Mysterious Mammalian DNA Survives for Eons
Science | Thu, Oct 9, 2008 at 6:05:39 pm PDT
A fascinating discovery by scientists investigating the mammalian genome: Mysterious DNA Found to Survive Eons of Evolution.
Scientists have discovered mystery snippets of mammal DNA that have survived eons of evolution and yet have no apparent purpose. The finding reveals just how much we don’t know about the secrets hidden in our genome and that of other animals.
Most genes change throughout evolution via mutations; useless ones eventually get weeded out of the population while the helpful modifications take hold. However, about 500 regions of our DNA - the body’s instruction code made up of base pairs of molecules - have apparently remained intact throughout the history of mammalian evolution, or the past 80 million to 100 million years, basically free of mutations.
“Mutations are introduced into these regions just as they are everywhere else, but they’re swept out of the genome much more quickly,” said researcher Gill Bejerano, professor of developmental biology and computer science at Stanford University. “These regions seem to be under intense purifying selection - no mutations take hold permanently.”
And what’s more, many of those sequences do not appear to code for any obvious function, or phenotype, in the body. Researchers suspect they do serve an important purpose, but have yet to figure out exactly what that purpose is. (These sequences are not the same as non-coding or “junk” DNA, for which no function has been identified. Also, most junk DNA has not been conserved for eons like these segments.)
Ultraconserved regions
The researchers call these mystery snippets “ultraconserved regions,” and found that they are about 300 times less likely than other regions of the genome to be lost during the course of mammalian evolution. Bejerano and his graduate student Cory McLean detailed the finding in the Oct. 2 issue of the journal Genome Research.
The fact that these segments haven’t been weeded out by natural selection implies that they serve an important function in mammals. Yet mice in the lab bred to lack these DNA strands appear healthy and don’t seem to be missing any vital genes.
Wondering if the odd results were simply some fault of the lab experiment, and perhaps the mice really weren’t as well off as they seemed, the researchers investigated whether any other mammals were also blithely living without these regions.
Amazingly, they found that was not the case.
Tech Note: Javascript Reboot
Science | Thu, Oct 9, 2008 at 4:41:50 pm PDT
It’s time to reload the page, as we’ve made structural changes to the HTML and Javascript code to make comments pages significantly smaller and less complex, which should help keep the hamsters from going totally insane.
VDH: Line of the Day
Opinion | Thu, Oct 9, 2008 at 3:04:21 pm PDT
Victor Davis Hanson gets the line of the day: What Is Wisdom?
Perhaps salmon fishing or moose-hunting might have been of value in reifying the more abstract wisdom found in Niebuhr.
Iowahawk: ACORN Files Voting Rights Suit on Behalf of Imaginary-Americans
Humor | Thu, Oct 9, 2008 at 2:33:13 pm PDT
Breaking from the Iowahawk News Cartel: ACORN Files Voting Rights Suit on Behalf of Imaginary-Americans.
ST. LOUIS - Attorneys for the voting registration organizations ACORN and Project Vote filed an anti-discrimination voting rights suit in the U.S. Federal District court this morning, alleging the United States government is involved in “a widespread, systematic effort to disenfranchise Imaginary-Americans and deprive them of access to polls.”
“Participation in our electoral process is a fundamental right, and the foundation of our democracy,” said ASDF ASDFG, a spokesperson for the National Association for the Advancement of Imaginary People, one of the groups named as plaintiffs in the class action. “We will not be silent when government denies people access to the polls on the basis of color, or sex, or existential status.”
Financial Crisis Watch
Business | Thu, Oct 9, 2008 at 1:04:16 pm PDT
If you thought the market was in free fall earlier this week, well... we apparently haven’t seen the bottom yet. The Dow is at -629 as we write, lowest point since 2003...
Obama's Disingenuous Statement on William Ayers
Politics | Thu, Oct 9, 2008 at 11:49:46 am PDT
Barack Obama’s latest statement on his association with former Weather Underground is a perfect example of his slippery rhetoric: Obama: McCain Scoring ‘Cheap Political Points’.
“Why don’t we just clear it up right now,” Obama told ABC News’ Charlie Gibson in an exclusive interview for World News. “I’ll repeat again what I’ve said many times. This is a guy who engaged in some despicable acts 40 years ago when I was eight years old. By the time I met him, 10 or 15 years ago, he was a college professor of education at the University of Illinois . . . And the notion that somehow he has been involved in my campaign, that he is an adviser of mine, that . . . I’ve ‘palled around with a terrorist’, all these statements are made simply to try to score cheap political points.”
Notice: in Obama’s “clarification,” the only things he denies are accusations that no one has made. No one has claimed that William Ayers is involved in his current campaign (although Obama did get his political start at an event held in Ayers’ living room), and no one has claimed that Ayers is an current adviser to Obama.
He’s denying straw men—but not denying any of the factual claims that have been made.
And he cleared up nothing at all. This is the same tactic he used to defend and excuse his association with Rev. Jeremiah Wright, until Wright’s embarrassing public statements forced Obama to renounce him.
Ayers, meanwhile, has sequestered himself and is not talking to anyone. He won’t make the same mistake Wright made, and mouth off in public—although that didn’t seem to worry him much before Obama was running for president.
The media sent teams of reporters to dig through Alaskan dumpsters to find dirt on Sarah Palin, but they’re completely uninterested in finding and interviewing William Ayers.
New McCain Ad: 'Ayers'
Politics | Thu, Oct 9, 2008 at 9:31:18 am PDT
UPDATE at 10/9/08 10:07:48 am:
The leftists are playing games at YouTube again. This video—from the campaign of a presidential candidate!—has now been flagged as “inappropriate” and you need to confirm your birth date before viewing. Amazing.
The Sayings of Obama
Politics | Thu, Oct 9, 2008 at 8:40:16 am PDT
John Hawkins has compiled a massive list of quotes by and about Barack Obama, from The One himself, wife Michelle, Joe Biden, Jeremiah Wright, Bill Ayers, and even Hillary Clinton: Barack Obama In Quotes Version 3.0.
