Is an 'Evil' gene nonsense?
If lightning strikes a tornado... A fast answer
I
read that a Swedish scientist may have discovered the 'Evil'
gene that causes Man to kill, murder, start wars etc. Is this 'discovery'
another one of those theories classed as nonsense? John, England
This is a Florida State mug shot of serial killer Ted Bundy, who was tried
and convicted of killing two women in Florida. Bundy eventually
confessed to killing 37 young women. "I'm the most cold-blooded sonofabitch you'll ever meet. I just liked to kill, I wanted to kill,"
said Bundy.
'Evil' is too complicated a concept for a scientific inquiry. Let's
limit the discussion to aggression or violence.
Perhaps you're referring to an article that appeared in New Scientist
about breeding fruit flies for aggression. Two scientists (Ralph
Greenspan, senior fellow, and
Herman Dierick, research fellow, of the Neurosciences Institute in San
Diego) managed, after 21 generations, to produce super fighters that could
outfight any fruit fly around. The super 'sluggers' started more fights,
kept fighting longer and fought more viciously than their sparring partners (the
controls). They didn't just chase and hit, but wrestled and flipped the
other guys.
Greenspan and Dierick examined the flies' brains for possible causes of the
intense aggression. They found higher levels of an enzyme (CYP6a20).
Moreover, a
single gene produces this enzyme. They concluded a single gene caused the
increased aggressive behavior.
Does that imply a similar, single gene in humans causes our violence? Extremely unlikely.
"There is no single gene capable of producing criminal behavior per se,"
writes Adrian Raine
(Richard Perry University Professor in the departments of criminology,
psychiatry, and psychology at the University of Pennsylvania, who studies the criminal brain) in the
Psychopathology of Crime.
Could several genes act together, coupled with the 'right'
sort of an environment, drive some people to pathological violence? Raine
believes this to be the case — a genetic predisposition for violence.
In fact, researchers studied a large number of males from birth to
adulthood, and found such a genetic predisposition, emails Greenspan. A
couple of studies showed a genetic variant in a particular enzyme (monoamine oxidase-A aka MAOA) had a significant impact on whether or not the man developed antisocial problems. A male with low levels of the enzyme was
more likely to veer toward adult violence, if someone had severely abused
him as a child. High levels gave him protection against ending up in
trouble even if he had been mistreated earlier.
"A very interesting and emblematic example of the interactions between
genetics and environment," Greenspan says.
Further Reading:
Single gene turns fruit flies into fighters, NewScientist.com, August, 2006
Psychopathology Of Crime: CRIMINAL BEHAVIOR AS A CLINICAL DISORDER, Academic
Press, 1993
Scientists Discover a Genetic Basis (the absence of a single gene) for
Aggressive Behavior in Male Mice, John Hopkins University, 1995
Caspi A, McClay J, Moffitt TE, Mill J, Martin J, Craig IW, Taylor A, Poulton R.
Role of genotype in the cycle of violence in maltreated children.
Science. 2002 Aug 2;297(5582):851-4.
Kim-Cohen J, Caspi A, Taylor A, Williams B, Newcombe R, Craig IW, Moffitt TE.
MAOA,
maltreatment, and gene-environment interaction predicting children's mental
health: new evidence and a meta-analysis.
Mol Psychiatry. 2006 Oct;11(10):903-13.
Readers' Answers
- A couple of years ago, researchers at Duke University (Terrie
Moffitt and Avshalom Caspi), did, indeed, discover a gene for recidivist
criminal behavior. I don't know if this is the same finding the
writer was referring to, but it certainly is relevant. If I remember
correctly, only men carry it (big surprise!) - about 30% of them. It only
seems to be activated if it is coupled with a childhood of abuse (nature AND
nurture both required).
Marlene Sanford, Greensboro, North Carolina
- [Marlene emailed neuroscientist Terrie Moffitt,
professor at Duke University, about the study.
Moffitt responds here. AH]. You are right that the gene, which is called MAOA, was not connected with crime and violence unless the individual had a
history of maltreatment as a child. So, rather than a gene for violence,
instead this seemed to be a gene that influenced how vulnerable or resilient
children are to stress. MAOA functions in the brain to mop up excess chemical
messengers between brain cells. Teams in seven countries have tested the original 2003 finding by now, and overall it is still holding up. It's small,
but it seems to be there.
By the way, we tested this in boys only, because MAOA is on the X
chromosome. Boys only have 1 X, so it is easy to test whether a boy has the
vulnerable of resilient genotype. Girls have 2 X's, so they are (wouldn't you
know it) more complicated. So far, it is not known how to tell which X in a
given girl is the active X, so we could not test if MAOA predicts women's
aggression among girls who have been abused as kids. It might, but we cannot
test for that.
Terrie Moffitt, Durham, North Carolina
- To answer your "Evil Gene" question: No it isn't true, as "evil" is not
scientifically quantifiable, in particular, the extremely complex behaviors
given as examples, "murder", "start war", cannot be defined scientifically.
Justice systems, which have a much lower standard of evidence, already have a
difficult time with such questions.
Vardi Ilan, Montreal, Canada
- It is remarkable how genes are credited with giving specific capabilities
and effects on an organism, without really asking "why might it do that?"
A researcher, who was trying to develop a salmon suitable for farming in
waters that may periodically freeze, located the "antifreeze" gene in flounder
and spliced it into salmon. Reportedly the antifreeze part did not work, but
the resulting fish grew much faster than the normal salmon. Gene isolation is
not as easy as it has been described in reports, because genes create
proteins, not individual features. Isolating a disease to a gene is more
direct, since the protein the gene creates might represent a symptom.
A lot of the task of determining which of the billions of genes has what
effect is achieved mathematically: from sample populations, try to correlate
the presence of a characteristic with the presence of a particular gene
sequence in the genome. The bigger the population sample and the more
precisely defined the characteristic, the better your chance of isolating
something – but not necessarily everything.
Nowhere in the above is there an attempt to define what purpose the gene
might be serving in the organism, so the characteristic isolated may only be a
byproduct of a much more wide-ranging set of effects. Furthermore, it may only
work in conjunction with other genes, or there may need to be an environmental
trigger that actuates the gene’s response.
So somebody claims to have isolated an "Evil" gene, right? Are we to
believe that all "antisocial" activity (if you can define that suitably
clearly) is strictly the effect created by one (or more) genes? Oddly enough,
a lot of triggers for murders, wars and other evils have been traced in
people’s histories to have environmental triggers. We also know that certain
situations (like a mob scene) can have a person perpetrate an act that they
would never have considered normally.
Chances are the personality traits associated with the "evil" being sought
are aggressiveness and lack of empathy. They’re also associated with the
entrepreneurial spirit and the risk-taker – when we consider the positive side
of the characteristics. In short, even if there is a gene associated with
"Evil" it is not going to be working alone. The values induced by upbringing
and social position are going to influence how the behavior is expressed.
If individuals partake in "Evil" with no particular gain or benefit
expected, we consider them mentally ill. To date, there is limited evidence
that there is a major component of this being passed from one generation to
the next in families of "Evil" people, which would happen with a gene.
Therefore, it’s really more likely that the gene being discussed is, at best,
one of a whole orchestra of potential sources of evil, and it’s when multiple
instruments all strike the right "chord" that a notably Evil note sounds.
Bob Maxwell, Alton, Ontario , Canada
If lightning strikes a tornado...
What would happen if a lightning bolt hits a tornado?
Nick, Lewisville, USA
A tornado touching down on May 3, 1999 in central Oklahoma. Photo courtesy
of NOAA.
A tornado would scarcely notice lightning discharging through it.
"The power surge is neither strong enough nor long
enough to disrupt the tornado vortex," emails lead forecaster
Roger Edwards of
NOAA's Storm Prediction Center.
The odds of a lightning bolt hitting a tornado are extremely small. "I have watched
a hundred tornadoes in person and videos of hundreds more; I haven't seen any
examples yet." Lightning does strike sometimes in front of or behind the
tornado, which gives the illusion of actually hitting it.
Tornado winds, however, can change where lightning might strike,
says Edwards. As a negative electric charge builds in the cloud and a positive charge builds in the ground, an invisible charge
channel "wiggles" down from the cloud, following the path of least
resistance to ground. But intense buffeting winds can deform the
zigzagging channel, and cause other branches to be better paths. Then the
electrical charges choose the better path to neutralize the charge differential.
Thus, a tornado's winds can affect lightning, but lightning can't disrupt a
tornado's vortex.
Further Reading
The online
tornado FAQ, by Roger Edwards, NOAA
A SEVERE WEATHER PRIMER: Questions and Answers about TORNADOES, National
Severe Storms Laboratory
Langmuir Lab Researchers' Volcanic Lightning Study In Science, New Mexico
Institute of Mining and Technology
What causes lightning? WonderQuest
(Answered April 14, 2008)
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