Creationist Drivel – Mendel

Posts in this series.

I’m in danger of catching remnant up, so sparingly is he releasing his eagerly-awaited information.

Before I look at Gregor Mendel, just  couple of points:

Firstly, I discovered that the Evolution handbook author is one Vance Ferrell. In future I’ll refer to him by name. Ferrell is a prolific writer with a peculiar style. He is a creationist, but also has written in support of “natural remedies” and against innoculation, the evils of rock music, the “End Times” and curiously, the story of the Bounty.

Secondly, I thought some more about entropy. The Second Law of Thermodynamics has many applications but essentially states that with time, overall entropy will increase. Creationists have taken this to mean that there is a physical law that states that complexity will tend to decrease – albeit their interpretation is faulty. Now the reason that complexity increases, in the natural world, is that the Earth / solar system is not a closed system, and allows for local increases in complexity at the expense of a general increase in entropy. So non-creationists have a workable explanation. Not so the creationists. They are of the opinion that all physical and chemical laws are god-created, maintained and sanctioned, rather than a feature of physical universe. Therefore if they accept that God created the second law they must also accept that the second law doesn’t work, as on Earth there are many examples in which there is no tendency towards higher entropy – as Route_70 pointed out, embryology is one of them. Therefore God created a law that he broke and continues to break. How are we to even define a physical law in such circumstances?

Moving on, Gregor Mendel:

Gregor Mendel (1822-1884) was a Creationist who lived and worked near Brunn (now Brno), Czechoslovakia. He was a science and math teacher. Unlike the theorists, Mendel was a true scientist. He bred garden peas and studied the results of crossing various varieties. Beginning his work in 1856, he concluded it within eight years. In 1865, he reported his research in the Journal of the Brunn Society for the Study of Natural Science. The journal was distributed to 120 libraries in Europe, England, and America. Yet his research was totally ignored by the scientific community until it was rediscovered in 1900 (*R.A. Fisher, “Has Mendel’s Work Been Rediscovered?” Annals of Science, Vol. 1, No. 2, 1936). His experiments clearly showed that one species could not transmute into another one. A genetic barrier existed that could not be bridged. Mendel’s work laid the basis for modern genetics; and his discoveries effectively destroyed the basis for species evolution(*Michael Pitman, Adam and Evolution, 1984, pp. 63-64).

It maybe a small point but Ferrell has it wrong again. On the Origin of Species was published in 1859. Mendel’s work came out in 1865. Therefore the theoretical basis for evolution was not disproved prior to publication of Darwin’s book. If disproved it was.

Ferrell then makes a distinction between “true scientists” and “theorists”. Now anyone that knows anything about science would tell you that the purpose of science is to produce scientific theories, which are, according to the American Association for the Advancement of Science a scientific theory is a “...well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not “guesses” but reliable accounts of the real world.” Obviously, in general discourse we use the word theory is a quite different way – as an “educated guess”. However, it should be clear enough that theories are not guesses but depend on a combination of reliably observed facts, models, logical inferences, tested hypotheses and other theories, not to mention scientific laws. It’s also commonly supposed among the scientifically uneducated (and creationists in particular) that a “really good theory” achieves the status of a law. This is incorrect. In the hierarchy of scientific discovery theories sit above laws, facts and hypotheses rather than being subservient to them. As a writer on science, one would think that Ferrell wouldn’t fall into that trap. It’s hard to know whether he’s dissembling or just ignorant.

When I learned science at school, evolution was off the agenda. I see that nowadays in England and Wales students are introduced to evolution at ages 14-15, which, in the light of (the Christian) Dobzhansky’s “Nothing in Biology Makes Sense Except in the Light of Evolution” is perhaps a little late, but an improvement in things from my day. We did, however, study the Mendelian theory of inheritance. Note the use of the word “theory”. At this rudimentary level we learned that there was a mathematical / statistical basis to inheritance – we understood that while most people had brown eyes, brown-eyed parents could produce blue-eyed children, for example.

It is true that although Mendel was aware of the work of Darwin, Darwin had no such awareness of the work of Mendel. From Darwin’s perspective this is a shame, because Darwin had no idea of the mechanism of selection. Indeed, Darwin’s ally, Thomas Huxley, held on to a saltationist view to his death – a view that Mendelian theory completely (and correctly) rejects.

It’s true that Mendel’s work took some time to be accepted. This is partially because Mendel effectively retired from science to take up administrative duties within his abbey and also because his findings appeared to contradict some reliable observations. We now know that Mendel was right, but he didn’t know just how complex genetic variation is. There are very few characteristics that depend on the composition of  just one gene (Mendel’s unit of inheritance), and most of these are connected to diseases such as Huntingdon’s Chorea or sickle-cell anaemia, but much more commonly, observations show the related actions of several genes together with environmental factors.

Mendel’s work was rediscovered by William Bateson, among others. Bateson disputed the Darwinian theory of gradual, small incremental change and hoped to use Mendel’s work to demonstrate the correctness of his hypothesis. Bateson, like Huxley, didn’t dispute evolution per se but hoped to show that evolutionary change took place in much larger steps than Darwin had proposed. So even an anti-Darwinian such as Bateson didn’t dispute that Mendel’s theory supported evolution. Following Bateson’s work, a number of scientists undertook their own research, including William Castle of Harvard. Initially a supporter of Bateson, Castle’s work with hooded rats, again using Mendel’s theories, revealed that many genes were modifying certain characteristics and therefore small degrees of continuous variation were sufficient for evolutionary change. Castle is most famous for his his work with the fruit fly Drosophilia, which is now the single most-studied species in evolutionary biology, and the studies have further revealed the reliability of both Mendelian and Darwinian theory. While it’s fair to say that Mendel’s original studies were over-simplistic, he did endow biology with a mathematical basis for genetic change, and therefore his work is essential in understanding evolutionary theory, as it has developed. In no way did Mendel discredit or disprove Darwin’s theory, but added to it to all our benefit. It’s just as true to say that in biology, nothing makes sense except in the light of genetics.

Ferrell says that [h]is experiments clearly showed that one species could not transmute into another one. A genetic barrier existed that could not be bridged“. Quite where this comes from it is hard to say. There is no need to change species in order to effect a transmutation. I suppose that creationists would say that Mendel observed no new information, and in their minds they have a false idea that evolutionary theory demands that new (genetic) information is necessary. In fact genetic information can just as easily be lost and evolution still occurs. Also when considers that many species have strong genetic similarities (typically humans share about 98% of their genome with chimpanzees and about 85% with mice) it’s hard to think what Ferrell means when he speaks of “genetic barriers”.

Far from destroying the basis for species evolution, Mendelian theory, as it has developed, is essential to understanding it.

Evolution Handbook Fail. Again

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: