I may have mentioned this before but it begs reiteration. We are not the experts in our fields! We’ll at least I’m not. I’m continually reminded of this and it depresses, as well as inspires me. Depresses me because I feel incompetent.



I’m suppossed to know – I’m an AP Biology teacher!

I want to know – I’m a ‘scientist’!



But the truth is, I’m not a scientist. I’m not in the trenches day after day. My knowledge of statistics is abhorent. Coupled with the fact that textbooks take years to publish. Here’s the story that led me to this:



A few days ago I ran accross an article I needed to see back in November [when it was published]. Titled Theme: Three Domain Hypothesis, Larry Moran over at Sandwalk wrote an excellent article describing inaccuracies portrayed about a commonly accepted theory [at the high school science level]. I teach this theory! Larry makes the point that the evidence doesn’t substantiate the theory in its entirety.



I hope I write this accurately.



The theory tends to portray the three domains of life: bacteria, archea and eukarya as having evolved from a common ancestral cell. This cell forms the ‘trunk’ of the tree of life from which the three distinct domains derive. This theory originally used evidence from ribosomal ribonucleic acids. It seems it was quickly adopted and entered the textbooks. Of course many high school science teachers have been out of school for quite awhile and rely upon texts to be accurate.

It seems a larger proportion of evidence suggests a great deal of horizontal gene transfer occurred between a community of early cells that evolved simultaneously in early earth ecosystems – rather than one cell type. Also, the differences between bacteria and archea are no larger than within each domain. This suggests the bacteria and archea domains are not very distinct  and hence are hard to substantiate as seperate domains.



So whats my point?



For one, the internet, blogging and wikis, have allowed me to be cognizant of this inaccuracy and modify my teaching. We teach our students to diversify their reliance on sources. So to do we as teachers. The net has made this far easier.

Secondly, many teachable moments have derived from this. Science as a process or the nature of science is  at play here and provides me with a  great opportunity to highlight this to my students.



I want to thank real scientists like Larry Moran, PZ Myers and the other university professors – the real scientists – for blogging and making my job more interesting and accurate.



Linzel





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