Do humans forage optimally and what does this mean for zoology on the table?

Abstract

Optimal Foraging Theory (OFT), enables understanding of foraging behaviour, which is exhibited by all of life, through the assumption that foraging behaviour maximises some currency of foraging. OFT has been relatively successful for nectar-feeding animals, with energy the primary foraging currency, and less successful for generalist herbivores and omnivores, for which foraging currencies include nutrients. It has been extended to other areas of biology, applied to human foraging, is a strong ecological theory, and 2016 marks its' 50th birthday. Human foraging has been affected by interrelated , recent and rapid developments of agriculture, animal husbandry, technology, social living and culture. Consequently, the foraging environment in which humans evolved is long gone, and our foraging may not be well adapted to current circumstances. Human foraging is therefore caught in "evolutionary traps". For example, as generalist omnivores we evolved a 'balanced diet', commonly represented by 'food pyramids', reflecting how often we encountered and consumed various food types during our evolutionary past. We therefore evolved preferences to collect and consume foods high in fats, oils, sugar and salt, valuable when rare, but adversely affecting our health with increasing availability. Additionally, given diverse arrays of potential food items, we should mimic foraging behaviour of others, especially those we know, admire and trust. Consequently, we are strongly affected by cultural influences, and by advertising and marketing of food types and 'fad diets', especially when promoted by movie stars, sports heroes and the like. Being omnivores, animal meat will likely remain 'on the table' indefinitely, with consumption depending on availability, plus benefits and costs, whether real or imaginary, all ingredients of the optimal foraging approach. Of course, perceived benefits of consuming animal meat are likely to be greatly influenced through what we hear or see via others. Looking ahead, 'zoology on the table' will remain contentious, OFT will be significantly developed for non-human organisms with some interest in understanding human foraging, and there will be much further research on effectiveness of advertising. No doubt, we shall continue to be deluged with messages advocating what we should eat and drink, and health issues associated with non-optimal diets will persist.

Evaluating the human capacity of carrying loads without costs: A scoping review of the Free‐Ride phenomenon

“…Thus, it may be argued that transporting edible loads is not a strong selective pressure to reduce the energetic cost of burden transport (Pulliam, 1974). On the contrary, and following the premise that efficiency should always be promoted (Bettinger et al, 2015; Binford, 2001; Codding et al, 2011; Hill et al, 1987; Kaplan & Hill, 1992; Pulliam, 1974; Pyke, 2017), we propose that the selection pressure to develop certain efficiency in load transport arises when the loads transported do not represent a direct energetic benefit for the carrier, as is the case of carrying dependent children, transporting raw materials, carrying to provisioning others, and so forth.…”

El coste de la supervivencia en las poblaciones humanas del Pleistoceno

“…Diversos trabajos han mostrado que los comportamientos o estrategias de forrajeo en las comunidades cazadoras y recolectoras se basan en criterios de optimización que varían en función de factores como el riesgo, la predictibilidad de los recursos, o la disponibilidad de nutrientes, entre otros (Bettinger, Garvey, y Tushingham, 2015;Codding, Bird, y Bird, 2011;Hill et al, 1987;Kaplan, Hill, y Hill, 2017;Pyke, 2017). Pero de entre todos estos factores, el principal determinante de las estrategias de optimización en los viajes de forrajeo es el nivel de disponibilidad o escasez de recursos.…”

“…Hay muchos factores que afectan a la eficiencia de forrajeo de un organismo y sería determinista y alejado de la realidad considerar que la optimización de la energía o del tiempo son los únicos criterios que rigen las decisiones de forrajeo o la aptitud biológica de una especie, como ya se ha señalado en investigaciones previas (Bliege- Bird et al, 2001;Binford, 2001;Codding et al, 2011;Foley, 2005;Kaplan et al, 2000;Pyke, 2017). Factores como los riesgos de depredación o la estacionalidad afectan también a la toma de decisiones durante las expediciones de búsqueda y aprovisionamiento de alimentos (Houston y McNamara, 1985).…”

“…En estos casos, el criterio de optimización suele ser tanto el tiempo como la energía (Bliege- Bird et al, 2001;Winterhalder, 1981). Sin embargo, estos criterios de optimización pueden cambiar dependiendo de factores como el tamaño del grupo (Binford, 2001), la estacionalidad (Foley, 2005;Kaplan et al, 2000), el riesgo de depredación (Bliege- Bird et al, 2001), o la disponibilidad de nutrientes (Pyke, 2017). De entre todos estos factores, el principal es la disponibilidad de recursos.…”