Evolution Predictable? | Science | AAAS

If the clock rewound, would organisms evolve the same way they did before? Humble stick insects may hold the answer to that long-running question in biology. Through studies of these bugs, whose bodies match the leaves the insects live on, researchers have found that although groups of the bug have evolved similar appearances, they achieved that mostly via different changes in their DNA. “I think it says that repeatability of evolution is very low,” says Andrew Hendry, an evolutionary biologist at McGill University in Montreal, Canada, who was not involved with the work.

A few studies have suggested that, when exposed to the same environmental conditions, organisms evolve in the same way. As glaciers have receded, for example, a tiny marine fish called the stickleback has invaded many lakes and rivers, and in each spot, they became sleeker with less body armor. Other researchers have looked beyond changes in behavior or physical features for “parallel evolution” in the genes, finding, for instance, that different insects alter the same DNA to help them feed on toxic plants. Yet critics have argued that these examples represent the exception and that evolution is not really predictable because too many chance events can knock it off course.

So Patrik Nosil, an evolutionary biologist at the University of Sheffield in the United Kingdom, turned to a stick insect called Timema cristinae. In many places in California, this species has split into two forms, or ecotypes, on a hillside. One form is wide and lives on a wide-leaf plant; the other is narrow, with a stripe down its back, and lives on a plant with narrow leaves. Nosil and his colleagues sequenced the genomes of dozens of individuals of each ecotype from multiple hillsides to assess the genetic differences that arose to make them specialized for their particular host plant.

They discovered many genetic differences between the ecotypes. Yet to their surprise, they found that, even in stick insects that looked the same but were from different places, only 17% of their DNA had changed in the same way.  That suggests, Nosil and his colleagues report online today in Science, that although some evolution in the genes leading to host specialization is predictable, a lot of the changes are random.

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“Interfaith Thanksgiving Services ” By F. Sheikh

Happy Thanksgiving to all participants.

Yesterday I had the pleasure to attend Nyack Community Interfaith Thanksgiving Service arranged by Interfaith Clergy Association of Nyack. The Grace Church Community hall was packed with attendees. It was a festive atmosphere with show of respect and love for followers of all faiths and emphasis by all speakers on standing for each other when anyone is under attack and is being discriminated. After attending such a meeting, one realizes the importance of participating in such events and building bridges with community so that you do not feel alone when you are under attack. Azeem Farooki  has been doing a great job of participating in such outreach programs on behalf of Muslim community, but it needs more participation from Muslim community members to have a real impact. This event was also attended by Dr. Nasik Elahi, Dr, Bhanna, Mr. and Mrs Farooq Moattar.  See below some pages of pamphlet of the event. Page 4 shows Quran reading. It was done by Azeem Farooki with a short speech emphasizing love for our great country which has no place for bigotry, racism, and hatred.       

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posted by F. Sheikh

Are Majority Of Cancers Matter Of Bad Luck?

Bad luck and cancer: A science reporter’s reflections on a controversial story

We reporters—or this one, at any rate—often fail to anticipate which stories will grip readers and which will quickly fade into oblivion. Given that, perhaps I shouldn’t have been surprised that a story I saw off to the printing press in the lull between Christmas and New Year’s engendered more comments than any other I’ve written.

The piece, which appeared online with the headline “The simple math that explains why you may (or may not) get cancer” (and in the magazine’s News section with the headline “The bad luck of cancer”), described a paper published in the 2 January issue of Science. As I and many other journalists explained, the study suggested that simple “bad luck”—random mutations accumulating in healthy stem cells—could explain about two-thirds of cancers, exceeding the risk conferred by environmental and genetic factors combined. One message was that some cancers could not be prevented and that detecting them early was key to combating them.

Readers wasted little time in skewering the authors, mathematician Cristian Tomasetti and cancer geneticist Bert Vogelstein of Johns Hopkins University in Baltimore, Maryland. Their statistics were faulty, some argued; they included many rare cancers and left out several common ones. Earlier today, the International Agency for Research on Cancer, the cancer arm of the World Health Organization, put out an unusual press release stating it “strongly disagrees” with the report. The agency said that “nearly half of all cancer cases worldwide can be prevented.” It charged that the authors’ push for early detection “if misinterpreted … could have serious negative consequences from both cancer research and public health perspectives.”

Reporters, if anything, fared worse. “Please, journalists, get a clue before you write about science,” pleaded an irate column in The Guardian, co-authored by an evolutionary biologist who goes by the Twitter handle @GrrlScientist and statistician Bob O’Hara at the Biodiversity and Climate Research Centre in Frankfurt, Germany.

Given the furor, I wondered: Had I gotten it wrong? Had the authors? Answering these apparently straightforward questions proved surprisingly difficult, exposing the challenges that come with communicating science, and the desire by scientist-authors and reporters to streamline the story they’re trying to tell.

I began with my own story, working backward to the science that spawned it. I’d written that the theory of random mutations in stem cells “explained two-thirds of all cancers.” Immediately, I knew that I had written part of that sloppily, to put it generously: The study didn’t include all cancers. In fact, it didn’t include two of the most common, prostate and breast, because the authors weren’t able to pin down the size of the stem cell compartment or the frequency of stem cell divisions in those tissues. Although my piece subsequently noted the number of cancer types in the study, I should have stressed the omissions early on.

Still, was “two-thirds” referring to the number of cases of cancers the study did include, as I and other journalists had suggested—or to something else? Journalists like numbers that abridge a study down to a bullet point. I’d wondered immediately if this two-thirds finding might be one such nugget. Tomasetti had explained to me in a lengthy interview that “if you go to the American Cancer Society website and you check what are the causes of cancer, you will find a list of either inherited or environmental things. We are saying two-thirds is neither of them.” I’d run the text of my “two-thirds” sentence by him prior to publication and he had had no objections (he had other clarifications).

Last week, we spoke again. Tomasetti had received more than 200 e-mails. Parents of children who had died of cancer were grateful that it might have occurred entirely by chance, suggesting that there was nothing they could have done. Biologists and statisticians were disputing his conclusions or simply surprised that so much of cancer might be random.

“We did not claim that two-thirds of cancer cases are due to bad luck,” Tomasetti told me gently. What the study argued, he explained, was that two-thirds of the variation in cancer rates in different tissues could be explained by random bad luck (a point made by others). What exactly did that mean, I wondered? Tomasetti, chatting by phone, had me draw some graphs to help me understand. By the end of the hour, I still wasn’t sure I grasped the essence.

Tomasetti was sympathetic. “There are lots of scientists that need clarification” on this paper, he said, along with some statisticians. He was busy preparing a technical report with additional details, and Johns Hopkins had just put out a press release explainer. “I honestly feel—and that’s what I told the BBC, and you can definitely quote me on this—overall, the reporters who interacted with us made a very honest and sincere effort to be as accurate as possible.”

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Science doesn’t rely on luck, but success in science can’t do without it

What – if anything – can be learned from studying the career trajectory of successful scientists? To determine whether predicting trends in future scientific breakthroughs might be possible by examining past performance, an international team led by the physicist Albert-László Barabási at Northeastern University in Boston studied the careers of thousands of scientists across numerous disciplines, charting their most cited papers to gauge impact as a measure of success. While the study reaffirmed previous findings about creativity that show high levels of productivity early in scientists’ careers, there was a surprise in the data. When timing of productivity was removed, the research revealed that impact in a scientist’s career is random, and not correlated to experience. In short, success is a complex function of ability, productivity and luck. The full paper is available at Science magazine.

click for original paper

Video by Nature

Visualisation: Mauro Martino

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