Evol Ecol Res 20: 365-383 (2019)     Full PDF if your library subscribes.

Genetic bandwagoning: natural selection for quality-dependent altruism

Idan S. Solon

Greenlawn, New York, USA

Correspondence: I.S. Solon, Greenlawn, New York 11740, USA. email: IdanSolon@gmail.com

ABSTRACT

Background: In separate literatures, biologists have marshalled theoretical and empirical support for theories that a variant (i.e. allele, epigenetic mark, or combination thereof) can be selected to (1) induce suicide by a moribund or otherwise stressed individual, (2) induce suicide by an individual with low productive or reproductive potential, (3) impose senescence upon a chronologically old individual, and (4) reduce the yield of an individual with low genetic heterozygosity. High stress, moribundity, low productive and reproductive potential, high chronological age, and low genetic heterozygosity all indicate an individual with low genetic quality — that is, comparatively few advantageous genetic variants for acquiring prey, territory, or mates, or surviving predators and parasites. Therefore, an unappreciated commonality between these theories is that a variant can be selected that actually reduces the fitness of an individual of low genetic quality.

Bandwagoning: The fitness losses induced by the variant in low quality individuals allow fitness gains for nearby individuals, some of which hold a copy of the variant. The heritable elements (alleles, epigenetic marks, etc.) within a single individual which can lead to such losses are collectively termed a ‘bandwagoning variant’ because the variant gains frequency by hitch hiking along with (‘jumping on the bandwagon’ of) higher quality individuals (and their lineages) that have copies of it.

Question: What parameter values (e.g. population size, relatedness, heritability of reproductive success) might allow natural selection for genetic bandwagoning?

Features of the model:: The model is an individual-based Moran process. Each individual’s quality value is randomly chosen at birth from a normal distribution that has a mean equal to the quality value of its parent.

Ranges of parameters: N (the total number of individuals in the population) varied from 50 to 500. Assortment ('relatedness’) in the population varied from 0.05 to 0.15. Recorded values for the heritability of reproductive success varied from 0.024 to 0.132.

Conclusions: A variant can be selected to respond to various indications that the individual holding it has low genetic quality by inducing that individual to further reduce its fitness by forfeiting some or all of the resources (e.g. food, territory, mates) it could otherwise have used. Natural selection for genetic bandwagoning can occur even when values for N, relatedness, and heritability of reproductive success are low enough to be in line with reported values for humans and other species. Therefore, genetic bandwagoning theory might explain why indications of an organism’s low genetic quality induce behaviour by that organism, or biological processes within it, that reduce that organism’s fitness.

Keywords: programmed ageing, heterosis, depression, Hankshaw effect, evolution of cooperation, acceleration of adaptive evolution.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2019 Yi Ta Shao. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.