Food Acquisition and Selection

Generalists such as humans and rats find food sources by foraging and deciding how long to stay with specific sources (as studied in the foraging literature preference) and choose specific foods to eat based on evolved preferences, especially for sweetness and texture, and develop learning abilities, including social mimicry and learning about taste aversion.

The cultural evolution of using a variety of staple foods such as corn, dairy, and meat in various cuisines has given rise to several genetically programmed human predispositions, including a preference for fat and sweet. The underlying emotion of disgust was initially associated with the food system, but through pre-cultural adaptation, it entered many other areas of human life.

Food Selection in Humans

People worldwide spend more money on food than on anything else. People in Western countries such as Germany and the United States spend 21 percent of their income on food, second only to leisure activities. Food consumes over half of all revenue in less-developed nations such as India and China. On the other hand, food takes center stage in parent-infant relationships worldwide.

Nothing is more vital for survival early in life than determining what should be consumed or avoided. Humans have evolved defense systems against natural poisons. Terrible-smelling and bitter-tasting substances, for example, are not random. Gagging, spitting, and vomiting are all reactions meant to keep us from consuming hazardous substances or to get rid of those that get past our taste and smell defenses.

It is not by luck that many youngsters detest veggies like broccoli and Brussels sprouts. These vegetables contain the chemical allyl isothiocyanate, which is hazardous to youngsters.

Disgust is a proposed adaptation that acts as a defense against microbial assault, protecting individuals from sickness. One cross-cultural research asked Americans and Japanese to rank the most repulsive items. Feces and other bodily wastes were cited the most, accounting for 25% of the written comments. Feces, in particular, are known to hold toxic substances such as parasites and poisons, making them especially hazardous to people.

After all, feces are what the body excretes. Additional poll responses included inadequate hygiene (potential disease transmission route), bodily boundary breaches such as a gaping wound, nasty sex, and death. Humans acquired an aversion to specific groups of things that threatened their survival, such as excrement and other disease conduits. According to this adaptationist theory, the disgust reflex safeguards the body from consuming or coming into touch with chemicals that might harm human health and survival.

Adaptation to Food Scarcity

Many species of wild animals and our human ancestors evolved in environments with infrequent food sources, so they often spent long or more days without food. Thus, natural selection has favored individuals who can outperform their competitors cognitively and physically when in food shortages. A wide range of cognitive abilities in the animal kingdom - spatial navigation, decision-making, sociability, and creativity - are primarily concerned with the acquisition and reproduction of food.

Foraging success is closely related to reproductive success, a topic discussed elsewhere and not discussed further here. From a bioenergetics perspective, a broadly conserved adaptation to food scarcity is the metabolic switch from liver-derived glucose utilization to a ketogenic state, in which nerve and muscle cells use fatty acids and ketones derived from fat cells as cellular fuel for cognitive support performance and physical endurance, respectively.

Food Acquisition in Humans

Until agriculture developed about 10,000 years ago, all humans lived by hunting, gathering, and fishing. As agriculture emerged, nomadic hunter-gatherers were gradually pushed out of the main arable land and eventually confined to the forests of the Amazon, the arid grasslands of Africa, and the remote islands in remote areas in Southeast Asia and the Arctic tundra. Today, only a few scattered tribes of hunter-gatherers remain on the planet. Food of animal origin (ASF) has always been a part of the human diet.

However, the mode of their use has changed dramatically throughout human evolution. Before 2 million years ago, meat was acquired randomly through hunting small or young animals and picking up carcasses of animals killed by other species. After this time, humans began to cooperate in hunting, purchasing large game meat possible.

  • Meat

  • Agriculture

  • Cooking

The domestication of cattle helped provide humans with a steady supply of meat and other animal products such as milk, wool, and hides. The ability to cook and prepare food allowed Homo erectus, Neanderthals, and Homo sapiens to take evolutionary leaps that distinguish them from chimpanzees and other primates.

Preparing food with utensils and fire means more calories can be consumed, and less time is needed to forage and eat. Molecular size decreases while body mass increases. Among primates, larger animals have larger molars and spend more time eating – similar-sized great apes spend about 48% of their day consuming calories.

The stove may have come from other African species and appeared just before Homo erectus, including Homo habilis and Homo rudolfensis. Agriculture has played an essential role in the rise and fall of civilizations. Ancient civilizations thrived along rivers and deltas thanks to fertile soil and adequate water. A typical diet in early societies was the high consumption of grains, nuts, and seeds with little meat. The ancient Harappans of the Indus Valley cultivated legumes while cereals were their leading food besides consuming many fruits and vegetables.

Typical protein sources in the ancestral diet include legumes, whole grains, and occasional animal protein, although the wealthy could afford more. These diets are nutritionally complete because combining grains and legumes has added amino acid profile requirements. Most nuts, seeds, and grains are higher in methionine and cysteine (sulfur-containing essential amino acids) but lower in lysine (essential amino acids). On the other hand, most lentils and legumes are higher in lysine but lower in sulfur amino acids.

Early hominids forage in closed rainforest habitats, presumably feeding mainly on fruit and leaves. Early hominids migrated from this environment to the savanna and expanded much of their food stock. They will use their taste buds to identify nutritious foods. The risks of poor food choices when foraging lead to wasted energy and metabolic damage from consuming foods low in nutrients and energy and toxins that can be harmful to the body and potentially fatal. The learned consequences of foods ingested can then guide our future food choices. The evolved human ability to taste is still helpful to billions of people living with very low food insecurity by helping them identify nutrients.

Changes in Diet

Necessary dietary changes, including the initiation of meat consumption, cooking, and related changes, characterize the evolutionary history of hominids to the domestication of plants and animals. Decades of anthropological research have been devoted to unraveling this dietary history, partly because these alterations may be associated with significant anatomical and cultural changes (e.g., increased relative brain size and the birth of modern civilization through agriculture). However, this reconstruction is also essential for understanding the evolutionary context of our modern diets and the diseases commonly associated with them.

Along with reconstructing the dietary history of hominins, molecular evolutionary analyzes were used to interrogate the genome for signals of genetic adaptation to other diets together. Early hominids moved from forest habitats to savanna habitats (where openness and tall grass were probably responsible for the possible advantages of selecting bipeds), accompanied by transitioning to more complex and familiar food in new environments.

Why Humans Like Spices: The Antimicrobial Hypothesis

Humans must eat, yet eating carries risks to their life. Taking objects from outside the body and eating them allows hazardous microorganisms and poisons that can cause disease or death to enter the body. These dangers are present in practically everything we consume, and most of us have felt "sick to my stomach" or vomited due to "food poisoning." Several of these threats can be reduced in today's world. However, consider our forefathers' period, before refrigerators and artificial preservatives, when food was scarce, and sanitation standards were naturally lower.

Cooking, which destroys most microbes, is one apparent answer. Cooking, which involves the regulated use of fire, has been around for at least a third of a million years and may have been around for as long as 1.6 million years. Spices might also be used as a remedy. Spices are derived from plants, including flowers, roots, seeds, bushes, and fruits. Spices have distinct aromas and flavors due to molecules known as "secondary compounds." Plants often use these compounds to keep macroorganisms (herbivores or plant-eating animals) and microorganisms (pathogens) at bay.

According to the antimicrobial hypothesis, spices kill or hinder the development of microorganisms and prevent the generation of toxins in the foods we eat, assisting humans in solving a fundamental survival problem: avoiding being ill or poisoned by the foods we eat. Several sources of evidence support this idea. Secondly, all thirty species for which we have robust data killed several of the food-borne bacteria species on which they were tested. Could you guess which spices are the most effective in killing bacteria? Onion, garlic, allspice, and oregano are among them. All four spices were effective against every bacterial species tested in the lab.


Dietary transitions to carnivores and cooking were crucial events in human evolutionary history that dramatically changed our biology and culture. Evidence for these behaviors in the fossil and archaeological records is scarce. As our ancestors ate more meat, the impact of this dietary transition could be significant. Some researchers speculate that eating more meat may have expanded the human brain, improved cooperation and communication, and advanced in-stone tool technology.

Updated on: 11-Apr-2023


Kickstart Your Career

Get certified by completing the course

Get Started