Friday, April 25, 2008

National DNA Day

I hope you are already aware that today is National DNA Day. And the day is half gone at the time of this posting... tsk! Now, if there is one thing we can all celebrate - and I do mean ALL - it is Deoxyribonucleic Acid! Gracious, we would be nothing without it, and Earth would be quite a different place. So give thanks for your genetic code, much of which you share in common with the rest of living organisms (evolution is a MARVELOUS thing). Squirmy worms, flying fowl, leaping lemurs... and us! Not so different on a molecular level, really.* There's still time to chat online about all things DNA-ish. Talk with the scientists at

*How similar are we to those other species? I'm glad you asked! Here's the answer I received to that question on
Mary Schueler, Ph.D. : Generally, human DNA is most similar to more closely related species like the great apes - chimp, gorilla, and orangutan. These are more closely related to us in evolutionary time. Species that have been separated from us for longer periods of time share less similarity. As you compare with species farther away from us on the evolutionary tree, we observe that DNA sequences that code for proteins are conserved while other sequence is not. This is thought to be due to the necessary function of the proteins in the life of the cell. If the sequence changes, the cell can't survive. We are less than 90% similar to most other species. Even within the primate lineage, as compared to old world monkeys, protein coding sequences can vary by as much as 15% (be 85% similar). As you move further away to mice and flies and yeast, the percentage similarity falls off quite a bit.

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