The Role of Pleiotropy in the Evolutionary Maintenance of Positive Niche Construction

Abstract

Organisms often modify their environments to their advantage through a process of niche construction. Environments that are improved through positive niche construction can be viewed as a public good. If free riders appear that do not contribute to the shared resource and therefore do not incur any associated costs, the constructed niche may become degraded, resulting in a tragedy of the commons and the extinction of niche constructors. Niche construction can persist if free riders are excluded, for example, if niche constructors monopolize the resource they produce to a sufficient degree. We suggest, however, that the problem of free riders remains because it is possible that nonniche constructors with an enhanced ability to access the resource appear and invade a population of constructors. Using mathematical models we show that positive niche construction can be maintained if it is inextricably linked to a mechanism that makes free riding costly, such as a trait that confers a benefit to only niche constructors. We discuss this finding in terms of genetic interactions and illustrate the principle with a two-locus model. We conclude that positive niche construction can both evolve and be maintained when it has other beneficial effects via pleiotropy. This situation may apply generally to the evolutionary maintenance of cooperation.

Implications of (co)evolution of agriculture and resource foraging for the maintenance of species diversity and community structure

“…From this equation, we immediately note that if we do not consider a direct benefit to niche construction ( e 1 ’(x mut )=0 ), the fitness gradient becomes negative (as s 1 ’(x mut )<0) : this leads to gradual decrease of the trait and counter-selection of niche construction. This is consistent with the result of Chisholm et al (2018): considering a direct benefit (from pleiotropy or pseudo-spatialization) is necessary to avoid a tragedy of the commons. That is inevitable given that our non spatial model implicitly assumes that all consumers have access to the farmed resource.…”

“…This latter could be considered a cheater in the evolution of cooperation terminology: it consumes the resource that is maintained by niche construction, without paying the cost of agriculture. Because of the direct benefit that the farmer obtains from the exploitation of the helped resource (“privatization” or “monopoly” (Krakauer, Page, and Erwin 2009; Chisholm et al 2018)), the invasion of the cheater is avoided and the two phenotypes coexist. The coexistence of cheaters and cooperators is a question that has been studied elsewhere in the context of social evolution.…”

“…Farming can then be considered a public good (Thutupalli et al 2017). Even if the threat of freerider invasion is overcome for instance through privatization (pleiotropy, (Chisholm et al 2018), monopolization of the niche (Krakauer, Page, and Erwin 2009)), trade-offs can still mitigate the evolution of agriculture by altering the profitabilities of the resources: if the cultivated resource is initially much less profitable than an alternative resource, we predict that agriculture may be counter-selected despite potential benefits. Behaviours associated with agriculture can be costly because of a high presence of competitors, predators or pathogens of the resource that needs to be actively protected (Stadler and Dixon 2005; Hübner and Völkl 1996; Adams et al 2013; Fernández-Marín et al 2013; Thutupalli et al 2017).…”

“…We also assume that niche construction provides a direct benefit for the organisms performing it: for instance, agriculture can provide a more direct access to the managed resource and increase its consumption efficiency, because of proximity, or another adaptation. This inclusion of a direct benefit (consumption efficiency is positively linked to the agricultural trait), has been shown to favor the evolution of niche construction (Chisholm et al 2018). In our case, we consider the simple formula where u<1 indicates saturating efficiency increase (diminishing returns, for instance if the efficiency consumption is constrained by other factors, such as physiological ones) while u>1 indicates an accelerating response.…”

Pleiotropy, cooperation, and the social evolution of genetic architecture

“…Both previous verbal arguments and our above results have focused on how pleiotropy can help stabilise cooperative traits that benefit other individuals [ 1 – 8 ] ( b > 0). However, our above analysis reveals that pleiotropy can also help favour traits that otherwise provide no benefits ( b = 0, c > 0) or even harm ( b < 0, c > 0) both their bearer and other individuals on the patch ( Fig 1 and S1 Fig ).…”