Thursday, May 25, 2006

Nature is Full of Surprises

From Nature News, we hear of another twist in the story of inheritance:

Mutant mice challenge rules of genetic inheritance
DNA's cousin, RNA, may also pass information down the generations.

Helen Pearson

In a discovery that rips up the rulebook of genetics, researchers in France have shown that RNA, rather than its more famous cousin DNA, might be able to ferry information from one generation of mice to the next.

DNA has long been credited with the job of passing traits from parent to child. Sperm and egg deliver that DNA to the embryo, where it ultimately decides much of our looks and personality.

The new study in Nature1 thrusts RNA, DNA's sidekick, into the limelight. It suggests that sperm and eggs of mammals, perhaps including humans, can carry a cargo of RNA molecules into the embryo - and that these can change that generation and subsequent ones.

"It's a very exciting possibility," says Emma Whitelaw who studies patterns of inheritance at Queensland Institute of Medical Research in Brisbane, Australia. "DNA is certainly not all you inherit from your parents." [...]
We already knew that mitochondrial DNA could play a role, albeit a small
role, in the process of inheritance.  

Spotty mice flout genetics laws, on the BBC site, is another article on the same topic.  The Washington Post has a version, here.  

When I hear of things like this, I am reminded of how little we know about the details of the functioning of even fairly simple processes in biology.  Think about inheritance, which is the transfer of a defined set of information.  Then think about the operation of the human brain, which has something like 1015 synaptic connections.  

Now, I am going to write something very un-scientific.  

Proponents of Intelligent Design might look at the subtleties of inheritance, or the vast complexity of the brain, and take those observations as evidence for their proposition.  As far as I can tell, though, their only argument is that the origin of species via evolution just doesn't seem right; it doesn't mesh with their intuition.  My intuition apparently works differently.  What I see is that scientists start out with a bunch of complex, seemingly-inexplicable phenomena, then one by one, make discoveries that explain more and more of what previously was inexplicable.  What my intuition tells me is that, eventually, science will come up with mundane (complex, perhaps, but still mundane) explanations for an ever-increasing percentage of things that formerly were awe-inspiring.  From that, I conclude that the mere existence of seemingly-miraculous things can only be taken as evidence of limitation in our knowledge and understanding.  It does not mean anything more.