
Heredity Beyond the Gene - dnetesn
http://nautil.us/issue/58/self/heredity-beyond-the-gene
======
learnstats2
Contrary to some other comments, heredity by definition excludes culture.

Heredity can be measured via twin studies - if twins are adopted into two
different families or cultures: what commonalities can we still find, beyond
random variability. The goal is to take culture out of the consideration and
look at the biology. (You may argue how successful this can be, but it is the
goal, and it is what is meant by ‘heredity’)

It’s reasonable to expect/have learned that all heredity must come through
genes - which the headline illustrates - but we are starting to explore other
mechanisms for heredity.

The article makes no comment on cultural transmission, which is entirely an
independent concept.

~~~
thraway180306
Heredity has no definition other than mathematical tools used to measure it.
Do you say statistics has the power to exclude environment's influence just
because you made up some definition on the label of the measured variable?

Specifically about the twin studies this has been heavily criticized from
their outset. Already Flynn (of the famous Flynn effect of IQ increase over
time) put out the requirements for proper control of such studies in his 1980
book. Nevertheless in 30 years of conducting new ones it appears none improved
the methodology to control more carefully for environment and for culture.
Just one facet of their invalidity: adoptive families have been found to be
exceedingly intelligent with IQ over 120 on average, which is obviously
different than general average (Stoolmiller in Psychol. Bull. 125:392-409).

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calibas
I assume most people were taught the same things I was, namely that Lamarckism
is ridiculous nonsense, and now we're finding it has elements of truth.

~~~
09bjb
I like the attitude, that we can't throw anything out completely if we're to
be open to new learning...but let's categorize these effects as "epigenetics"
broadly and leave Lamarckism at rest :)

~~~
trendia
But even epigenetics does not cover all of the ways that derived traits can be
passed. For instance, prenatal testosterone levels affect the baby [0], yet
those same levels may be affected by the mother's environment. Hence the
environment may have effect on lifespring through means other than just
epigenetics.

[0] [http://www.abc.net.au/news/science/2015-09-23/masculine-
face...](http://www.abc.net.au/news/science/2015-09-23/masculine-face-linked-
to-testosterone-levels-in-womb/6795422)

~~~
toasterlovin
Prenatal testosterone can alter the baby's phenotype, but can it alter the
baby's genotype?

Something has to alter the baby's genotype (more specifically, the genes in
germ line cells, which are the only cells whose genetic material gets passed
on to offspring) in order to count as a method of heritability. Otherwise
prenatal testosterone is the same as any other thing in the environment which
can alter an organism's phenotype.

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stcredzero
There's another kind of heredity which it's very important to discuss, with
regards to opposing certain problematic ideologies. (Both far left and far
right.)

For human beings, culture, as a powerful multiplier of intelligence, is far
more important than genes. Immigrant groups to the US, like Italians and
Poles, increased their average IQ scores by about a whole standard deviation
in about 2 generations in the early 20th century. Even hot-button topics, like
the IQ scores of Black people in the US have data which suggest that it is
culture which is both a source of great inertia/difficulty and a source of
great hope. On the side of hope, one study found that the Black children of US
service-people in Germany were the same as other children growing up in
Germany. Likewise, evidence for cultural factors in the success of people in
various fields is very strong. For example, Jewish immigrant communities have
often dominated local tailoring industries in cities across thousands of years
of history and several continents. However, it would be laughable to suggest
the existence of a tailoring gene.

Information of the kind above has been suppressed by the Far Left in the West.
It has also been taken up in a dishonestly distorted form by the worst fringes
of the Alt-Right. However, the complete story demolishes both Far Left and
Alt-Right ideological messages. In the power of culture, there is hope for the
future. If the potato famine Irish could lift themselves to their current
place in 21st century society, out of utter unemployable status, poverty lower
than that of the contemporaneous American slave, and the sewage-smelling crime
and terrorism-ridden slums of New York and London, there is nothing that
cultural transmission can't do.

[http://a.co/6K2o7XS](http://a.co/6K2o7XS)

[https://www.youtube.com/watch?v=WHr9GRgRw_M](https://www.youtube.com/watch?v=WHr9GRgRw_M)

[https://www.youtube.com/watch?v=3w0X71d9Z08](https://www.youtube.com/watch?v=3w0X71d9Z08)

(Also herein is a cautionary tale. History shows many, many examples of
migrant groups who find themselves lagging behind. They are often kept in
cultural isolation away from the mainstream of their local society, often, by
their own elite, which uses this to maintain their status as group leaders.
Culture is powerful, but its power can be harnessed to do great harm as well.)

~~~
toasterlovin
I think it's always handy to keep in mind that human culture is a result of
genetics.

~~~
stcredzero
Both of those factors interact. However, it would be ridiculous and extreme to
say that human culture is entirely genetically inherited and transmitted.
Given the data, I'd say that the lion's share of culture is learned. When it
comes to biologically based systems, the lesson of Darwinian vs. Lamarckian
evolution in 2018, is that, "It's complicated."

~~~
toasterlovin
> I'd say that the lion's share of culture is learned.

I would say that the majority of what makes a given culture unique and
different from other cultures is learned. But the elements of culture that are
shared between cultures are probably based in genetics.

Also, regarding Darwinian vs. Lamarckian evolution: my reading is that
epigenetics is mainly comprised of some interesting phenomena that, when taken
together, don't really account for that much of the genetic variety that we
see in humans and, thus, are more of a fleshing out, rather than a revolution,
of our understanding of genetics.

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triviatise
lamarckianism is not nonsense at all. It has been known in microrganisms for
at least 30 years and is one of the foundations of molecular biology research.

Plasmids are genetic structures that can be acquired by a bacteria and then
passed on to descendants or through the environment to peer organisms.
Antibiotic resistance is one of the most common traits passed this way.

~~~
tsax
Greg Cochran, an expert geneticist who wrote 'The 10,000 Year Explosion' has a
different view.

1)
[https://www.youtube.com/watch?v=w3310KWlDXg](https://www.youtube.com/watch?v=w3310KWlDXg)
(especially the Q&A which is dominated by epigenetics).

2) This explains it in text ->
[https://westhunt.wordpress.com/2012/10/26/epigenetics/](https://westhunt.wordpress.com/2012/10/26/epigenetics/)

~~~
cadlin
Greg Cochran isn't an expert geneticist. He's a consultant with a PhD in
physics who was an anthropology adjunct for ten years.

He doesn't have any training as a geneticist or in biological research.

It's all in his LinkedIn: [https://www.linkedin.com/in/gregory-
cochran-48b51b79/](https://www.linkedin.com/in/gregory-cochran-48b51b79/)

------
ozy
Since life or evolution is basically self-replication with variation in a
shared environment, any mechanism that can carry information forwards can and
probably will be used, or has been in the past. From that perspective, some
phenotype changes are trivially genotype changes. (Eg anything that changes
the egg-cell, will influence the life that grows from it.)

It is weird to expect only DNA to be used. The process is not that orderly.
The special thing about DNA (and a few other mechanisms), it is invariant to
phenotype changes. And that it will copy over information that has no direct
influences on self-replication. That is what enabled unlimited heredity.

~~~
AstralStorm
Not that weird in fact. For hereditary information too be properly passed on,
the mechanism must be relatively stable and somewhat controllable. The known
epigenetic mechanisms (e.g. methylation patterns) fit this bill.

Cell also has more than just a single set of DNA - it also inherits
mitochondria and maternal mitochondrial DNA.

Maternal phenotype is important only so far as it affects cell development
very early in life or has strong effect on epigenetic mechanisms. Those
mechanisms are indeed affected by conditions "in the womb".

As for paternal effects, sperm is an antigen and hormone too.

The article seems to be written to a person stuck in very old view of genome
and heritability. I'm pretty sure no accrual scientist in the field believes
the core thesis.

~~~
macawfish
A relative of mine has a recent PhD in pharmacy and wasn't familiar with this
way of thinking. (In our conversation, they also expressed a believe that race
is genetic). My hunch is that there are still a lot of old school professors
out there, firmly stuck in their neodarwinian ways, teaching students like my
relative outdated paradigms. It wasn't too long ago that this framework was
scientifically taboo, considered Lamarckian, even pseudoscience. And
scientists are horrified of being called "crack pots" or "pseudoscientific".

~~~
akatechis
Race is definitely genetic.

~~~
rflrob
In one particular sense, it is true that there are genetic elements of race
and that some genetic diseases are more prevalent among those of one race than
another. But once you start drilling down into what we mean by "race", it's
not at all a simple picture. For one thing, there are almost no markers that
are perfectly diagnostic for race—almost any particular polymorphism is found
in almost every race, though at different frequencies. Furthermore, some of
what naively you would consider a race (e.g. "Black" or "White") is composed
of multiple, genetically distinct populations that are no more closely related
to each other than to other populations not in that race.

So most serious geneticists have tended to move away from thinking of "race"
as closely linked to genetics—the complicated contours of both population
genetics and what we mean when we talk about race just don't fit together all
that well, and coupled with a history of unethical policies justified by
overly simplistic scientific knowledge in this field, it's best to be careful
about the terms we use.

~~~
corporateguy5
Dogs are to breeds as humans are to race.

~~~
frenchy
The morphological difference between dog breeds are clearly much larger than
human races. I suspect the genetic is larger as well, but I have no data to
support/deny that claim.

Also, what we think of as race typically has a lot to do with cutural & socio-
economic traits. Race isn't a clearly defined concept and might mean slightly
different things to different people.

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a_bonobo
There is a bit of very recent, new epigenetics controversy in this preprint:
[https://www.biorxiv.org/content/early/2017/09/20/170506](https://www.biorxiv.org/content/early/2017/09/20/170506)

>Frequent lack of repressive capacity of promoter DNA methylation identified
through genome-wide epigenomic manipulation

tl;dr: they engineered a protein which methylates regions of the genome in
human cells and checked how that affects gene transcription. In many cases
where they showed that the gene's regulatory region was methylated were still
transcribed, contrary to what many other studies are indicating.

>These findings suggest that promoter DNA methylation is not generally
sufficient for transcriptional inactivation, with implications for the
emerging field of epigenome engineering.

Perhaps methylation could be a footprint of something we don't know about yet.

------
yters
If Lamarkianisn is true, then is intelligent design true?

~~~
daemonk
How do those two things relate?

~~~
yters
Lamarkianism claims animals manipulate their own genome to achieve a purpose.
Intelligent design claims evolution exhibits purposeful change, which can be
scientifically detected. Darwinian evolution claims all purpose is illusive,
and merely a function of random variation and natural selection. Consequently,
if Lamarkianism is true, then so is intelligent design.

------
xr4ti
I don't see why this should be very surprising to people. It's not difficult
to think of heritable traits that have nothing to do with genetics such as:
social status, money/property, spoken language, etc. Biological phenomena
exist on molecular, cellular, organismal, population, and planetary scales.
The assumption that genetics would be the only mode of entanglement would seem
to be overly reductionist.

~~~
toasterlovin
Heritability has a different meaning from how you are using it. A trait is
heritable if a child displays the trait regardless of their environmental
milieu. So, language is not heritable because the language you speak depends
solely on the environment you grow up in; the child of English speakers will
speak Spanish if they are raised in an environment where only Spanish is
spoken. Height, on the other hand, is heritable, because, absent major
malnutrition, the child of tall parents will be tall regardless of the
environment they grow up in.

And regarding status and wealth: genetics probably play more of a factor in
these than you think.

~~~
xr4ti
Not sure I agree. Inheritance refers to flow of influence on properties from
parent to child. I think anything beyond that high level definition requires
additional qualifiers (e.g. genetic heritability). Inheritance is typically
not deterministic, even in the case of genetic heritability.

For example, the statement that tall parents will always have tall children is
incorrect, though there is a strong bias. I would be curious to see how the
probabilistic linkage between parent and child height compares to that for
language. My guess is that parent language has a stronger effect than 99.9% of
SNPs identified in GWAS.

If you really think about the difference between the two inheritance scenarios
you outlined, it's that one mechanism of influence occurs at a scale that
readily admits direct observation and perturbation while the other doesn't.

I don't think we (humans) know anywhere near enough about how genes compare
and interact with other factors to support an argument either for or against
your final statement.

~~~
toasterlovin
[https://en.wikipedia.org/wiki/Heritability](https://en.wikipedia.org/wiki/Heritability)

Heritability has a very specific meaning. The first sentence from that
article: "Heritability is a statistic used in the fields of breeding and
genetics that estimates the degree of variation in a phenotypic trait in a
population that is due to genetic variation between individuals in that
population."

The key part in that sentence is "due to genetic variation between individuals
in that population".

Yes, there is a very strong relationship between first spoken language of
parent and first spoken language of child. But there is no genetic element to
that relationship (Asian children adopted by American parents will speak
English, not the language of their parents), thus first spoken language is not
heritable.

> I don't think we (humans) know anywhere near enough about how genes compare
> and interact with other factors to support an argument either for or against
> your final statement.

There is a difference between knowing that an effect exists and knowing how an
effect works. We know, via twin studies, that IQ and height are highly
heritable (50-80% for IQ; 80% for height), even though we don't know all the
genes responsible or the way in which they contribute. Similarly,
wealth/financial status have been shown to be heritable. Siblings raised apart
will have levels of wealth that are more similar than random strangers.
Identical twins raised apart, even more so.

