Monday, March 16, 2009

Food for thought: DNA is not the whole story

DNA is not the blueprint for life. Sorry. If you put a piece of DNA in a jar, it will do nothing. It's only part of the picture. In order to function, DNA needs to be in a compatible living cell where all the required chemicals are available. But if you take a fertile living cell and put it in a jar, under most conditions it will die. Each cell can only survive in a certain range of temperature, pH, gravity and pressure, and needs just the right nutrients to survive.

Does DNA contain the information to create its own optimum environment? No. It is only part of the blueprint of life, and it has a lot of dependencies. It is certainly where most of the information is stored, but there's a bigger picture to ponder.

DNA is badly misused in science fiction, especially in TV and movies where everything has to happen in a hurry. If we beamed a human genome to an alien civilization, would they be able to make human? No. But if we beamed them a complete scan of a cell, and how to nurture it, maybe (just maybe) there would be a chance of success.

Monday, March 09, 2009

Food for Thought: Sex and mutations

Sexual reproduction is a line of defense against mutations. If one parent has a damaged gene, the other parent (hopefully) has an undamaged gene. If all genes had equal weight, there would be a 50/50 chance of the offspring getting the undamaged gene. In reality, genes can be dominant or recessive, and other factors are probably at work.

The natural next question is how creatures started shooting genetic material at each other in the first place.

There are many events in the ocean of massive releases of genetic material. That some creatures found ways to get up close and make a more personal delivery does not surprise me.

I have seen pine trees release clouds of pollen at the touch of the wind. It boggles my mind that some of those spores might land on a receptive cone and start the long process that makes a seed. It seems like such a waste to have the rest of the cloud fall dead somewhere. It is also pretty wild that I can pick up seeds when I walk in the woods, and hold entire potential trees in my hand.


Note: "Food for thought" is going to be an ongoing series of speculations and science commentary.