Morning sickness that occurs in the majority of women in the early stages of pregnancy has been explained through Profet’s (92) embryo protection hypothesis. Buss (08) found that the foods that are most frequently avoided during pregnancy are coffee, tea, meat alcohol, eggs and vegetables. As all of these things can potentially damage a developing foetus’ organs or contain toxins it is believe that morning sickness acts as a deterrent from consuming and digesting these foods. Therefore morning sickness would be a useful adaptive quality, as it would prevent things that could potentially prevent a person’s genes being passed on to the next generation. This is supported by the idea that morning sickness is arguably the most severe during early pregnancy, which is the time in which the foetus is most vulnerable.
Food Neophobia explains that the preference to avoid novel foods is thought to be a product of evolution as avoiding new foods would safe guard people from unknown toxins. People are extremely responsive to aversion learning, so that they can be conditioned to avoid foods with only limited negative experience with them. This would therefore be an adaptive quality, as gradual conditioning would result in a person being exposed to further toxins.
Finally, it has been demonstrated that humans have an efficient regulatory system that promotes a balanced diet. This might suggest that the human body has evolved the capacity to recognise what nutrients are requires for optimal functioning, which would make our food preferences the result of evolution.
The evolutionary explanations of food preference are arguably reductionist. It overlooks other factors by focussing exclusively on our food preferences being the product of millions of years of evolution. Therefore the evolutionary explanations of food preference might be regarded as an oversimplification. For instance, a child’s food preference can be dictated through what their mother ate during her pregnancy. Julie Mennella studying taste in infants at the Monell Chemical Senses Center stated, “ Things like vanilla, carrot, garlic, anise, mint — these are some of the flavors that have been shown to be transmitted to amniotic fluid or mother's milk.” Research ahs been carried out by the Monell Chemical Senses Center on this idea. The infant participants were given carrot juice flavour cereal. The cereal was eaten and well received by those participants whose mother drank carrot juice during pregnancy. Participants whose mother had not drunk carrot juice did not like the cereal at all. This could indicate that if a mother ate sugary foods during pregnancy this could explain a baby’s preference for sweat foods, instead of evolution being the cause. This would support the idea that the evolutionary explanation of food preferences is reductionist. In addition, going by the evolutionary explanation of Gustation and olfaction, people should not like sour foods, yet sour sweets are sold and bought in supermarkets across the world. In addition to this, considering Buse (08) states incidentally almost every type of food is avoided during pregnancy as they can potentially “harm” the child, you would therefore expect any pregnant mother who eats, to get morning sickness, but not ever mother does experience it.
However, there are studies that are said support the evolutionary explanation of food preference. Yet such studies support the fact that humans have these food preferences and that is therefore taken to be support for the evolutionary explanation. Yet it could be argued that they don’t actually support that these food preferences we have developed through evolution. That is the problem with evolutionary explanations as they are incredibly speculative which makes it hard to support through research. Yet, the fact that obesity levels are rising and that more people than ever overeat may make evolutionary sense. It was thought by Steven and Price (2000) that the obesity problems encountered by most of the western world are testament to an inability to escape this evolutionary pressure (to have a preference for salty, sweet and fatty foods). This is supported by the fact that it would take us thousands of years to evolve out of a food preference that was once an adaptive advantage but is no longer one in today’s society- evident by the fact this preference is causing people to be overweight.
Some of the evolutionary explanations of food preference appear to completely be on the nurture side of the nature vs. nurture debate. For instance, aversion learning can only happen after an individual has had a negative reaction to a food, which would make it reliant on life experience and therefore nurture based. Yet on the other hand, morning sickness is heavily nature based. The process of the body regurgitating food that could hurt the foetus is clearly to with inside a person’s body and their biology. However, when it comes to gustation and olfaction, it could be either nature or nurture. Having taste receptors on human tongues is clearly down to a person’s biology yet, the process of evolution allowing individuals to recognise which taste corresponds to highly calorific foods would be reliant on the life experience of eating different foods. Therefore it would be both nature based and nurture based.