Evolution can apparently be observed live in the act

Feb 28, 2014 10:36 GMT  ·  By

According to a presentation held on Wednesday, February 26, by esteemed Michigan State University (MSU) biologist Richard Lenski, it would appear that naturalist Charles Darwin was wrong on some aspects of evolution. The researcher was able to demonstrate that, in some instances, this process can be observed as it happens. 

One of the things Darwin argued in On the Origins of Species was that evolution is a very slow-going process that requires a lot of time to pass down even the slightest adaptations through generations.

In his experiments with Escherichia coli bacteria, Lenski determined that the evolution of new traits can be observed as it happens over decades, not centuries or millennia. The biologist has been running an experiment focused on the multiplication of E. coli cultures for the past 26 years.

One of the things that became abundantly clear in his work is that lab freezers can act like time machines, allowing researchers a glimpse into the process of evolution as it unfurls. Lenski said during his presentation that more than 59,000 generations of E. coli had lived and died in his cultures.

His Long-Term Experimental Evolution Project began in 1988. Since then, the dozen bacterial cultures he grows in parallel have doubled in size and are displaying a more rapid mutation rate than ever before. The microorganisms are also able to make better use of the glucose in their growth medium.

Interestingly, one of the 12 lines has evolved into what Lenski calls a new species, capable of consuming a derivative of citric acid, called citrate, which he drops in their growth medium. Usually, E. coli bacteria are unable to live off this nutrient, but this particular culture evolved the ability to do so.

The expert held its presentation, Time Travel in Experimental Evolution, at the Harvard University's Mineralogical and Geological Museum, during an event sponsored by the Harvard Museum of Natural History. Lenski said that the current generations of E. coli grow roughly 80 percent faster than the original cultures the experiment started with.

“I call this the experiment that keeps on giving, because the bacteria continue to do interesting things. I’d like this experiment to continue long after I’m gone,” the expert said. His is one of the few long-running bacterial experiments aimed specifically at catching evolution in the act.

Studies such as this may provide investigators with the clues they need to answer important questions about the origins of life on Earth, as well as about how complexity arose naturally out of simplicity. Such issues have plagued the field of evolutionary biology for centuries, but new answers could soon come within our grasp.