Research happiness

A while ago I posted a bit about my research woes.  Well, I’m happy to report that my efforts since then have been fruitful.  Creating the new constructs seem to have done the trick.  There must have been something wrong with the original recombinant plasmid I was using (one that I didn’t actually create myself, by the way).

I’d never thought I would be so happy about seeing a little purple band appear on a little peice of paper before, but that band indicates the right protein is getting expressed and I can see it via western blot.

Posted in microbiology, my research | No Comments »

DaveScot on Lenksi

DaveScot, an IDiologist who writes for the uncommondescent blog has claimed to have found a mistake in Richard Lenski’s paper. (which I first talked about here)

He points to a statement made by Lenski: (DaveScot’s emphasis)

However, selection requires heritable variation
generated by random mutation, and even beneficial mutations
may be lost by random drift.

And then points to a study done by the Scripps institute that would seem to contradict this statement:

The bold portion is patently wrong. Selection operates on any heritable variation whether random or not… The Scripps researchers, in a nutshell, discovered that E. coli, when stressed (such as running out of food as in Lenski’s experiment or in the presence of antibiotics in the Scripps experiment) selectively increases the mutation rate on certain genes.

What DaveScot has wrong (and I believe he was refering to this experiment) is that the study says that mutations are purposefully induced on specific genes.  However, the doesn’t say that only beneficial mutations are induced or that mutations were localized only to specific genes.  This is a case of an organism increasing the rate of random mutations, which is a good survival strategy for a population to increase its genetic diversity.  However, it does not appear to be the case, that the bacteria is select for their own survival.

So DaveScot is wrong in saying:

Thus the mutations in this case are not random but rather directed at a certain area in an attempt to solve a certain problem.

There is no basis to this teleological statement.  Bacteria aren’t attempting to solve a problem, not in the same humans do when we create a new medicine or drug.  They are simply increasing their genetic diversity (and probably not on purpose either, more likely in response to selection pressures), so that when antibiotics are around, the probability of a random mutation conferring antibiotic resistance is increased.

DaveScot FAIL

Posted in creationism, evolution, genetics, link out, microbiology | 9 Comments »

Richard Lenski responds

Thanks to bascule at SFN for this link.

Richard Lenski, whose groundbreaking work witnessed the evolution of citrate-using E. coli in a mere 44,000 generations over 20 years of work.

He responds directly to conservapedia’s ignorant creationism populace published by conservapedia (amazingly enough) here:

Lenski’s second letter is particularly good, filled with lots of good biochemistry, scientific philosophy and general good sense. A highly recommended read.

Discuss the exchange here.

Posted in biochemistry, creationism, evolution, link out, microbiology | 3 Comments »