Evolution through 21-year E. coli experiment

Sequencing genomes of various generations of the bacteria, which had been frozen periodically over the years, Lenski and his team found that adaptive and random genomic changes don't necessarily follow the same patterns. Rather than a plodding equilibrium, even in a consistent environment, the interplay between these two kinds of genomic changes "is complex and can be counterintuitive," Lenski said in a prepared statement.

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The new data "beautifully emphasize the succession of mutational events that allowed these organisms to climb toward higher and higher efficiency in their environment," Dominique Schneider of the Université Joseph Fourier in Grenoble, France, and a coauthor on the paper, said in a prepared statement.
ht*p://w*w.scientificamerican.com/blog/post.cfm?id=evolution-details-revealed-through-2009-10-18

Abstract

Genome evolution and adaptation in a long-term experiment with Escherichia coli

The relationship between rates of genomic evolution and organismal adaptation remains uncertain, despite considerable interest. The feasibility of obtaining genome sequences from experimentally evolving populations offers the opportunity to investigate this relationship with new precision. Here we sequence genomes sampled through 40,000 generations from a laboratory population of Escherichia coli. Although adaptation decelerated sharply, genomic evolution was nearly constant for 20,000 generations. Such clock-like regularity is usually viewed as the signature of neutral evolution, but several lines of evidence indicate that almost all of these mutations were beneficial. This same population later evolved an elevated mutation rate and accumulated hundreds of additional mutations dominated by a neutral signature. Thus, the coupling between genomic and adaptive evolution is complex and can be counterintuitive even in a constant environment. In particular, beneficial substitutions were surprisingly uniform over time, whereas neutral substitutions were highly variable.
ht*p://w*w.nature.com/nature/journal/vaop/ncurrent/full/nature08480.html

I read about this in "The Greatest Show on Earth", I found it really interesting and a powerful put down to the irreducible complexity argument.
On a side note the correspondence between Richard Lenski and Andy Schlafly of the Conservapedia. Is uber funny. I haven’t got time to summarise it now and its probably better that you read it in full.
Here is a good place to start its more about the second letter but it has links to what happened previously

Ok so I cant post links yet so just google “Lenski gives Conservapædia a lesson”

Lenski gives Conservapdia a lesson : Pharyngula

Lenski gives Conservapdia a lesson : Pharyngula

Richard Lenski has been growing cultures of Escherichia coli for 21 years representing about 40,000 generations. A new paper published in Nature provides details about genetic changes occurring during evolution, which can be divided into slow adaptive mutations and faster random changes.

Conservapedia? I always thought they were satire, like Landover Baptist.