This is a first that what undermine certainties. In view of its diet, the man is not really what we can call a predator “superior”. It would be closer to the anchovies or pig that tiger or shark, reveals a team of French researchers from Ifremer, IRD and Agrocampus West, who has just published its work in the journal Proceedings of the National Academy of Sciences .
To get this unsettling conclusion, the scientists applied an index commonly used in ecology and applied to the majority of terrestrial and marine species but had never been calculated for man.
man just above the cow
This index, called “trophic level”, aggregates the data composing the diet of the species, and puts these on the food chain. To calculate the trophic level of the human species – Human trophic level (HTL) – The experts analyzed data from the organization of the UN Food and Agriculture Organization (FAO) collected between 1961 and 2009. Result: The man with the trophic level of 2.2, the one corresponding to herbivores. For example, the cow, which feeds exclusively on wild herbs, is situated at level 2. So far the orca, which, with the score of 5.5, dominates the food chain.
“The value of this index is very important because it helps to understand the relationships between species (predator-prey relationships, for example) and energy flow in ecosystems,” says Ifremer presentation his study.
From Burundi to Iceland
Pushing the analysis of HTL, scientists have also identified five major groups of countries based on their food consumption. It follows that if the Burundi and its diet consisting of 97% of plants reached the lowest trophic level of 2.04, Iceland (2.54) turns out to be the country most “carnivorous” planet . A qualification that is to its particularly high fish consumption.
addition to geographical comparison, the study reveals that the human trophic level increased by 3% over the past 50 years. “This increase shows that the human diet has a greater impact on its ecosystem (quantity and diversity of food consumed),” said Ifremer, which emphasizes the importance of continuing this study to “better understand the impact of our diet on our future to feed 9 billion people by 2050 capacity. “