Post Tagged with: "Richard Lenski"

Long-term Experiments

I recently read this Nature article, where is described what is probably one of the longest experiments ever to be conducted. A population of E. coli was kept for 20 years (!) in a nutrient solution (low on glucose), and samples were taken and deep-frozen after 2000, 5000, 10000, 15000, 20000 and 40000 generations. The authors sequenced the genome of the sample bacteria to investigate the rate of mutations.

Up to generation 20K, the number of mutations grew steadily to a total of 45. The adaptation to the environment, however, only increased strongly in the beginning. It was concluded that the most beneficial mutations were the first to occur. After generation 20K, a change in the mutT gene caused a rapid increase in the mutation rate to result in 653 mutation at generation 40K, but with a neutral signature, i.e. no further adaptation.

What I find most fascinating about this extreme long-term experiment is the confidence of the researchers that it would be possible to analyze the genes at a later point; this was not at all self-evident in the late ’80s! In addition, some work had to be done each day, for twenty years. What if the power had failed for a week or so? Of course, this unique opportunity to watch evolution as it happens is very intriguing.

An experiment that took even longer was awarded this year’s Ig Nobel Prize in medicine: Donald L. Unger of Thousand Oaks, CA, cracked the knuckles of his left hand, but not his right hand, every day for 50 years to see if knuckle-cracking leads to arthritis. After this time, both hands were fine, so he concluded: “While a larger group would be necessary to confirm this result, this preliminary investigation suggests a lack of correlation between knuckle cracking and the development of arthritis of the fingers.” Apparently, the experiment must be repeated.

By October 23, 2009 2 comments Uncategorized

Please hand me your final product

Science ethics is the new flavor of the past couple weeks around the chemical blogosphere (TCB, CB, TCB, SB) and continuing that trend is the story of Richard Lenski and conservapedia. Richard Lenski being the E. Coli evolving citrate consumption guy (pnas), was responding to which stipulations he would agree to before sending out samples of his evolved E. Coli to other scientists. The one thing that caught my eye was the following…

 

Richard E. Lenski 

Richard E. Lenski
Photo courtesy of Bruce Fox, MSU.

 

“I would also generally ask what the requesting scientist intends to do with our strains. Why? …I would not be happy to see our work “scooped” by another team”

The question is then what constitutes a fair request from a fellow scientist. PNAS terms state that the corresponding authors should “…allow others to replicate and build on work published in PNAS, authors must make materials, data, and associated protocols available to readers.” But one scientist’s fair use of materials could be considered “scoop” territory for an other. How many of you would readily hand over your precious final products for others to score papers on? In the end these types of things should be easily solved by having a healthy (even if bloated) author list.

If you do get scooped with your own work, and assuming your reputation is also somewhat high profile, no one will ever question your place in the field. More people will wonder about the voracity of the authors that set out to “scoop” you. There are enough other chemical questions out there.

To Lenski’s credit he does go on and say he would still provide samples even if it meant he would be scooped.

Mitch

Note 1 — More on the Lenski affair can be found here:
http://rationalwiki.com/wiki/Lenski_affair

Below the fold is the text from Richard E. Lenski’s 2nd letter to conservapedia (which is an awesome read): Click link below
Read more ›

By July 6, 2008 10 comments Uncategorized