From Monash U: “New discovery challenges long-held evolutionary theory”

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Monash University

19 October 2017
Silvia Dropulich
T: +61 3 9902 4513
M: +61 (0) 0435138743
silvia.dropulich@monash.edu

1
Mike McDonald, a recent ARC Future Fellow with Laura Woods (left) and Aysha Sezmis (right).
Photo Credit: Steve Morton

Monash scientists involved in one of the world’s longest evolution experiments have debunked an established theory with a study that provides a ‘high-resolution’ view of the molecular details of adaptation.

Many of the challenges facing the world today are the result of evolutionary processes.

“Cancer is an evolving group of cells within your body, antibiotic resistance is the result of bacteria adapting to the use of antibiotics, and climate change is forcing whole ecosystems to adapt or die,” said study co-lead author Dr Mike McDonald, from the Monash School of Biological Sciences.

“A major goal of modern evolutionary biology is to be able to predict or anticipate evolutionary changes,” he said.

“Our study, published in Nature, provides a high-resolution view of the molecular details of adaptation over substantial evolutionary timescales.

“The insights we provide into the rate, repeatability, and molecular basis of adaptation will contribute to a better understanding of these evolutionary processes and challenges.”

Dr McDonald, a recent ARC Future Fellow, specialises in the genetics of adaptation. To explore this area Dr McDonald’s lab propagates populations of yeast and other microbes such as E.coli for thousands of generations in a variety of laboratory environments.

Dr McDonald has been involved in the ‘E.coli long-term evolution experiment’ – an ongoing experimental evolution study now in its 30th year led by Richard Lenksi. This study has been following the genetic changes in 12 initially identical E.coli populations.

“The Lenski study is the longest running microbial evolution experiment with more than 67,000 generations of E.coli, which is equivalent to over one million years of human evolution,” Dr McDonald said.

“In our study we found that even though the E. coli populations in our experiment have been evolving in a very simple environment for a long time, they are still adapting to their environment.

“In other words the fit get fitter.

“But the established theory tells us that adaptation should have stopped by now since there should be a ‘fitness peak’” that the E.coli should have reached by now – and our work shows that this is not the case.”

According to Dr McDonald, one explanation is that as E. coli evolve, they change the environment that they are growing in. This change to the environment then drives further evolution, so that the populations may never stop adapting.

In his study, researchers undertook genome sequencing which allowed them to track over 33,000 mutations for 61,000 generations of evolution, providing them resolution they needed.

“This also gave us a comprehensive view of how repeatable adaptation is, and how random effects can affect the outcomes of evolution,” Dr McDonald said.

See the full article here .

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Monash University (/ˈmɒnæʃ/) is an Australian public research university based in Melbourne, Australia. Founded in 1958, it is the second oldest university in the State of Victoria. Monash is a member of Australia’s Group of Eight and the ASAIHL, and is the only Australian member of the influential M8 Alliance of Academic Health Centers, Universities and National Academies. Monash is one of two Australian universities to be ranked in the The École des Mines de Paris (Mines ParisTech) ranking on the basis of the number of alumni listed among CEOs in the 500 largest worldwide companies.[6] Monash is in the top 20% in teaching, top 10% in international outlook, top 20% in industry income and top 10% in research in the world in 2016.[7]

Monash enrolls approximately 47,000 undergraduate and 20,000 graduate students,[8] It also has more applicants than any university in the state of Victoria.

Monash is home to major research facilities, including the Australian Synchrotron, the Monash Science Technology Research and Innovation Precinct (STRIP), the Australian Stem Cell Centre, 100 research centres[9] and 17 co-operative research centres. In 2011, its total revenue was over $2.1 billion, with external research income around $282 million.[10]

The university has a number of centres, five of which are in Victoria (Clayton, Caulfield, Berwick, Peninsula, and Parkville), one in Malaysia.[11] Monash also has a research and teaching centre in Prato, Italy,[12] a graduate research school in Mumbai, India[13] and a graduate school in Jiangsu Province, China.[14] Since December 2011, Monash has had a global alliance with the University of Warwick in the United Kingdom.[15] Monash University courses are also delivered at other locations, including South Africa.

The Clayton campus contains the Robert Blackwood Hall, named after the university’s founding Chancellor Sir Robert Blackwood and designed by Sir Roy Grounds.[16]

In 2014, the University ceded its Gippsland campus to Federation University.[17] On 7 March 2016, Monash announced that it would be closing the Berwick campus by 2018.