Thursday, September 11, 2003

Funny Genes

There was once a time in my life when I had four dogs living with me on a 40-acre farm in the middle of nowhere. One of these dogs had been adopted from the pound. The other three showed up as scrawny strays, and they adopted me.

They were all males, and three of them were neutered. Fort was the newest arrival and I simply had not gotten around to it yet. Besides, he was such a wimp... he was never going to be getting anyone pregnant. He had this incredibly endearing/annoying habit -- Whenever he came up to the other dogs in the group, he would crouch down in a submissive way and do this rapid licking thing around their lips. I had never seen anything like it. It drove the other dogs nuts initially, but eventually they came to tolerate it.

One day a very shy female dog showed up. She was terrified of people and would not come within a hundred feet of me. But apparently she got along OK with the other dogs because she hung around for weeks. Apparently she got along with Fort very well, because she eventually had puppies. The way you could tell that Fort was the father was because several of the puppies had this same submissive rapid licking habit. It was not "nurture," because Fort was gone by the time they were born. It was "nature."

How could such a weird characteristic be inherited? Is there a gene (or combination of genes) in the dog genome that encodes for "weird submissive rapid licking behavior"? Apparently there is. And when you think about it, it makes sense that weird behaviors in dogs are inheritable. All border collies, for example, tend to be good herders. They have a set of herding behaviors wired into their brains, and that programming is inherited. So somewhere in the dog genome there is a pattern of genes that encodes for "herding behavior". People breed border collies to accentuate that pattern.

It happens in people too. For example, my father-in-law has a distinctive thing he does with his elbow when he is climbing steps. My wife inherited it and does the same thing. There's a gene, apparently, that encodes for "weird elbow thing while climbing stairs." Similarly, I once met an adopted boy whose biological father was a baseball player. The boy didn't know that, but his adoptive parents did. Even at age 6 this kid was huge and could handle a bat like you would not believe. So there is a gene or a set of genes for being able to whack a baseball out of the park.

As scientists unravel the human genome, right now they are focusing on practical things. Mostly they are trying to cure genetic diseases or find the fountain of youth, which makes sense. But after all the practical stuff gets figured out, perhaps graduate students will be doing their theses on very strange inheritable features. Like the gene that lets you whack a baseball, or the gene that makes you hold your elbow a certain way, or the gene that causes you sneeze three times in a row, or the gene that lets you invent lots of things. There are going to be some genes that really surprise us. It is when we allow parents to put all these millions of random genetic possibilities together in any combination that things will get really interesting...

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