Sunday, October 31, 2010

What do I want in a genetics textbook?

I'm trying to complete a questionnaire about a genetics textbook (for its publisher), but it's hard because my objections to it (and all the other genetics texts on the market) are so cosmic in scale.  I started trying to write a few paragraphs that summarize what I think is wrong and what should be done.  But now I think I should write a more substantial article, that I would submit to Genetics or to Nature Reviews Genetics.  Below are some sentences:

Genetics textbooks teach students to manipulate meaningless symbols and numbers according to what appear to them to be an arbitrary set of rules.

It's pure wishful thinking to believe that most students in an introductory genetics course can come to understand how inheritance works by walking in the footsteps of Mendel and Morgan.

Nor will they learn how genes affect phenotypes by following genetic symbols through crosses that obey apparently arbitrary rules.

Nor does the ability to manipulate genetic symbols according to a set of rules show that they understand anything about how inheritance works or genes affect phenotypes.

Nor des the ability to apply technical terms to pattern-recognition images show that they understand anything about what meiosis accomplishes or how it does it.

The ability to put genotype symbols into a Punnett square doesn't mean students understand meiosis and mating.

The ability to decide whether to use an uppercase or lower case letter for an allele doesn't mean students understand anything about how allele combinations determine phenotypes.

Students naturally (wisely) treat meiosis as a pattern-recognition challenge, and think dominance is an intrinsic property of certain alleles, perhaps caused by some mysterious kind of epigenetic modification.

Wednesday, October 20, 2010

If evolution is wrong...

I'm working on a one-page handout to be given out at an upcoming talk by a young-Earth creationist.    I think I've discovered a new slant on the 'why evolution must be true' arguments:

Evolution is as true as gravity:
Not only is evolution fully consistent with the other principles of science, if it were false they would also have to be false. 
If evolution is wrong:
·  Probability must be wrong.  If weak effects of genetic differences don’t accumulate over many generations, we must not understand the cumulative effects of recurring rare events.
·  Geology must be wrong.  If we don’t know how to date fossils, we must also not know how to date rocks.
·  Biochemistry must be wrong.  If biochemical pathways didn’t evolve, then metabolism makes no sense.
·  Microbiology must be wrong.  If viruses don’t evolve, we shouldn’t keep getting colds and the flu.
·  Genetics must be wrong.  If natural selection doesn’t happen, mutant genes must not be passed on to offspring.
·  Physics must be wrong.  If evolution hasn’t happened, we must not understand the laws of thermodynamics.
·  Pharmacology must be wrong.  If lab animals aren’t our relatives, our drug tests must be giving the wrong results.
·  Ecology must be wrong.  If we don’t know how species change, we must also not know how species interact with their environments.
·  Agriculture must be wrong.  If the plants and animals we eat didn't evolve by natural selection, we couldn't have improved them by artificial selection.

With young college students (my target audience) I think this may be quite a powerful argument for evolution.  Basically, if they believe that scientific research has gotten evolution all wrong, they have to also suspect all the other parts of science and technology that their lives depend on.

But I don't think I've done a very good job with the particulars.  I find it hard to twist my mind around the consequences of discarding things I'm confident are true, and I'd welcome any suggestions for improvement.

Here's the second part of the handout:

Evolution is as important as life:
As individuals and societies, we are now making decisions that will have profound consequences for future generations.
·  How should we balance the need to preserve the Earth’s plants, animals, and natural environment against other pressing concerns?
·  Can we preserve endangered species without changing them?
·  Should we alter our use of fossil fuels and other natural resources to enhance the well-being of our descendants?
·  To what extent should we use our new understanding of genes to alter the characteristics of living things?
·  How can we prevent bacteria from becoming resistant to our antibiotics?
Unless we understand evolution we will not be able to make these decisions wisely.

I think this is also not very well done.  I lifted most of it from the conclusions of the National Academy of Sciences 88-page report on Science, Evolution and Creationism.  If this doesn't get rewritten I'd better remember to credit them in a footnote. 

Thursday, October 07, 2010

Don's brilliant idea

I was just meeting with some genetics textbook editors and the colleague that I'll be teaching the new genetics course with.  I had been saying that I want to include a writing component in the assignments, and he had described an essay assignment he had used with an advanced class.

Later we were griping about the quality of news reporting of genetics issues, and he had the brilliant idea of requiring each student to write a 'letter to the editor' correcting some incorrect genetics information  that they had read in a newspaper, magazine or blog, or heard or seen in a broadcast.  Each student would be expected to find their own information to correct.  We could incorporate peer review, so the authors would have to revise and improve their draft letters.  The TAs would mark the letters, and the students would be strongly encouraged to then send them to the offending writer or editor.

What a blast!  Hundreds of letters sent, complaining about specific errors in science journalism.