Now that summer has come and gone, I find that I spend the majority of my "free time" preparing lessons for my Advanced Placement Biology courses. You'd think that a guy with a B.S. in Ecology and Evolution, a Masters in Biology, and eighteen years of teaching experience would breeze through his lessons each day... nothing could be further from the truth. The A.P. Bio curriculum is so comprehensive, that I need to spend many hours a week studying, preparing and rewriting lessons. Sure I've taught this class for more than a decade, but look how much biology has changed in that time.
Our knowledge of genes and genetics have been transformed as we've learned more about the genetic code. When I began my formal studies of biology in the 1980's, we described genes as discrete units that coded for specific proteins. We believed that humans were so complex, we assumed that our genome would be twice as large as a mouse. While we didn't know much about the mouse genome, scientists' believed that humans must have at least one-hundred thousand genes... this seemed like a big enough number. Biologist understood that genes had to be regulated... turned on and turned off, be we were clueless about the mechanism.Fast-forward thirty years... today we discuss the key regulatory sites on what were once called non-coding sequences of DNA, we've learned that epigenetics can result in short term inheritance of characteristics, and we now know that humans probably have fewer than thirty-thousand genes.
So what does all of this have to do with Kenya, Birds, and dinosaurs? Well having spent this weekend with my nose in books, thinking about metabolism, enzymes, and DNA, I couldn't help but recall a college lecture delivered by a stodgy old professor. We were studying patterns in evolution and comparative physiology when this prof said, "and you know, the dinosaurs didn't go extinct... today, we call them birds." This was the first time I heard the hypothesis and saw the anatomical evidence that changed the way I understood the connectedness between all living organisms on this planet. So, as I think about teaching my students about our current understanding of DNA and how it demonstrates the way life is intimately linked through billions of years of evolution, I offer you the opportunity to think about prehistoric times and the dinosaurs of our day.
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