check
Nonlinear Physics Seminar: "Effect of non-demographic noise on stochastic population dynamics" | The Racah Institute of Physics

Nonlinear Physics Seminar: "Effect of non-demographic noise on stochastic population dynamics"

Date: 
Wed, 06/12/201712:00-13:30
Location: 
Danciger B building, Seminar room
Lecturer: Shay Be'er
Abstract:
In this talk I will discuss the effect of different types of non-demographic noise - noise emanating, e.g., from environmental variability - on the long-time dynamics of stochastic populations.
I will first discuss the role of time-fluctuating reaction rates in genetic switches. I will show how this type of noise can strongly decrease the stability of phenotypic states leading to a heterogeneous cell population, and why this may be beneficial when the population of cells is under stress.
Second, I will discuss a different type of non-demographic noise in the form of uncertainty in the reaction step-size. That is, given the usual reaction scheme mA -> kA, we allow, e.g., the product number k to be a-priori unknown and sampled from a given distribution. By doing so we demonstrate that this type of noise can also have a dramatic effect on the long-time stability of stochastic populations, in the form of greatly increasing the population's stability compared to the case of fixed k.
All our results are tested against numerical Monte-Carlo simulations, and we argue that the evolutionary adaptation of various populations to time-varying environments is strongly influenced by both types of non-demographic noise.