Common (hilarious!) misunderstandings
The articles,
lectures, and these webpages of answers have attracted
considerable critical interest from various internet
bloggers, most particularly from those who seem to display
their Neo-darwinian dogmatism like a badge of honour. An
unfortunately frequent feature of these blogs is that they
mix the dogmatism with insulting, even libellous, language.
See also dogmatism.
The best advice I can
give to them and their readers is ‘look before you leap’.
Firing off standard ready-made criticisms before carefully
reading the articles or listening through the videos to the
point at which those common criticisms are clearly dealt
with simply perpetuates misunderstandings. In this section I
deal with examples written by critics who are clearly
‘firing off from the hip’ since the points they make are
already extensively dealt with in the lectures and articles.
They only had to read or watch a bit further.
Darwin was wrong?
“Here we go again: someone arguing that DARWIN WAS RONG”
(sic).
This comment could
not be more wide of the mark since I argue that Darwin was
(largely) right! See
Darwinism.
Enough said.
This kind of
criticism illustrates a common tactic by some
Neo-Darwinists, which is to ‘recruit’ Darwin to their cause.
Darwin was not a Neo-Darwinist and he even admired Lamarck.
It is a simple historical mistake to conflate Darwinism with
Neo-Darwinism.
Random variation. One critic
complains
“What we mean by “random” is that mutations occur regardless
of whether they would be good for the organism.”
Precisely so, and if
the writer had read on just a little bit further (at the end
of the same paragraph in which ‘random’ is first mentioned!) he would find
my precisely equivalent statement: “I will use the
definition that the changes are assumed to be random with
respect to physiological function and could not therefore be
influenced by such function or by functional changes in
response to the environment. This is the assumption that
excludes the phenotype from in any way influencing or
guiding genetic change.”
The same ‘rapid fire’
mistake through not reading carefully is made by another
blogger who wrote
“His most moronic claim by far is the one on mutations not
being random.”
The extraordinary
feature of this kind of criticism is that the potentially
functional nature of some of the variations
is the central
theme of the articles and lectures. It is hard to miss that
theme if one reads the article even cursorily, and it
features towards the beginning of the IUPS2013 lecture. At
7:00 minutes the transcript reads “It is important here to
ask what we mean by random, because it is not just a
question whether the changes are truly random … but rather
whether the changes are functionally relevant. That is the
key.” At 7:30 minutes the transcript even uses the
definition in the published article exactly as quoted above.
It forms one of the slides of the lecture. In the 2012
lecture in Suzhou, China, it is made clear at 6:48 minutes
and again towards the end of the lecture that the key lies
in functionally significant changes. At 34:19 the transcript
reads “If functional changes in the adult can be inherited,
and therefore a target for natural selection, then
physiology – which is the analysis of function – IS highly
relevant to evolution.” It is hard to see how these points
could have been made any clearer in the article and
lectures. Failure to notice them implies a failure to read
or watch carefully enough.
Notice again the
gratuitous insults. There are even more grossly insulting
and libellous remarks on the blog.
For more on the
question of functionally relevant genome changes see
Relevance to Physiology. See also
Randomness and
Function.
Inheritance of acquired characteristics.
“I know of not a single adaptation in organisms that is
based on such environmentally-induced and non-genetic
change.”
It is hard to take
this kind of comment seriously. It reveals someone who is
not keeping up with the literature. See
Trans-generational inheritance
for examples.
“For an adaptation to become fixed in a population or
species, it must be inherited with near-perfect fidelity.
And that is not the case for all environmentally-induced
modifications of DNA. They eventually go away.”
I give examples in
the lectures and article where this is clearly not true. RNA
transmitted changes independent of DNA have been followed in
planarians for 100 generations:
Rechavi O, Minevish G & Hobert O (2011).
Transgenerational inheritance of an acquired small RNA-based
antiviral response in C. elegans.
Cell
147, 1248–1256.
The recent Apobec1
deficiency example from Nadeau’s laboratory is also very
clear in showing “heritable epigenetic changes [that]
persisted for multiple generations and were fully reversed
after consecutive crosses through the alternative
germ-lineage.”
Nelson VR, Heaney JD, Tesar PJ,
Davidson NO & Nadeau JH (2012). Transgenerational epigenetic
effects ofApobec1 deficiency on testicular germ cell tumor
susceptibility and embryonic viability.
Proc Natl Acad Sci
U S A 109, E2766–E2773
Notice also the very
high quality of the journals (Cell
and PNAS) in which
these ground-breaking studies were published.
From a much earlier
period (mid 20th century), the
environmentally-induced changes investigated by Waddington
became locked into the DNA after about 14 generations and
therefore became essentially permanent. He called this
process genetic assimilation and it was one of Waddington’s
great, but largely ignored, contributions.
See
Trans-generational inheritance for further examples
and references. To quote my article: Some of “these effects
persist for many generations and are as strong as
conventional genetic inheritance.”
Cells are transitory.
“Cells
are transitory, and DNA is not.”
This is a common
mantra, copied from
The Selfish Gene. It is linguistically incoherent and
factually incorrect. See
Immortal Genes?
Jumping genes.
“These kinds of changes are rare except in bacteria.”
Barbara McClintock
received her Nobel Prize for jumping genes in 1983 for her
work on plants. The examples I give in the lecture show large-scale genome
reorganisation across a whole range of
vertebrates.
Cross-species transfers are indeed rare except in bacteria.
But, after all, speciation itself is rare, and there are
plenty of documented examples of horizontal gene transfer
from bacteria to various eukaryotes. Recent examples
include:
Redrejo-Rodríguez, M,
Muñoz-Espín, D, Holguera, I, Mencía, M, Salas, M, (2012).
Functional eukaryotic nuclear localization signals are
widespread in terminal proteins of bacteriophages.
Proc. Natl. Acad. Sci. U.S.A.
109: 18482–7. “These findings show a common feature of
TPs from diverse bacteriophages targeting the eukaryotic
nucleus and suggest a possible common function by
facilitating the horizontal transfer of genes between
prokaryotes and eukaryotes.”
Acuna, R. et al (2012) Adaptive
horizontal transfer of a bacterial gene to an invasive
insect pest of coffee.
Proc. Natl. Acad. Sci. U.S.A.
109: 4197–4202. “We identified a gene (HhMAN1) from the
coffee berry borer beetle,
Hypothenemus hampei,
a devastating pest of coffee, which shows clear evidence of
HGT from bacteria.”
Where the phenomenon
is common (in prokaryotes) speciation is so rapid that
microbiologists no longer find the species concept helpful.
The more (and only)
serious point made by this particular critic is whether the
Modern Synthesis has been modified to take account of these
‘big mutations’:
“The Modern Synthesis has expanded a bit to take account of
these new genetic findings, which only recently became
possible. But their discovery hardly invalidates the
Synthesis.”
I think that is a
matter of judgment. Some of the new findings are
incompatible with the Modern Synthesis. See
New or Extended
Synthesis.
Origin of species. A common criticism
is that speciation has
been observed. Precisely so, and I don’t question that. The
relevant question now is what the mechanisms were. It is
common in Neo-darwinist discourse for people to conflate the
fact that speciation clearly has and does occur with the
specific Neo-darwinist interpretation of the mechanism by
which it happens. See
Origin of Species.
This is part of a pattern in which any evidence for the fact
of evolution is counted as evidence for Neo-darwinism. To
say the least, this is sloppy thinking.
And, finally……..
Good advice to Denis Noble.
“He might try discussing his ideas with other evolutionists
and listening to their responses.”
I couldn’t agree
more! I have greatly enjoyed doing so for around 40 years.
The list of leading Evolutionary Biologists with whom I have
interacted must now be around fifty, and they involve some
well-known Neo-darwinists, including Dawkins, Maynard Smith
and Wolpert. See
Johnny-cum-lately.
Conclusions
The critical
reactions so far are so extraordinarily wide of the mark
that they are simply hilarious – almost a parody of academic
criticism. Yet they weren’t intended to amuse, they were
meant in all seriousness.
They attack positions
that it is obvious I do not hold. That could have been clear
from reading the articles or viewing the lectures. If the
critics did that, they must have done so with remarkably
closed minds or they failed to follow the logic through to
their clearly stated conclusions. To miss the main statement
when it is in the same paragraph as the sentence being attacked is breath-taking. It
is an elementary principle of scholarship to read an article
fully before writing a criticism.
The need to use
abusive libellous language also speaks volumes about the
confidence these people must have in their own scholarship.
So, are these critics
just ‘saloon bar’ opinionators, or teenagers having fun on
the internet? No, they are full university professors at
major universities. And they are serious. That is what is
both interesting and alarming, and why I have taken the time
to answer them seriously. But how could such a major area of
science have generated such philosophically naïve
dogmatism?
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The MUSIC of Life: Biology Beyond the Genome ©Denis Noble |