The Thing about Science

Just when you think you "know" something, you find out that you don't:

Mendel's Law May Be Flawed

Associated Press
11:22 AM Mar. 23, 2005 PT

Challenging a scientific law of inheritance that has stood for 150 years, scientists say plants sometimes select better bits of DNA in order to develop normally even when their predecessors carried genetic flaws.

The conclusion by Purdue University molecular biologists contradicts at least some basic rules of plant evolution that were believed to be absolute since the mid-1800s, when Austrian monk Gregor Mendel experimented with peas and saw that traits are passed on from one generation to the next. Mendelian genetics has been the foundation of both crop hybridization and the understanding of basic cell mutations and trait inheritance....

Scientists said the discovery raises questions of whether humans also have the potential for avoiding genetic flaws or even repairing them, although they said the actual proteins responsible for making these fixes probably would be different in plants....

"This means that inheritance can happen more flexibly than we thought," said Robert Pruitt, the paper's senior author.

Does this news vindicate the long-scorned Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (1744-1829)? According to Wikipedia,

Lamarck is remembered today mainly in connection with a discredited theory of heredity, the "inheritance of acquired traits", but Charles Darwin and others acknowledged him as an early proponent of ideas about evolution. In 1861, for example, Darwin wrote:

"Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801. . . he first did the eminent service of arousing attention to the probability of all changes in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition."

Lamarck's own theory of evolution was in fact based on the idea that individuals adapt during their own lifetimes and transmit traits they acquire to their offspring. Offspring then adapt from where the parents left off, enabling evolution to advance. As a mechanism for adaptation, Lamarck proposed that individuals increased specific capabilities by exercising them, while losing others through disuse. While this conception of evolution did not originate wholly with Lamarck, he has come to personify pre-Darwinian ideas about biological evolution, now called Lamarckism.

And so the wheel of science turns.