Friday, October 26, 2012

"Lamarck and the Missing Lnc" - from The Scientist

Nice overview by Kevin B. Morris in the cover story of The Scientist, Lamarck and the Missing Lnc, of the work in epigenetics which is challenging the basic tenet of evolution that random mutation is the only source of change in genetics.

As I understand it, serious challenges to an individual's survival may cause heritable changes in the ability of the DNA to express particular regions of the genetic code.  "Long noncoding RNAs (lncRNAs) are transcripts generally expressed from regions of 'junk' DNA that are not thought to code for proteins" but now it seems they may be controlling the expression of the genes, controlling when and how much of a particular protein is produced by the cell.  Suppression of the expression caused by an environmental challenge may be heritable.
(See images 1: The Epigenetic LNC, 2: A Mechanism for a Targeted Change, and 3: Directing Evolution)

Back in the dawn of genetics, Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck, often known simply as Lamarck, theorized that traits formed in an individual's life would then be passed on to it's offspring; for example, a giraffe could develop a long neck because it stretched it reaching for forage up high, and their offspring would inherit longer necks as a result. Lamarck's theory has been a prime example of a thoroughly de-bunked scientific theory for decades.

These developments don't exactly support Lamarck's theory, but there is more than a whiff of Lamarckism about them.  And, there do seem to be holes in the strict Darwinism now.  Exciting times!

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