Tag Archives: Adaptive Path

Ann Gauger’s new peer-reviewed paper on Darwinian evolution

Amazing new research paper by the Biologic Institute. The PDF of the paper, “Reductive Evolution Can Prevent Populations from Taking Simple Adaptive Paths to High Fitness,” is available here.

The MP3 file is here.

Participants

  • Jay Richards, Director of Research at the CRSC, (Discovery Institute)
  • Ann Gauger, senior research scientist at the Biologic Institute

About Ann:

Ann is a senior research scientist at Biologic Institute. Her work uses molecular genetics and genomic engineering to study the origin, organization and operation of metabolic pathways. She received a BS in biology from MIT, and a PhD in developmental biology from the University of Washington, where she studied cell adhesion molecules involved in Drosophila embryogenesis. As a post-doctoral fellow at Harvard she cloned and characterized the Drosophila kinesin light chain. Her research has been published in Nature, Development, and the Journal of Biological Chemistry.

Topics:

  • Co-authored with microbiologist Ralph Seelke at the University of Wisconsion
  • Purpose: study whether bacteria can evolve the ability to fix a broken protein (e.g. – enzyme)
  • Two areas are broken in the enzyme
  • If you fix the first one, it works a little but not fully (slight advantage)
  • If you fix the second one, it starts to work fully (huge advantage)
  • It’s a “two-step adaptive path” – a textbook case for evolution
  • should be able to hit both mutations and get back full functionality
  • At the start of the experiment, the cell is churning out broken protein
  • there is a cost to the cell for create the broken protein
  • the cell can either go through the adaptive path and repair the protein
  • OR, it can shut off production of the broken protein
  • EITHER PATH gives a selective advantage
  • So what happens? The cells NEVER followed the adaptive path
  • They almost ALWAYS turn off the production of the broken protein
  • It happens in 30-50 generations, in 14 different cultures
  • Each culture had a different way of turning off the production
  • They tested on 10^12 cells
  • Only one cell made the first repair, none made the second repair
  • It’s more advantageous to STOP PRODUCING the broken protein as soon as possible
  • The first cell that gets rid of the non-functional protein first overtakes the whole culture
  • so, even adaptive paths that provide a benefit with one mutation are unlikely to be followed
  • The point: even promising theoretical adaptive pathways MAY NOT WORK in experiments

I wrote about Doug Axe’s recent research paper here. He is the Director of the Biologic Institute.

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