Eating: Evolution and eating introduction A2
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Evolutionary Explanations of Food Preferences Do we have an innate preference for certain foods? How were these preferences adaptive in the EEA? How do these preferences function now? 15/08/2022 Evolutionary Explanations 1
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Transcript of Eating: Evolution and eating introduction A2
10/04/2023 Evolutionary Explanations 1
Evolutionary Explanations of Food Preferences
Do we have an innate preference for certain foods?
How were these preferences adaptive in the EEA?
How do these preferences function now?
10/04/2023 Evolutionary Explanations 2
Background
• The environment of Evolutionary Adaption (EEA) is the environment in which a species first evolved
• Humans emerged 2 million years ago on the African Savannah
• Natural selection favoured traits which allowed survival in that environment
10/04/2023 Evolutionary Explanations 3
Evolutionary Explanations of Food Preferences
• Any current behaviours that appear to be maladaptive (dysfunctional) can often be explained as being functional in the past
• Our modern preference for calorific food can be traced back to our ancestors where it was adaptive
10/04/2023 Evolutionary Explanations 4
• Early humans were frugivores and relied on sweet fruits for their survival
• Harris (1987) – babies like sweet tastes
How are innate food preferences adaptive: Sweet
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How are innate food preferences adaptive: Salty
• In the hot African Savannah salty food would have been needed to replace salts lost through sweating
• Denton (1982) – animal research has shown innate preference for salty food
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How are innate food preferences adaptive: Umami
• Receding forests meant people had to start eating meat
• Inclusion of meat acted as a catalyst for brain growth
• Milton (2008) humans would never have evolved to become active, intelligent creatures without meat in their diet
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How are innate food preferences adaptive: Sour
• Discouraged people from eating foods that had gone off
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How are innate food preferences adaptive: Bitter
• Discouraged people from eating potentially poisonous food
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How are innate food preferences adaptive: Fatty
• Needed in EEA as high levels of energy needed to survive
• Burnham and Phelan (2000) preference for fatty foods come from times of food scarcity when this type of food is full of energy giving calories
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How are innate food preferences adaptive: Spicy
• Sherman and Hash (2001) – meat dishes contain far more spices than vegetable ones
• Spices have antimicrobial properties
• Could explain preferences for spices in hot countries
10/04/2023 Evolutionary Explanations 11
Food Neophobia
• Animals tend to avoid food they have not come across before
• Frost (2006) As a food becomes more familiar we show a greater liking of it
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Taste Aversion Learning
• Developed as a means of survival
• If we eat food that makes us sick it would be an advantage to avoid that food in the future
• Garcia et al (1955) rats made ill through radiation after eating saccharin developed an aversion to it
• Explains why food poisoning leads to inability to eat that food for a long time (association)
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Innate food preferences in the modern world
• Our food focus is no longer about eating enough to avoid malnutrition as it was in the past
• Our preference for sweet food can now lead to a highly calorific diet (chocolate, sugar)
• Our preference for salty food can now lead to a highly fatty diet (crisps, chips)
• • •
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Evaluation
• Good explanation of food preferences– i.e. good explanation of why we like foods
which have very little goodness
• Focus on ultimate rather than proximate causes– i.e. evolutionary approach considers
ultimate causes rather than looking at maladaptiveness (overeating)
– Genome Lag
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Evaluation
• Research– Difficult to falsify– However, we can study related species who face
similar adaptive problems to our ancestors– Fossils show the evolution of meat eating
• Suggests evolution has stopped though Wills (1999) say this is not the case
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IDA
• Reductionist
• Determinist
• Cultural Differences– Infant preferences of sweet food is universal– However, after infancy there is a broad range of likes
and dislikes– Evolved factors are modified by experiences made
available by our culture
• Supports Nature-Nurture debate
