New Orleans sinking faster than expected:
... The research, being published Thursday in the journal Nature, is based on new satellite radar data for the three years before Katrina struck in 2005. The data show that some areas are sinking - from overdevelopment, drainage and natural seismic shifts - four or five times faster than the rest of the city. And that, experts say, can be deadly.
'My concern is the very low-lying areas,' said lead author Tim Dixon, a University of Miami geophysicist. 'I think those areas are death traps. I don't think those areas should be rebuilt.'
For years, scientists figured New Orleans on average was sinking about one-fifth of an inch a year based on 100 measurements of the region, Dixon said. The new data from 150,000 measurements taken from space finds that about 10 percent to 20 percent of the region had yearly subsidence in the inch-a-year range, he said...
Wednesday, May 31, 2006
New Orleans will not be entirely rebuilt
It's looked for a while as though there was reluctance to rebuild on the lower parts of New Orleans. This may end the debate:
Molly Ivins: Enron's President Bush
Molly Ivins makes the populist case. It's a strong case these days. I liked the summary of the campaing contributions Enron and its execs made. Note the sum of the executive contributions (bolded by me):
WorkingForChange-The takeover is completeI like my campaign reform proposals better than Molly's generic appeal to public financing.
...The extent to which not just state legislatures but the Congress of the United States are now run by large corporate special interests is beyond mere recognition as fact. The takeover is complete. Newt Gingrich and Tom DeLay put in place a system in which it's not a question of letting the head of the camel into the tent -- the camels run the place.
It has all happened quite quickly -- in less than 20 years. Laws were changed and regulations repealed until an Enron can set sail without responsibility, supervision or accountability. The business pages are fond of trumpeting the merits of 'transparency' and 'accountability,' but you will notice whenever there is a chance to roll back any of New Deal regs, the corporations go for broke trying to get rid of them entirely.
I'm not attempting to make this a partisan deal -- only 73 percent of Enron's political donations went to Republicans. But I'll be damned if Enron's No. 1 show pony politician, George W. Bush, should be allowed to walk away from this. Ken Lay gave $139,500 to Bush over the years. He chipped in $100,000 to the Bush Cheney Inaugural Fund in 2000 and $10K to the Bush-Cheney Recount Fund.
Plus, Enron's PAC gave Bush $113,800 for his '94 and '98 political races and another $312,500 from its executives. Bush got 14 free rides on Enron's corporate jets during the 2000 campaign, including at least two during the recount. Until January 2004, Enron was Bush's top contributor.
And what did it get for its money? Ken Lay was on Bush's short list to be energy secretary. He not only almost certainly served on Cheney's energy task force, there is every indication that the task force's energy plan, the one we have been on for five years, is in fact the Enron plan. Lay used Bush as an errand boy, calling the governor of Texas and having him phone Tom Ridge of Pennsylvania to vouch for what swell energy deregulation bills Enron was sponsoring in states all over the country...
A diversity of minds: are humans less alike than we imagine?
Like everyone else who's worked with autistic children, I have a theory about autism. I have no data and no real expertise, so I'm free to speculate.
First of all, I think it's really not one thing. It's probably several disorders of brain development, largely arising from genetic and intrauterine effects, that manifest with a few common features and many atypical features.
That's not all that interesting, so I'll go further. I also think that what's common in autism is the brain's frantic efforts to adopt to being broken. So one or many things is/are going "wrong" (quotes are important) in brain development, but there are common compensatory mechanisms that still work. The developing brain is breaking and trying to repair itself -- all at the same time. Somethings get repaired well, some don't. Sometimes the result works -- but it works differently.
Temple Grandin's mind works differently. Grandin is a famous interlocutor for autistic persons. She has several books and essays out, including this one: My Mind is a Web Browser: How People with Autism Think. Grandin has since recognized that she's really describing how she thinks, and that not all autistic persons think the same way [1]. The point, however, is that she has an "alien" way to thinking. It doesn't work all that well most of the time, but it is well suited to certain types of problem solving. She is a visualization 'savant' [2], in a way that some autistic persons are numerical 'savants'. She has enough symbolic reasoning and language to be able to translate from her world of visualization to the more common world of language.
Variations in neurodevelopment resulting by "malfunction" and adaptation/healing, yielding diverse minds that function better in some environments, worse in others.
Remind you of anything?
Isn't that how natural selection works?
We think that humans haven't evolved much in the past few hundred thousand years because our bodies seem similar. We are creatures of the brain though. What if there's an adaptive advantage to a "flaky" neurodevelopmental process? Maybe there's a reason we have so many "malformed" brains. It's not only that brains are hard to make, but also that there's a species advantage to having diverse brains and minds being created - even if some individuals bear a heavy price for being maladapted to the common environment.
Perhaps if we truly understood the human mind, we would discover that we are much less alike than we think.
[1] Grandin is nothing if not definite, but she also changes her mind. It's an interesting trait, and very scientific in a way. Overgeneralizing from self to all is a classic autistic trait, and not uncommon in neurotypicals either.
[2] It would be interesting to see how well Grandin could talk to a dolphin, presumably they think in sonar.
First of all, I think it's really not one thing. It's probably several disorders of brain development, largely arising from genetic and intrauterine effects, that manifest with a few common features and many atypical features.
That's not all that interesting, so I'll go further. I also think that what's common in autism is the brain's frantic efforts to adopt to being broken. So one or many things is/are going "wrong" (quotes are important) in brain development, but there are common compensatory mechanisms that still work. The developing brain is breaking and trying to repair itself -- all at the same time. Somethings get repaired well, some don't. Sometimes the result works -- but it works differently.
Temple Grandin's mind works differently. Grandin is a famous interlocutor for autistic persons. She has several books and essays out, including this one: My Mind is a Web Browser: How People with Autism Think. Grandin has since recognized that she's really describing how she thinks, and that not all autistic persons think the same way [1]. The point, however, is that she has an "alien" way to thinking. It doesn't work all that well most of the time, but it is well suited to certain types of problem solving. She is a visualization 'savant' [2], in a way that some autistic persons are numerical 'savants'. She has enough symbolic reasoning and language to be able to translate from her world of visualization to the more common world of language.
Variations in neurodevelopment resulting by "malfunction" and adaptation/healing, yielding diverse minds that function better in some environments, worse in others.
Remind you of anything?
Isn't that how natural selection works?
We think that humans haven't evolved much in the past few hundred thousand years because our bodies seem similar. We are creatures of the brain though. What if there's an adaptive advantage to a "flaky" neurodevelopmental process? Maybe there's a reason we have so many "malformed" brains. It's not only that brains are hard to make, but also that there's a species advantage to having diverse brains and minds being created - even if some individuals bear a heavy price for being maladapted to the common environment.
Perhaps if we truly understood the human mind, we would discover that we are much less alike than we think.
[1] Grandin is nothing if not definite, but she also changes her mind. It's an interesting trait, and very scientific in a way. Overgeneralizing from self to all is a classic autistic trait, and not uncommon in neurotypicals either.
[2] It would be interesting to see how well Grandin could talk to a dolphin, presumably they think in sonar.
Tuesday, May 30, 2006
War crimes at Hadithah: not unique, inevitable
This I too believed before I read Arkin. I suspect it's what wise military leaders also believe about the marine revenge killings that occurred at Haditha [emphases mine]...
The difference between then and now is that our standards are higher than they were 70 years ago (progress happens), the battle conditions for US troops are consistently worse (occupation and insurgency) and the stakes are far lower.
Time to withdraw, and I believe the US military decided that some time ago.
Early Warning by William M. Arkin - washingtonpost.comI am 100% certain that allied forces fighting in WW II committed many similar atrocities.
...The truth of the matter, I hear from military sources, and an explanation I suspect is completely true, is that what happened in Hadithah that day has happened more times than the Marines and the Pentagon would like to admit, and more times certainly than the American public would like to admit.
And that's the issue.
American volunteer soldiers are fighting a frightening and frustrating battle against a never depleting and highly motivated enemy. The enemy is not in uniform, chooses to fight on a civilian battlefield, intentionally using civilians as fodder and shields to manufacture enough blood and chaos to drive the conventional army from the country.
The fog of war in Iraq, and part of the inhumanity particularly of the current situation on the ground is that the enemy chooses to look like everyone else on the streets, thus eliminating the fundamental element of "distinction" between civilian and military that is so essential to fight any kind of a just and humane war.
We are left then with the U.S. military, the finest conventional military force on the planet, a force that does more to train and prepare and comply with the law of war than any other country, a force that is uniquely accountable not just to the American people but to the entire world.
I suspect in this impossible war there are hundreds of incidents of accidental and intentional killings of civilians that have gone by without an investigation of any sort.
This is not to say that I am excusing what happened in Hadithah in any way. Bu Hadithah happened as much because war never follows the predictable script, and war can never be fully controlled. No matter how grave the justification for war, no matter how grand the experiment, the unleashing of human beings to justifiably kill other human beings exposes an animal instinct so basic and horrifying that training and leadership and uniforms can only tentatively arbitrate.
When killing in war become murder, we can delude ourselves into thinking that a few bad apples have stepped out of the "uniform" code and need to be punished. Right now though, we should be honest with ourselves and admit the hopelessness of our endeavor and the impossible situation we have created for our soldiers.
The difference between then and now is that our standards are higher than they were 70 years ago (progress happens), the battle conditions for US troops are consistently worse (occupation and insurgency) and the stakes are far lower.
Time to withdraw, and I believe the US military decided that some time ago.
Monday, May 29, 2006
The Deborah Howell affair: can bloggers improve a lazy (or corrupt) journalist?
DeLong makes it clear that the Washington Post's ombudsman, Deborah Howell, was either corrupt or lazy when she parotted the GOP party line.
She was pilloried by blog, and got some nastymail. She ranted about the nasty mail -- I suspect she's distorting how nasty it was but that's not the interesting topic.
The interesting question is whether this kind of feedback loop has any hope of improving someone who's a fairly weak journalist. If it does, that's something new in journalism.
She was pilloried by blog, and got some nastymail. She ranted about the nasty mail -- I suspect she's distorting how nasty it was but that's not the interesting topic.
The interesting question is whether this kind of feedback loop has any hope of improving someone who's a fairly weak journalist. If it does, that's something new in journalism.
Sunday, May 28, 2006
Establishing identity: Bloomberg's DNA database
NYC Mayor Bloomberg wants biometric ID methods for all:
In any case, he's right that we will do biometric identifiers one day -- whether iris scans or thumbprints or DNA fingerprints. Our failure to deal now with identity theft (by, for example, making banks liable for financial losses) will eventually make Americans happy to accept an identity management solution they might otherwise have refused. Funny how that works.
In any case Americans would gladly trade their privacy for convenience -- really, Americans are not very private people. The convenience/identity theft issues are a double whammy for biometric identification.
Oh, yeah, and "security" and immigration too. Make that a quadruple whammy, even though Schneier makes a good case that the security benefits are marginal or negative. (When identity is trusted you can do far nastier things once you breach the system borders than when it's not protected.)
Eventually we will also do a full DNA registry, which will be handy for identifying children likely to sin; including identifying future secular humanists. and finding evildoers and rebels through their kin. Might as well sign up now. I'll be registering for the 'authenticated flyer program' myself...
PS. I was going to write something caustic about the NRA's belief that owning weapons was some protection against state tyranny, but then I realized they don't talk about that any more. They only talk about using guns against fellow citizens -- not the state. I guess they feel the state would be on their side ...
BREITBART.COM - NYC Mayor Advocates U.S. Worker DatabaseHe's wrong about the SSN; even if one were as wealthy as Bloomberg, and didn't need to work, it's difficult to live in the US without having at least a fake SSN. The SSN is used very widely now; in fact one advantage of a true national ID number is that it would make visible abuses that are now obscure.
... You don't have to work _ but if you want to work for a company you have to have a Social Security card,' he said. 'The difference is, in the day and age when everybody's got a PC on their desk with Photoshop that can replicate anything, it's become a joke.'
The mayor said DNA and fingerprint technology could be used to create a worker ID database that will 'uniquely identify the person' applying for a job, ensuring that cards are not illegally transferred or forged...
In any case, he's right that we will do biometric identifiers one day -- whether iris scans or thumbprints or DNA fingerprints. Our failure to deal now with identity theft (by, for example, making banks liable for financial losses) will eventually make Americans happy to accept an identity management solution they might otherwise have refused. Funny how that works.
In any case Americans would gladly trade their privacy for convenience -- really, Americans are not very private people. The convenience/identity theft issues are a double whammy for biometric identification.
Oh, yeah, and "security" and immigration too. Make that a quadruple whammy, even though Schneier makes a good case that the security benefits are marginal or negative. (When identity is trusted you can do far nastier things once you breach the system borders than when it's not protected.)
Eventually we will also do a full DNA registry, which will be handy for identifying children likely to sin; including identifying future secular humanists. and finding evildoers and rebels through their kin. Might as well sign up now. I'll be registering for the 'authenticated flyer program' myself...
PS. I was going to write something caustic about the NRA's belief that owning weapons was some protection against state tyranny, but then I realized they don't talk about that any more. They only talk about using guns against fellow citizens -- not the state. I guess they feel the state would be on their side ...
All alpha all the time - convicting the CEO
The clue, my sister-in-law says, is the salad bar at the Harvard Business School. A flock of CEO-wannabees contending for one optimal asparagus makes a rough scene. These are competitive people -- much tougher fighters than most of us. If they do make the alpha grade, riding on the dopamine infusion of power, they get much tougher.
Remember OJ Simpson? It's extremely likely that he visciously murdered two people (he lost the civil suit of course), and yet, despite strong evidence of his guilt, he never cracked. An alpha.
How many politicians, caught with both hands in the jar, stand their ground no matter what? Tough. How many senior mobsters fight for 30 years without tiring? Tough.
Victorious alphas fight to live and they live to fight. Bloody battle does not tire them, it engages them.
So it makes sense that if you're going to go after corporate criminals, you use the techniques developed for mobsters:
PS. Thanks to M for the "all alpha all the time" title!
Remember OJ Simpson? It's extremely likely that he visciously murdered two people (he lost the civil suit of course), and yet, despite strong evidence of his guilt, he never cracked. An alpha.
How many politicians, caught with both hands in the jar, stand their ground no matter what? Tough. How many senior mobsters fight for 30 years without tiring? Tough.
Victorious alphas fight to live and they live to fight. Bloody battle does not tire them, it engages them.
So it makes sense that if you're going to go after corporate criminals, you use the techniques developed for mobsters:
Tough Justice for Executives in Enron Era - New York TimesThat's harsh. Very harsh. I'd have cracked long before my wife was sent to jail. But if you're going up against someone who makes the average gang-banger look like a kindergarden kid, what choices are there?
... When the former chief financial officer of Enron, Andrew S. Fastow, balked at cutting a deal with the government, prosecutors started putting pressure on his wife, Lea. She eventually pleaded guilty to income tax evasion for not reporting tens of thousands of dollars in kickback checks from one of Mr. Fastow's off-the-books schemes. Ms. Fastow went to prison for a year.
PS. Thanks to M for the "all alpha all the time" title!
Saturday, May 27, 2006
Taking the brains out of our prey
As I'd noted earlier, it's hard to come up with an objective system of ethics that gives humans special privileges. One of those special privileges is that we're allowed to eat other animals, but we frown on them eating us. William Saletan point out that this becoming an increasingly unavoidable paradox:
It's wrong though. The solution, as many people have noted for several years, is to take the brains out of our prey. We could breed a chicken with purely autonomic nervous system, likewise for cattle, sheep, etc. (Ok, let's not take this to its obvious conclusion. I don't want to ruin my appetite.)
It's time to stop killing meat and start growing it. By William Saletan: "The case for eating meat is like the case for other traditions: It's natural, it's necessary, and there's nothing wrong with it. But sometimes, we're mistaken. We used to think we were the only creatures that could manipulate grammar, make sophisticated plans, or recognize names out of context. In the past month, we've discovered the same skills in birds and dolphins. In recent years, we've learned that crows fashion leaves and metal into tools. Pigeons deceive each other. Rats run mazes in their dreams. Dolphins teach their young to use sponges as protection. Chimps can pick locks. Parrots can work with numbers. Dogs can learn words from context. We thought animals weren't smart enough to deserve protection. It turns out we weren't smart enough to realize they do.I went vegetarian primarily for ethical reasons for several years, but the burden of getting food into some difficult children broke that. I do like to eat meat, no denying it.
It's wrong though. The solution, as many people have noted for several years, is to take the brains out of our prey. We could breed a chicken with purely autonomic nervous system, likewise for cattle, sheep, etc. (Ok, let's not take this to its obvious conclusion. I don't want to ruin my appetite.)
Thursday, May 25, 2006
Using pain to prevent secular humanism
Salon has a disturbing review on the use of pain to prevent the development of secular humanist or liberal tendencies. Various whips and stinging tools are used to hurt infants and children, per the teachings of Michael and Debi Pearl.
How bad an idea is this? Does it really prevent the development of humanist tendencies? We don't really know. What research there is suggests it's probably a bad idea, but the studies are very hard to do well. To get good answers we'd need to randomize children to being hurt physically vs. hurt psychically (time out); the study would enver pass ethics board tests.
In the absence of evidence speculation is indicated. All child raising and puppy training is mixture of positive and negative reinforcement. For some children a 2 minute time out is agony, perhaps some of those children would actually prefer a slap on the wrist. For one child a spanking would be emotionally devastating, for another it might provoke more anger, for another it might be accepted and remembered. I have 3 children and have had two dogs. They are and were all over the map in terms of self-regulation and response to negative (loss of privileges and time-outs for the humans, training collars and in-your-face-yelling for the dogs) and positive (sticker charts, dog treats) reinforcers.
Practically speaking, however, there's a real problem with using physical pain - especially on human children. The problem is the parent.
We have lots of evidence that it's extremely hard to hurt a child in a measured and dispassionate way. Most parents can't manage it -- it takes a lot of anger control. (Same problem with using it on adults of course, as we all ought to know by now.)
The chances that a parent will be very good at using physical pain, and that a given child will actually respond well to it, are pretty low. I'd guess less than 5% of parent-child dyads. (If 1/5 parent good at it and 1/5 child benefits, then success probability is 1/5*1/5 = 1/25 = 4% -- so it's a bad idea 96% of the time).
On the other hand, the timeout by its nature gives both parent and child time to think. As do deferred privileges, etc. Inflicting physical pain is not a good approach, even though most children will survive it. Psychic pain, as in the time-out and the hostage light saber, is safer.
It won't prevent secular humanism anyway. Kids do things like that.
How bad an idea is this? Does it really prevent the development of humanist tendencies? We don't really know. What research there is suggests it's probably a bad idea, but the studies are very hard to do well. To get good answers we'd need to randomize children to being hurt physically vs. hurt psychically (time out); the study would enver pass ethics board tests.
In the absence of evidence speculation is indicated. All child raising and puppy training is mixture of positive and negative reinforcement. For some children a 2 minute time out is agony, perhaps some of those children would actually prefer a slap on the wrist. For one child a spanking would be emotionally devastating, for another it might provoke more anger, for another it might be accepted and remembered. I have 3 children and have had two dogs. They are and were all over the map in terms of self-regulation and response to negative (loss of privileges and time-outs for the humans, training collars and in-your-face-yelling for the dogs) and positive (sticker charts, dog treats) reinforcers.
Practically speaking, however, there's a real problem with using physical pain - especially on human children. The problem is the parent.
We have lots of evidence that it's extremely hard to hurt a child in a measured and dispassionate way. Most parents can't manage it -- it takes a lot of anger control. (Same problem with using it on adults of course, as we all ought to know by now.)
The chances that a parent will be very good at using physical pain, and that a given child will actually respond well to it, are pretty low. I'd guess less than 5% of parent-child dyads. (If 1/5 parent good at it and 1/5 child benefits, then success probability is 1/5*1/5 = 1/25 = 4% -- so it's a bad idea 96% of the time).
On the other hand, the timeout by its nature gives both parent and child time to think. As do deferred privileges, etc. Inflicting physical pain is not a good approach, even though most children will survive it. Psychic pain, as in the time-out and the hostage light saber, is safer.
It won't prevent secular humanism anyway. Kids do things like that.
The Harvard Business Review and Home Depot
The Harvard Business Review recently published a worshipful profile of Robert Nardelli and his brilliant work at refactoring Home Depot. Now the New York Times has a slightly different story:
With Links to Board, Chief Saw His Pay Soar - New York TimesI was impressed with HBR when I started reading it, but after a year I've seen a common pattern. A few good articles amidst a pile of Pravda style ego inflating propaganda. I won't be renewing.
... The discussion inevitably turns to the changes at Home Depot under its chief executive, Robert L. Nardelli. A growing source of resentment among some is Mr. Nardelli's pay package. The Home Depot board has awarded him $245 million in his five years there. Yet during that time, the company's stock has slid 12 percent while shares of its archrival, Lowe's, have climbed 173 percent.Why would a company award a chief executive that much money at a time when the company's shareholders are arguably faring far less well? Some of the former Home Depot managers think they know the reason, and compensation experts and shareholder advocates agree: the clubbiness of the six-member committee of the company's board that recommends Mr. Nardelli's pay. Two of those members have ties to Mr. Nardelli's former employer, General Electric. One used Mr. Nardelli's lawyer in negotiating his own salary. And three either sat on other boards with Home Depot's influential lead director, Kenneth G. Langone, or were former executives at companies with significant business relationships with Mr. Langone.
The marines learn the lessons of Abu Ghraib
In the face of war crimes that cannot be denied, the marines are now making the right moves:
Top Marine Visits Iraq as Probe of Deaths WidensWould the marines have pursued this if not for the TIME magazine article? I don't know, but they seem to be learning the lessons of Abu Ghraib. Instead of denial, they are preparing their response.
The commandant of the Marine Corps flew to Iraq to address his troops yesterday, and members of the Senate Armed Services Committee were briefed on allegations that Marines had purposely killed as many as two dozen Iraqi civilians in November...
Modern HIV is 75 years old
Chimps seem to do fine carrying SIV, so presumably they've been infected for millenia - or longer. It now appears human infection is about 75 years old:
I was in medical school when HTLV-III was identified, I grew up in the pre-AIDS era. Things were different then.
BBC NEWS | Health | HIV origin 'found in wild chimps'Humans may have contracted SIV before, but it never made the transition into an epidemic -- the victims would have died without passing on the disease. In 1930 it began the long ascent to its current pandemic status.
The origin of HIV has been found in wild chimpanzees living in southern Cameroon, researchers report.
A virus called SIVcpz (Simian Immunodeficiency Virus from chimps) was thought to be the source, but had only been found in a few captive animals.
Now, an international team of scientists has identified a natural reservoir of SIVcpz in animals living in the wild.
It is thought that people hunting chimpanzees first contracted the virus - and that cases were first seen in Kinshasa, in the Democratic Republic of Congo - the nearest urban area - in 1930.
I was in medical school when HTLV-III was identified, I grew up in the pre-AIDS era. Things were different then.
The return of estrogen?
Some neuroscientists believe the female brain does badly off estrogen, and moves from better-than-male to worse-off following menopause.
Controversial? A bit.
So the idea persists is that estrogen-like drugs may have a role in Alzheimer's prophylaxis in women.
I thought this idea bit the dust two years ago, but apparently it's still around. Undoubtedly pharmas want to split off the alleged neurprotective effects of estrogen from its effects on breast tissue.
Controversial? A bit.
So the idea persists is that estrogen-like drugs may have a role in Alzheimer's prophylaxis in women.
I thought this idea bit the dust two years ago, but apparently it's still around. Undoubtedly pharmas want to split off the alleged neurprotective effects of estrogen from its effects on breast tissue.
How to dismantle a democracy
Intelligence Czar Can Waive SEC Rules
The Bushies are writing the 21st century book on how to dismantle a democracy.
The Bushies are writing the 21st century book on how to dismantle a democracy.
Why are we so different from one another?
It is the casual question at the end of this story that caught my attention (emphases mine). The story itself is quite remarkable. Once upon a time I was taught "one gene, one protein". That turned out to be untrue, though a useful initial simplification. The relation between genes and proteins (the builders) is many to many, not many to one or one to one. Later I was taught that nuclear DNA was the fundamental basis of heredity. Then we learned that mitochondria had their own DNA and that prions could carry encoded protein altering directions without DNA. Until today most of us thought that animal heredity worked through DNA and histone imprinting alone. Now that may not be quite true either...
Biology reminds me quite a bit of physics. When I was a child we had protons, neutrons, photons and electrons (at least in popular science books for children). Shortly thereafter there were bazillions of particles. A simple story became rather complex. So goes biology ...
BBC NEWS | Science/Nature | Spotty mice flout genetics laws [jf, aka: RNA directed paramutation in mice]Did you know that biologists are quite puzzled about why we humans, who seem so similar at the DNA level, are so different in practice? I'd thought that research in the control of gene expression suggested that tiny changes in DNA control could produce large changes in protein expression. It appears the question is not so settled.
... Researchers found that mice can pass on traits to their offspring even if the gene behind those traits is absent.
The scientists suggest RNA, a chemical cousin of DNA, passes on the characteristic - in this experiment, a spotty tail - to later generations...
... They found the mutant Kit gene produces large amounts of messenger RNA molecules (a type of RNA which acts as a template for the creation of proteins) which accumulate in the sperm of these mice.
The scientists believe the RNA molecules pass from the sperm into the egg, and they "silence" the Kit gene activity in the offspring - even those who do not inherit a copy of the mutant gene. Silencing the activity in this gene leads to a spotted tail...
...The phenomenon whereby the characteristic of a gene is "remembered" and seen in later generations, even if that particular version of the gene is no longer present, is called paramutation.
It has previously been identified in plants, but this is the first time it has been shown in animals together with a proposed mechanism - if the explanation is confirmed in future experiments...
Could transfer of RNA in sperm explain other so-called epigenetic phenomena as well?
... "A particularly intriguing possibility," he writes, "is that such RNAs regulate other non-genetic modes of inheritance, such as metabolism or behavioural imprinting."...
... "This brings valuable information about modification of our genome," said Minoo Rassoulzadegan, "and perhaps this research may eventually help us to understand why we are all so different from each other."
Biology reminds me quite a bit of physics. When I was a child we had protons, neutrons, photons and electrons (at least in popular science books for children). Shortly thereafter there were bazillions of particles. A simple story became rather complex. So goes biology ...
Subscribe to:
Posts (Atom)