Where did the meat eating start?

University of Applied Sciences Bremen - University of Applied Sciences

Eating meat - since when and why?

Since when and why do we eat meat? A student contribution by Jesper Jordan and Thomas Werner Büdel. [10/19/2010] Meat Consumption Today Agricultural cattle breeding today causes around 40% more greenhouse gases than all vehicles in the world put together, making it the number one greenhouse gas emission (1). But is meat such an important source of nutrition that we cannot do without it?

Many studies with vegetarians show that not eating meat has any disadvantages. It is often argued that only meat contains all important proteins and vitamins that are easy for humans to use. But the so-called lacto-ovo-vegetarians, i.e. those who include eggs and milk in their diet, get all of these nutrients in sufficient quantities. Vegans, on the other hand, have to strictly ensure that they receive all the nutrients they need when they eat. On the other hand, many studies suggest that excessive meat consumption leads to an increased risk of heart attack, high blood pressure and high cholesterol levels. Type 2 diabetes, like colon cancer, is also associated with frequent meat consumption (URL1). Based on these findings, the question arises as to how meat consumption came about in the course of evolution.

Fig.1: Australopithecus - Characteristics: pronounced chewing muscles, broad, hard molars for chopping up tough plant food, crest as a base for chewing muscles, strong cheekbones, very large molars
Meat consumption from an evolutionary perspective (2) About 10 million years ago, the climate in East Africa changed from wet rainforest areas to dry savannahs. According to many researchers, these changes resulted in the splitting of the homonin populations into the great ape line and the human line. The upright gait probably already evolved in the rainforest, whose protection they now gradually had to leave and enter open landscapes.
While the Australopithecus was still a herbivore, which can be recognized, among other things, by a pronounced crest that served as the base of the muscles, the teeth and the skull without a crest of Homo ergaster suggest a diet with regular meat consumption. The beginning of meat-eating goes hand in hand with the development of tools by early humans about 2.5 million years ago.

Fig.2: Homo ergaster - lived on softer food with a high energy content, regular meat consumption, characteristics: no crest, less protruding cheekbones, smaller molars
It is not clear whether the early meat-eaters hunted their food or were scavengers. However, scientists believe that carrion was an important part of the diet. The "scavenger model" describes an early man who looked for suitable carcasses in riparian forest zones. The forest along the rivers offered adequate protection from other scavengers, such as vultures, which were arguably the greatest competitors for food.
The seasonal rhythm of the savannah meant that in the rainy season, not along the rivers as in the dry season, the carcasses were found in open habitats, where people were exposed to greater competition. The diet was therefore probably based on vegetable raw materials during the rainy season.

Fig. 3: Family tree hypothesis on human development

Compared to Paranthropus, the way of life of the genus Homo ultimately proved to be the more successful of the two genera that emerged from the delicate australopithecines. Members of the homo genus lived as generalists, allowing them to draw on the entire range of food, including meat-containing food. Paranthropus, on the other hand, was focused on plant-based food and thus a specialist, which ultimately led to the fact that it died out as a specialist about 1.2 million years ago due to the excessive competitive pressure.

The path of the genus Homo was by no means over here. On the contrary, once the upright gait was perfected, the brain began to develop and grow in size. The brain of Homo habilis measured 600 cm³ 2 million years ago, that of the early Homo ergaster measured 900 cm³ only 300,000 years later. Both types were generalists.

Anthropologists directly correlate the increase in brain mass with an improvement in diet and thus an improved supply of nutrients to the brain, which probably resulted in a synergistic effect. Growing food quality and brain growth caused a further increase in each other. Larger brains enabled more complex social behavior, which in turn improved food-gathering tactics. It should be noted, however, that the improved food quality could only have been one of several factors that led to an increase in brain mass. However, due to the increasing complexity of the brain, the first hunters and gatherers developed, the transition from scavengers to hunters. Homo erectus lived mainly on hunted game and collected fruits, which were shared among the members of the community, a behavior typical of hunters and gatherers, which further stabilized and improved the nutritional situation. The Neanderthals, which originated from Homo erectus, were exposed to a particularly difficult nutritional situation in the northern latitudes due to extreme cold. According to calculations, a Neanderthal man must have converted up to 4000 kilocalories during the Ice Age, which suggests his enormous abilities as a hunter.

In the course of evolution, humans succeeded better and better in optimizing their nutritional situation for them. So he began to breed animals and grow and conserve plants in large quantities. So meat consumption was an important part of human evolution. At that time, however, meat will have been far less available than it is today, and daily consumption of meat is therefore not part of human nature.
view Today convenience food, factory farming and genetically modified plants are a reality and just as normal. According to the FAO, global meat consumption will double to up to 465 million tons per year by 2050. In view of the fact that around 25,000 people die every day as a result of malnutrition and malnutrition and 852 million people worldwide suffer from hunger, the question arises whether such high meat consumption in industrialized countries can still be justified. There is hunger despite a global grain harvest of 1.57 billion tons, as almost half of the global grain harvest ends up in the troughs of the livestock. Furthermore, if all parameters are observed, 30,000 liters of water are required for one kilogram of meat, while around 50 liters are required for one kilogram of apples (URL 2). By avoiding or reducing meat and animal mass products, there would be no starvation in the world. A conscious and low-meat diet is therefore sustainable and future-oriented. References (1) FOER, J.S. (2010): Eating Animals. - 1st edition, Back Bay Books, New York, 352 pp.
(2) LEONARD, W. R. (2004): Spectrum of Science. - The evolution of humans II, Dossier 1/2004, Spektrum der Wissenschaft Verlagsgesellschaft mbH

URL 1: http://www.ncbi.nlm.nih.gov/pubmed/15702597?dopt=Abstract [10/18/2010]
URL 2: http://www.gesundzuhause.de/fileadmin/user_upload/pdf/Reduktion_des_Fleischkonsums.pdf [10/18/2010]

Image sources:
Fig.1: http://commons.wikimedia.org/wiki/File:Australopithecus_boisei_skull.jpg [10/19/2010]
Fig.2: http://commons.wikimedia.org/wiki/File:Homo_ergaster.jpg [10/19/2010]
Fig.3: http://de.wikipedia.org/wiki/Datei:Stammbaum_der_Ententwicklung_des_Menschen.png [10/19/2010]

Banner: http://commons.wikimedia.org/wiki/File:Human_evolution_scheme.svg