Celebrating Darwin – looking for the ‘third wave’ in evolution

For the Darwin bicentennial, Seed magazine has an excellent collection of special articles.

One of the most seminal, to my mind, is Eva Jablonka’s call to integrate much more epigenetics into the modern neo-Darwinian synthesis.

Things like Lynn Margulis’ symbiosis have already been incorporated, as a big enough issue. But, as Jablonka notes herself, epigenetics would more directly challenge the integration of genetics into Darwinism that brought about the neo-Darwinian synthesis as the “second wave” of modern evolution.

After starting by noting the evidence is accumulating for more than just DNA being involved with evolution, Jablonka gives us a definition:

Epigenetics is a term that includes all the processes underlying developmental flexibility and stability, and epigenetic inheritance is part of this. Epigenetic inheritance is the transmission of developmental variations that have nothing to do with changes in DNA base sequences. In its broad sense, it covers the transmission of any differences that do not depend on gene differences, so it encompasses the cultural inheritance of different religious beliefs in humans and song dialects in birds. It even includes the developmental legacies that a young mammal may receive from its mother through her placenta or milk — transmitted antibodies, for example, or chemical traces that tell the youngsters what the mother has been eating and, therefore, what they should eat. But epigenetic inheritance is commonly associated with cellular heredity, in which differences that arise among genetically identical cells are transmitted to daughter cells.

She then notes that epigentics is connected to cell differentiation within an embryo, and even more, once differentiation starts, how kidney cells “reproduce true.”

Next, she notes that more and more evidence has accumulated for the transference of epigenetic traits between organisms.

From there, she goes to the mother lode of the need to go to a “third wave” of evolution:

Induced and heritable epigenetic change may guide genetic changes.

That’s one big reason I score down, and scorn, modern Pop Evolutionary Psychology, too. It takes no account of epigenetics.

Anyway, read the full story for an idea of where evolutionary research is headed, and where its main theorists need to be focused.

Lincoln-Darwin bicentennial musical selections

For Lincoln, the obvious selection is Aaron Copeland’s “Lincoln Portrait.”

For Darwin? Why, Saint-Saëns’ “Carnival of the Animals,” of course. Complete with the movement on fossils.

Celebrating the Darwin bicentennial – personal-professional reflections

This is the second half of my newspaper column for this week, adapted and expanded.

Hundreds of millions of Americans will celebrate the historic milestone of the Abraham Lincoln birth bicentennial Feb. 12. Especially with the connections between Lincoln’s role in ending slavery and Barack Obama’s recent inauguration as the nation’s first African-American president – not to mention both of them being from Illinois – the celebrations take on an additional historic depth.

But, for Americans in the know, there’s a second birth bicentennial to be celebrated on the same day. The person in question isn’t American, but has just as much importance as does Lincoln.

In one of those quirks or twists that make history so interesting, Charles Darwin was also born Feb. 12, 1809.

And, he and Lincoln have some connections in spirit or character.

Both of Darwin’s grandfathers were active in the British movement to abolish slavery in its colonies and possessions. And, Darwin started his study on the theory of evolution in part to refute people who claimed whites and blacks had enough different heredity to be different races, with whites as a superior race.

I have already looked at Lincoln.

Now, Darwin.

The biggest thing that people get wrong about him begins with bad language use by pollsters and much of the media.

First, “theory,” as in “theory of evolution” – or, “theory of gravity”; more on that in a minute – does not mean “theoretical” in scientific usage.

Second, the theory of evolution is not something one “believes in.” Professional scientists always talk about “accepting” (or not) the theory of evolution.
Let’s spin out the analogy with the theory of gravity. Have you ever heard anybody talking about “believing in the theory of gravity”? I didn’t think so.
Third, evolution is not atheistic. And, Darwin wasn’t personally an atheist.
In his famous “warm little pond” comment in 1871, he did speculate about the origin of the building blocks of life from purely chemical means, but made no intellectual commitment to the idea, known as abiogenesis.

Today, many professional biologists have no problems accepting the theory of evolution while still holding religious beliefs.

Fourth, evolutionary theories started before Darwin.

Actually, Jean-Baptiste Lamarck, he of the “inheritance of acquired characteristics,” proposed a comprehensive theory of evolution 50 years before Darwin.
And, evolutionary ideas were in the air already 2,500 years before that, starting with the Greek philosopher Anaximander.

Fifth, Darwin hasn’t been refuted.

True, he knew nothing about units of heredity. Gregor Mendel’s work with pea plants wasn’t done until after Darwin published “On the Origin of Species,” and there’s no indication he had heard about it even when he wrote “Descent of Man,” although Mendel had a German translation of “Origin” later in his life. In the light of Mendel’s work, followed by the discovery of chromosomes, then genes, and the use of statistics, in population genetics, Darwin’s theory has been expanded and refined, not refuted.
As for claims pushed forward today about things like “irreducible complexity,” on the other hand, those ideas have been refuted, every time a new claim is brought up.

That said, some ideas that have sprung up under influence of the theory of evolution have been refuted.

Social Darwinism, whether in a financial sense, like that of the robber barons of the Gilded Age or investment bankers of today, or as “proof” of some other social distinction, is totally untrue. Evolutionary psychology, the claim that human psychological characteristics have evolved, is often shaky and sometimes makes overblown claims.

But the basic edifice is far more intact. From the modern theory of evolution, incorporating genetics into Darwin’s original idea, we’ve learned about categorizing species, how bacteria and viruses evolve to infect people (and how we might vaccinate against that) and much more.

Darwin, not outdated, still prescient today

In fact, in many ways, biology had to spin to catch back up to Darwin, after naively rejecting his ideas on the mechanism of evolution — primarily natural selection but also sexual selection and even some sort of group selection.

He even appeared to have some good ideas about some form of evolutionary psychology:

Darwin “never felt that morality was our own invention, but was a product of evolution, a position we are now seeing grow in popularity under the influence of what we know about animal behavior,” Frans de Waal says. “In fact, we’ve now returned to the original Darwinian position.”

Perhaps part of why Darwin’s mechanisms were rejected is that they didn’t always fit into late 19th century ideas of “progress.” For that matter, I charge that ideas like Pop Evolutionary Psychology may still get snared in issues of “progress.”

Celebrating Darwin – what is a species?

It may well turn out that Darwin’s own somewhat vague answer is actually better than some overdefined answers today.

No offense to Ernst Mayr, but it does seem that reproductive isolation may be too limiting of a definition. ANY purely reproductive definition may be too limiting. Perhaps, to riff on Richard Dawikins’ “The Selfish Gene,” it’s a case of a taking a gene’-s eye view of an organism-level issue.

I agree with Darwin that we can’t always define something like “species” as precisely as we might like. Perhaps, per Dan Dennett this time, evolutionary biologists have been practicing “greedy reductionism” here, not just reductionism.

In a somewhat related issue, evolutionary biologists are working to determine just how robust the evolutionary tree of life is.

Science illiteracy not confined to US

In a survey done in Great Britain as part of the run-up to the Darwin bicentennial, half of British said they don’t believe in evolution.

First, a side note. The theory of evolution is NOT something you “believe in” any m ore than is the theory of gravity. Most people don’t understand well how the word “theory” is used in science; that said, try presenting the analogy I just mentioned of the two theories to your hard-core creationist or IDer, and you’re sure to get a crash course in obfuscation.

As British science instructor James Williams notes, you “accept” evolution, you don’t “believe” it.

That said, more than one-fifth of Brits not only don’t accept evolution, they actually believe creationism.