He’s Ba-a-a-ck: Lamarck Puts Pressure on Darwin – and ID, Too?
To historians of evolutionary theory, Lamarck is a 19th-century loser. His hypothesis of “inheritance of acquired characteristics,” according to high school textbooks and common knowledge, was debunked by experiment, and overturned when Darwin proposed natural selection as a mechanism for evolution. Why, then, does Massimo Pugliucci (Dept. of Ecology and Evolution, State University of New York at Stony Brook, NY) give Lamarck good press in a book review in Nature?1 Why does he put Darwin on defense, charging that a “broader view of inheritance puts pressure on the neo-darwinian synthesis”?
Pugliucci favorably reviewed the book Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life by Eva Jablonka and Marion J. Lamb (Bradford Books, 2005), a “lamarckist” polemic:
The authors argue that there is more to heredity than genes; that some hereditary variations are non-random in origin; that some acquired information is inherited; and that evolutionary change can result from ‘instruction’ as well as selection. This may sound rather revolutionary, even preposterously close to lamarckism. But Jablonka and Lamb build on evidence from standard research in evolutionary and molecular biology, and their case should be examined on its merits, rather than being dismissed by a knee-jerk reaction. (Emphasis added in all quotes.)
He quickly quenches any alarm that he or the authors want to revive the kind of lamarckism that taught direct inheritance of acquired characteristics, or “direct adaptive feedback from the soma to the germ line” – for example, that a lumberjack’s strong arms would be inherited by his baby boy. “That version of lamarckism is dead,” he assures us, “killed off by our understanding of molecular biology, and nobody is attempting to revive it.” But that first meaning of lamarckism is not all that Lamarck taught:
The second meaning is actually closer to the core of Lamarck’s ideas, which are rarely, if ever, read by modern biologists. The suggestion is that some heritable, adaptive changes come not from natural selection, but from the action of evolved internal systems that generate non-random ‘guesses’ in response to environmental challenges. Examples are not hard to find, contrary to the assumed wisdom of standard neo-darwinism. Consider the existence of ‘hotspots’ that make mutations in certain regions of the genome much more likely than in others. Or the impressive ability of some bacteria to increase the mutation rate of a specific gene involved in the metabolism of a given amino acid when that amino acid becomes scarce in the environment.
Pugliucci acknowledges that “Jablonka and Lamb are surely taking a gamble in labeling their position as lamarckist,” but he sides with them in one shocking point: “they are correct to point out that no modern biologist is a darwinist in the sense Darwin would have understood – not least because Darwin included a lamarckian mechanism of the first (now frowned upon) type in his theory, as he had no solution to the problem of heredity” (see 10/14/2003 entry).
Having disabled the alarm, Pugliucci now offers the neo-lamarckism of Jablonka and Lamb as the evolutionary answer to the intelligent design movement:
If one accepts this bold, expanded version of heredity and evolution, it turns out that evolution can proceed very rapidly and phenotypic modification can precede genetic changes…. Indeed, changes at the genetic level will often simply stabilize adaptive modifications that are initiated through phenotypic plasticity [i.e., acquired characteristics], epigenetic control mechanisms, or behavioural and symbolic means [i.e., social/language communication from parent to offspring]. This is a framework that would greatly help to solve old problems in evolutionary biology, such as the origin of novel structures [see 08/20/2003 entry], and even the appearance of what ‘intelligent design’ proponents refer to, rather nonsensically, as ‘irreducible complexity’. This wouldn’t require the abandonment of neo-darwinism, but rather its expansion beyond what Ernst Mayr contemptuously labelled ‘bean-bag genetics’.
So Pugliucci offers not an either-or choice of lamarckism vs. neo-Darwinism, but an expanded synthesis beyond that thesis-antithesis dichotomy. For empirical support, he points to the “partial failure of the originally ultra-reductionist, gene-centred approach that gave us genomics,” saying that “the interesting stuff is going on at the level of large gene networks” [see 01/10/2003 entry], “not of individual genes, partly because there is widespread functional redundancy in the genome.” Presumably, this pool of functionality can be drawn on by environmental cues to optimize solutions to problems (see next headline).
Realizing his viewpoint will probably anger the hard-core selectionists, like Richard Dawkins (04/23/2003) and George Williams (05/31/2004), he draws on a defense, in closing, that has been used by several intelligent design proponents as strategic realism about changing the minds of the old guard:
The clamour to revise neo-darwinism is becoming so loud that hopefully most practising evolutionary biologists will begin to pay attention. It has been said that science often makes progress not because people change their minds, but because the old ones die off and the new generation is more open to novel ideas. I therefore recommend this and the other books I mentioned on the future of evolutionary theory to the current crop of graduate students, postdocs and young assistant professors. They’ll know what to do.
1Massimo Pugliucci, “Expanding evolution, ” Nature 435, 565-566 (2 June 2005) | doi: 10.1038/435565a.
They’ll know what to do, all right: they’ll chuck Chuck and baptize Jean-Baptiste into the dustbin of discredited prophets, and embrace intelligent design. Like Sutherland in the next article below, Pugliucci and his champions believe that specified complexity and optimization can emerge spontaneously, without purpose or direction, as long as there is a need. But that fallacy is not just with neo-Darwinism and its reductionist genomics; it is with any theory that fails to include information as a fundamental property of the universe. No combination of chance and natural law will produce information. Think of a blank DVD and one containing microscopic pits encoding the latest Star Wars movie: they have the same mass and physical properties. It is the information content that makes all the difference when you insert them into a DVD player. Similarly, to believe that the information content in the genome and in all the gene networks and epigenetic controls to which Pugliucci refers could have arisen by naturalistic means cannot be done without assuming naturalism at the outset. All our common experience teaches that information arises only from intelligent causes.
What this book review does, despite its dismissive ridicule of intelligent design, is strengthen the strategic posture of ID. It advertises the weaknesses of the Darwin camp to the enemy. The “clamor to revise neo-darwinism” has risen to a fever pitch within the Darwin camp, and can no longer be ignored, except by the Old Guard who have grown deaf with age. The phrase “irreducible complexity” has rattled the evolutionary generals:
“Quick: we need a counterattack,” they strategize. “How’s the neo-Darwinian antidote working?”
“Too weak,” the technician responds [see 10/14/2003 entry]; “Their weapons have developed immunity to it, and we’ve found it incapable of protecting our own soldiers. It’s not as potent as we thought it was.”
“Anything else in our strategic arsenal?” [See 07/23/2004 entry.]
“Nothing new, General. Most of our weapons were forged in the 19th century.”
“Well, then, did anything work well before Chairman Charles?”
“We could resurrect an older weapon used with partial success from time to time, even by Darwin,” a lieutenant responds [see 10/14/2003 and 07/02/2004 entries]. It was invented by General Lamarck.”
“We can’t use that; it’s broken. Everybody knows that.”
“We’ve got to do something, General. Let the young recruits try it and see if they can get parts of it to work this time.”
The intelligent design strategists, like Gideon spying around the tents of Midian (see Judges 7), are listening in on all of this. Can a loaf of barley bread overturn ten thousand tents? It can, either when the tents are made of wind held together by fog, or when there is supernatural power in charge. It appears the I.D. camp has both advantages.