Creationist Drivel – Weismann and Lamarck

Posts in this series.

Over at the FFF, remnant continues with his or her mission to absolutely ruin whatever is left of the forum, aided and abetted by the incompetent owner – whose behaviour is equivalent to paying $18,000 for a well-maintained car and parking it in a lake . However, remnant’s sociopathic behaviour in mindlessly pasting repeated snippets from the Institute of Creation Research doesn’t extend to finishing off his or her posts from the Vance Ferrell’s Evolution Handbook. I’ll have to conclude this series without remnant’s prompting.

Ferrell continues:

It is a remarkable fact that the basis of evolutionary theory was destroyed by seven scientific research findings,—before *Charles Darwin first published the theory…

August Friedrich Leopold Weismann (1834-1914) was a German biologist who disproved *Lamarck’s notion of “the inheritance of acquired characteristics.” He is primarily remembered as the scientist who cut off the tails of 901 young white mice in 19 successive generations, yet each new generation was born with a full-length tail. The final generation, he reported, had tails as long as those originally measured on the first. Weismann also carried out other experiments that buttressed his refutation of Lamarckism. His discoveries, along with the fact that circumcision of Jewish males for 4,000 years had not affected the foreskin, doomed the theory (*Jean Rostand, Orion Book of Evolution, 1960, p. 64). Yet Lamarckism continues today as the disguised basis of evolutionary biology. For example, evolutionists still teach that giraffes kept stretching their necks to reach higher branches, so their necks became longer! In a later book, *Darwin abandoned natural selection as unworkable, and returned to Lamarckism as the cause of the never-observed change from one species to another (*Randall Hedtke, The Secret of the Sixth Edition, 1984).

The Evolution Handbook is a remarkably poor piece of writing throughout, if evolutionfacts.com is anything like a fair representation, and, as the website is based directly on Ferrell’s work, it probably is. Yet the paragraph above is abysmal even by Ferrell’s standards. The only part that is correct is that Lamarckism (the passing on of characteristics acquired during life) has been disproved. Even if it was true that Darwin abandoned natural selection and embraced Lamarckism, this wouldn’t mean that modern evolutionary biology was based upon Darwin’s later thoughts. We have a good idea what Weismann thought as he wrote a book entitled Über die Berechtigung der Darwin’schen Theorie (On the justification of the Darwinian theory). According to Ferrell’s logic, therefore, Weismann denied Darwinism while supporting something else that he called Darwinian theory, which today we would call natural selection. Of course, Ferrell neglects to remark upon Weismann’s own thoughts on evolution, whereas normally he never loses an opportunity to poison the well by ensuring that people’s beliefs in other areas are given a mention. (Linnaeus was an “earnest creationist”, Wallace a “spiritist”).

Curiously, one page later from the link, Ferrell claims that “[m]odern evolutionists are ashamed of [On the Origin of Species], with its ridiculous arguments.” At this stage it is difficult to know just what point Ferrell is making, apart from perhaps a haphazard, inconsistent stab in the dark against non-believers. I wonder what it is that modern evolutionists are ashamed about if, as Ferrell says, Lamarckism is “the disguised basis of evolutionary biology”. This infers that On the Origin of Species did not reflect Lamarckian thought and therefore Weismann did not contribute to “destroy[ing] the basis of evolutionary theory”. In any case, from his wikipedia entry, his research confirming the falsity of Lamarkism is first recorded in 1883, twenty-four years after Darwin’s book. I can only guess that such details don’t particularly matter to Ferrell.

No modern evolutionary biologist would make the claim that Darwin got everything exactly right – he knew nothing of genetics, for example, so his theory of inheritance was incorrect. No modern evolutionary biologist would claim that we have all the answers today. It is a central principle of the scientific method that all knowledge thus obtained is provisional. This does not mean that such scientific knowledge is incorrect, but what it does mean is that it can never be regarded as completely certain while there is a potential disproof. For example, should a pigeon lay an egg which produces a cat, this would be a severe blow to evolutionary theory from which it probably wouldn’t recover. While this is an extreme and stupid example to display a point, it does indicate the provisional nature of scientific knowledge. While pigeons continue not to give birth to cats, this aspect of evolutionary theory does not change, and the basis of evolution in this area remains as accepted scientific knowledge. The best science is the science that disproves consensus or orthodoxy, because only when orthodoxy is overthrown can we improve our knowledge – creationists should take heed of this difference between scientific and religious ways of thinking.

So what is this evolutionary theory that Ferrell claims is destroyed? Ferrell doesn’t even appear to know what it is himself.

Evolution, which is defined here as a process that results in heritable changes over time,  is not a particularly new concept. Some of the Ancient Greeks, Chinese, Islamic scholars and even St Augustine, among others, had proposed that biological species were not fixed. But it was only with the dawn of the Enlightenment, and the early taxonomists, notably John Ray and Linnaeus, that modern evolutionary theory finds its earliest roots. The fact that there are similarities between species led to the thought that there were biological relationships between at least some of them. Far from disproving Darwinism, as Ferrell asserts, the work of Linnaeus is essential to understanding it.

Following taxonomy, the early proponents of evolution included Charles Darwin’s grandfather, Erasmus Darwin and Jean-Baptiste Lamarck (1744-1829). Erasmus Darwin and Lamarck were notable for their identification of an species’ environment as a prime factor in determining its characteristics. Lamarck is known today for his theory of acquired heritable characteristics, which is nowadays called Lamarckism. The best-known example of Lamarckism is the giraffe’s neck, which Ferrell has used as an example. According to Lamarckism, a giraffe would stretch its neck to reach higher leaves, thereby acquiring a longer neck, and this change would then be passed on to subsequent generations. A species could also lose a characteristic it already had through disusing it. As even Ferrell points out, this theory has been almost completely discredited, especially in the light of units of inheritance as described by genetics, but even in Lamarck’s day, there was much evidence against it.

That is not to say that Lamarck should be completely ignored. The role of environment in selection has not been discarded, and is included in several modern or recent evolutionary theories. For this reason if no other, Lamarck is important in the history of evolutionary thought.

There are many differences between Lamarckism and Darwinism – and modern evolutionary theory is vastly more complex than either. But the major difference between the two is that with Lamarckism, species would pass on characteristics acquired in their lifetime, whereas Darwinism would favour those members of a species that already had the required characteristic. In the example above, Darwinism predicts that giraffes that already had longer necks would be more likely to survive in times of food scarcity, and therefore would be more likely to pass on their characteristics than giraffes with shorter necks. Darwinism also predicts that, firstly, apart from twins no two individuals of higher species are identical, and secondly, that changes from generation to generation are random, and slight. Modern studies of genomes strongly support this conclusion – anyone, even a creationist, who thinks that DNA evidence is useful for crime detection in certain circumstances is supporting the central premise of Darwinian theory, even if Darwin himself was unaware of genetics and DNA. The central difference between Lamarckism and Darwinism is that under Lamarckism, evolution is directed towards a goal whereas Darwinism sees no such direction. Creationists often wrongly attribute this goal-centredness to Darwinism.

Regarding the mechanism of heritability, Darwin was as wrong as Lamarck. He was careful to describe his thoughts on heritability (pangenesis) as a hypothesis rather than a theory. There seems little doubt that Lamarck, by identifying the link between heredity and evolution, influenced Darwin somewhat. He didn’t “return to Lamarckism” as quoted as Ferrell, nor did he “abandon natural selection”.

Weismann, not that Ferrell would have anyone know, was a big supporter of Darwin. In his book, On the Justification of the Darwinian Theory, he comes as an early opponent of creationism.  However he did disagree with both Lamarckian and Darwinian ideas of hereditary mechanisms. He had an advantage in that by his day microscopes that could investigate individual cells were available. Weismann is best known for his proposal of germ plasm theory, which states that certain cells only controlled heredity. In effect, Weismann had identified genes, and although his understanding of them is far removed from modern genetics, the neo-Darwinian synthesis that has led to modern evolutionary biology starts with Weismann.

As I’m not too familiar with Weismann, I suggest some further reading: Answers.com

Modern evolutionary theory incorporates Darwinism (descent by natural selection) to a large degree, although there are other influences. However, I doubt very much whether any biologist could be found that would support the idea that giraffes can change their characteristics in their own lifetimes and then pass those characteristics down along generations. Although some micro-organisms have been thought to have this potential, Lamarckism is not the basis of modern evolutionary biology, hidden or otherwise.

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: