
Your DNA may carry a ‘memory’ of your living conditions in childhood - pg
http://scienceblog.com/48584/your-dna-may-carry-a-%E2%80%98memory%E2%80%99-of-your-living-conditions-in-childhood/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+scienceblogrssfeed+%28ScienceBlog.com%29
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ihartley
I'm currently involved in research regarding DNA methylation in mice.
Epigenetic modification is really interesting and still not very well
understood insofar as how the response occurs. These methylation changes may
also occur as a response to other environmental stresses later in life as well
as childhood, and other epigenetic modifications may be passed to offspring.
We should see some very interesting discoveries that change our current ideas
of heritability and response to environmental stimuli in the next few years as
we're able to better detect the epigenetic factors in a cost effective manner.

~~~
Peroni
The recent advancements in DNA research absolutely fascinate me. What really
intrigues me is how easy/difficult it is for our environment and current
mentality affect our DNA.

~~~
gldalmaso
I have always thought that the random-mutation factor in Darwin's evolutionary
theory was a rather poor explanation to the highly specialized organisms we
see today. In that specific account I've, personally, always favored
Lamarquism as the simplest, most plausible theory.

Of course such an opinion might be considered 'heretic' among the scientific
society, which I found to be way too dogmatic on most aspects.

~~~
drzaiusapelord
>Of course such an opinion might be considered 'heretic' >which I found to be
way too dogmatic on most aspects.

Go ahead and design some falsifiable and testable experiments to prove this.
You can whine about dogmatism or you can challenge it. I suspect like more
Lamarckian ideas its quickly refuted, but you are welcome to try. That's how
science works.

As far as I, any many others, can tell, random mutation and natural selection
works really, really well, but would love to be proved wrong. Please note
"proven" isn't flowerly speech about how some ideas "feel" righter than
others.

Sorry, I didn't mean to sound like a dismissive asshole, but epigenetics is
still a young science. We can't even tell if this stuff in inheritable or if
it even makes any difference if it was. Epigenetic inheritance even if real
doesn't change genes it just changes expression. Its really not like Lamarck
at all (if you are fat and like rap music, you will have fat children who like
rap music because magic, that's why!).

~~~
drzaiusapelord
>In fact, from a quick glance in history we see science prove itself wrong
over and over again,

That's a feature, not a bug. Think something is wrong? Prove it. Then it
becomes the status quo. Then that gets either refined or dismissed by a better
theory. You may say this process is evolutionary...(oh, I love puns).

Are there egos and politics involved? Yes, just like in any human endeavor.

------
brudgers
This != evidence for Lamarkian Genetics

What would need to be shown in order to support Lamarkianism is that the
methylation patterns are passed on to offspring (and showing that the
methylation patterns in childhood were different from those at birth, would
probably be helpful as well).

It is fallacious to extrapolate from patterns of reproduction at the cellular
level of amino acids to reproduction patterns at the organism level of sperm
and egg. It is akin to applying quantum mechanics to billiard balls.

What the study does show is that there are long term effects of childhood
living conditions which manifest themselves at the celluar level. Given that
we are readily able to observe some effects of childhood living conditions at
the macro level of the human organism (e.g. physiological manifestations of
diet or altitude), finding their biochemical mode of expression should not be
entirely unexpected.

~~~
Produce
I would argue that it (sort of) is because most people tend to stay at the
socioeconomic level they were raised in. In other words, the mechanism for
carrying this forward is not in the DNA but the culture.

~~~
brudgers
Wouldn't that be more a case of memetics rather than genetics?

[<http://en.wikipedia.org/wiki/Memetics>]

~~~
Produce
Yes, you're completely right about that.

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chrisbennet
There was a facinating Nova show on epigenetics back in 2007 called "The Ghost
in Your Genes" about the discovery that epigenetics could have
intergenerational effects. I couldn't find a link to the video just to a
transcript: <http://www.pbs.org/wgbh/nova/transcripts/3413_genes.html>

~~~
gmkoliver
I saw this for a class recently, here's the link (part 1 of 5):

[http://www.youtube.com/watch?v=toRIkRa1fYU&list=WL7AE0E3...](http://www.youtube.com/watch?v=toRIkRa1fYU&list=WL7AE0E3F91F538F8C&index=1)

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Alex3917
For what it's worth, epigenetics and methylation is one of the reasons why
cannabinoids have shown anti-cancer properties:

[http://www.drugs.com/clinical_trials/turned-off-
cannabinoid-...](http://www.drugs.com/clinical_trials/turned-off-cannabinoid-
receptor-turns-colorectal-tumor-growth-5233.html)

Essentially in some cancers the cells lose their ability to uptake
cannabinoids because those receptors get methylated, and so by unmethylating
them (and adding extra cannabinoids) you can attack the cancer.

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david927
You can't pass on these DNA methylation changes, right? But does this bring
Lamarckism back into the realm of conceivable?

~~~
jforman
Recent studies show there may actually be some limited transmission of
epigenetic information:

[http://learn.genetics.utah.edu/content/epigenetics/inheritan...](http://learn.genetics.utah.edu/content/epigenetics/inheritance/)

Our understanding is still very limited, though. And yes, it is kind of ironic
that Lamarck is getting a jab in after all this time :)

~~~
gldalmaso
I always thought that the scientific community accepted Darwin's random-
mutation factor way too easily and without challenge. It never seemed very
credible to me. The more I watched wild life documentaries the more Larmackism
grew on me.

~~~
jforman
I can't tell if you're joking or not, but just to be clear: traditional
genetics' utility for explaining natural variation among individuals
represents an enormous increase in scientific understanding, and is supported
by tens of thousands of scientific papers and countless benefits to society.

It's somewhat absurd to compare the credibility of genetics as a field to what
is still almost entirely conjecture.

~~~
gldalmaso
I never said genetics as a whole is not credible, it's the random part that I
think is off, just to clarify.

From our brief history of mankind, I don't think there's enough information
and hard fact to either prove or refute the random factor, as far as I know it
is just accepted. I could also be wrong since I'm not all that up to date in
this matter.

~~~
jforman
The mechanisms of traditional genetics, which include (at a simplified level)
random variation at the base-pair level, are extremely well understood.

The impact of this potential new mechanism of inheritance is unknown, but it
will only add to our current understanding of how things work. It will not
tear down our understanding.

------
leeHS
Based on how meiosis works, I can see how methylation could be passed down to
offspring. But these changes in methylation would have to occur within the
specialized cells which produce sperm and egg. If the methylation pattern
changes in your liver or heart cells, it doesn't matter since these somatic
cells don't get to pass this information on to offspring.

Females are born with all their eggs, so any changes in methylation that occur
to these eggs will persist into adulthood (I assume). But is it possible that
these eggs are somehow protected from this alteration? As for sperm, these are
produced within the testes following puberty, and are generated continuously.
Therefore, in order to pass down altered methylation, the original gamete
cells responsible for generating sperm would have to be altered. But if you
wanted to do this successfully, you'd have to make sure to alter ALL the
gamete cells. Otherwise you're gambling as to which sperm cell hits the pay
load. Again, I'm curious if these cells are more or less prone to altered
methylation.

I find this whole concept fascinating! Imagine...your dad gets bullied as a
kid, results in altered methylation pattern, and this gets passed to you! Wow.

~~~
leeHS
What I also find fascinating is the number of individuals with this sort of
background reading/commenting on HN. I think it's great! Are many of you into
Bioinformatics?

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maxklein
One thing I have observed, particularly with Africans, is that if they grow up
in Europe or if they grow up in Africa, there is a clear difference in the way
they look when they are older, no matter their socio-economic status at that
point.

~~~
athesyn
I think you are confusing African ethnicities (since only using the word
Africans is quite superfluous anyway).

Africa is the most diverse continent in terms of phenotype and genetics. For
example: a West African, an Ethiopian and a San person have very little in
common, physically speaking. It is a bit like saying African Americans are
'African' while most have admixtures with non-Africans.

Studies showed that Ethiopians (toward 50-55%) and Kushites (towards 35% for
Bejas) have an important western asian input so they tend to look like
transitional people.

~~~
maxklein
I'm not confusing African ethnicities. I mean people from the same extended
family, living in london.

Take a look at this link: [http://www.traedays.com/blog/2006/06/are-you-
thinking-what-i...](http://www.traedays.com/blog/2006/06/are-you-thinking-
what-im-thinking-character-and-speech/)

~~~
athesyn
All of them look very Nigerian to my eyes. Maybe if that blogger looked past
his own cultural bias, he would notice there is variation amongst themselves.

~~~
tokenadult
It's not clear without further scientifically designed testing whether there
is more "cultural bias" in grouping people by saying "All of them look very
Nigerian to my eyes" or by saying that it is easy to see which of the varied
individuals grow up in the West and which grew up in Nigeria. (It's an
empirical question, first of all, whether observer identifications of that
kind can be verified by controlled experiments with unfamiliar individuals in
either case.) There are definitely different cultural biases among human
beings about whether environment of development matters most or ancestral
lineage group matters most in making distinct human individuals more or less
alike for the social purpose of grouping them by some commonality. One
refreshingly interesting fact I learned from the book The History of White
People by Nell Irvin Painter

[http://www.amazon.com/History-White-People-Irvin-
Painter/dp/...](http://www.amazon.com/History-White-People-Irvin-
Painter/dp/0393049345)

is that the ancient Greek authors were overwhelmingly of the opinion that what
made different people groups different from one another was different living
environments (climate and topography), with the Greeks of course thinking that
their living environment tended to produce superior people.

------
willpearse
I too work in biology, and while this is interesting, that there are
differences between people is not that surprising, and attempting to link
socio-economic conditions to such widely different methylation patterns when
you've got a sample size of 40 isn't very convincing. That said, nice work!

------
th0ma5
DNA is expressed in RNA synthesizing proteins that in turn feedback to RNA,
which feeds back to DNA, right? And this happens over multiple generations,
and sometimes in a single person, depending on what aspects of which
combination of the system we're talking about?

------
6ren
<http://en.wikipedia.org/wiki/DNA_methylation> seems to be a kind of cell
parameterization, amongst other things.

------
jwallaceparker
I'd be curious to get a DNA reading to see if it matched my real world
conditions.

------
tintin
Could this explain the dreams and desires of the formal owner after a
transplant?

~~~
tintin
Maybe someone could explain the downvotes? This is a serious question. There
have been stories about for instance heart transplantations where the new
owner experiences dreams and desires of the first owner although the persons
never met. These stories were always marked as 'not possible' but now it seems
a bit more 'plausible'.

~~~
omarchowdhury
This research is not stating that memory is stored in DNA. The headline uses
the word 'memory' as in 'influence'. The living conditions of a particular in
childhood influences their DNA post-childhood.

