Abstract
I use an individual‐based model to investigate the evolution of cell division rates in asexual populations under chronic environmental enrichment. I show that maintaining increased growth rates over hundreds of generations following environmental improvement can be limited by increases in cellular damage associated with more rapid reproduction. In the absence of further evolution to either increase damage tolerance or decrease the cost of repair or rate of damage, environmental improvement does not reliably lead to long‐term increases in reproductive rate in microbes. Here, more rapid cell division rates also increases damage, leading to selection for damage avoidance or repair, and a subsequent decrease in population growth, which I call Prodigal Son dynamics, because the consequences of ‘living fast’ force a return to ancestral growth rates. Understanding the conditions under which environmental enrichment is expected to sustainably increase cell division rates is important in applications that require rapid cell division (e.g. biofuel reactors) or seek to avoid the emergence of rapid cell division rates (controlling biofouling).
Highlights
The tradeoff between producing high quality offspring and many offspring is well studied, and provides a general explanation for why the optimal rate of offspring production is often below the maximum possible rate (Flatt and Heyland 2011)
CO2 enrichment often occurs in the absence of environmental deterioration, and, in cases where fertilizer or other nutrient-rich runoff is present in aquatic systems, CO2 enrichment can occur alongside other types of nutrient enrichment (Boyd and Hutchins 2012; Snell Rood et al, 2015)
I first show that damage can limit growth rate evolution under environmental improvement, demonstrating Prodigal Son dynamics in the absence of evolution in damage and repair strategies over a range of values of Δt and α
Summary
The tradeoff between producing high quality offspring and many offspring is well studied, and provides a general explanation for why the optimal rate of offspring production is often below the maximum possible rate (Flatt and Heyland 2011). Ostreococcus sp., on the other hand, have a plastic response to CO2 enrichment where cell division rates increase, but lineages often reverse this response after hundreds of generations in a high CO2 environment (Schaum and Collins 2014) (Figure 1, scenario C).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
