Physics 434, 2015: Project 1, Luria-Delbruck, Revisited

Back to the main Teaching page.

Back to Physics 434, 2015: Physical Biology.

Let's figure out if the selection on standing variation is a good model of the Luria-Delbruck experiment. Specifically, download the Luria-Delbruck data (experiments 22-23) from the textbook web site. Construct three models of these data: the Lamarckian model, the Darwinian model, and the combination, where there's a probability of both the Darwinian natural variation and the Lamarckian induction of new mutations by the stress. Fit all three models to the data, and use Bayesian model selection to decide which of the three models produces the best fit.

Read up on things like mutation hotspots (I am deliberately not giving you any references -- find them yourself), and see how else you can modify the model. Build such a more complex model and again compare it to the simpler ones to see which one explains the data the best. Was the Luria-Delbruck interpretation of their data correct? (For this, you need to read their original paper so that you know what their interpretation was).

Notice that this is an open-ended problem, and I don't know the answer myself.