The consumption of insects is a possible solution to world hunger and the shortage of meat that will occur in the middle of the 21st century, as the WHO and FAO themselves have recognized on some occasions.
Although there are many skeptics who refuse to consume these animals, there is also a wide public that is increasingly attracted to this custom. The truth is that it is not such a strange or innovative behavior, because as a new study carried out by the University of California points out, it is a habit that we have inherited from our ancestors.
The research has been based on an analysis of the genome of some 107 different species of mammals . The results reveal that our most distant ancestors, creatures that inhabited the planet more than 60 million years ago, fed on bugs. This finding has been possible because the genes for the enzymes that allowed the predecessors of all mammals to eat insects are still present in almost all modern mammalian genomes.
In fact, scientists assure that this evidence is present in animals (through the non-functional pieces of these genes on their chromosomes) that do not follow this type of diet, as is the case of tigers or seals.
“One of the best things is that you choose the animal you choose, including humans, they have remains in their genomes from a time when mammals were small, probably insectivorous and running when dinosaurs still roamed the Earth,” says one of the principal investigators of the project, Christopher Emerling . “It is a signature in your genome that says that a long time ago you were not the dominant group of organisms on Earth. By looking at our genomes, we look at this ancient past and a lifestyle that we didn’t even get to live with. “
The genetic evidence complements the conclusions drawn years ago by paleontologists by analyzing the fossil remains and tooth pieces of the first mammals. Theoretically, it was in the wake of the disappearance of these large carnivorous and herbivorous reptiles that mammals began to change their diets.
An advance in evolution and in health
Different bacteria have genes that produce an enzyme that breaks down the outer shells of insects and that are made up of a strong carbohydrate called chitin. The enzyme in question is called chitanase .
The researchers found that the higher the percentage of insects in an animal’s diet, the more chitinase genes were found. So it is possible to trace this enzyme in humans. Emerling’s team also showed that these genetic remains are not unique to humans or primates , but can even be observed in ancestral placental mammals.
The finding could shed light on other roles played by these enzymes, as they are not only found in the intestine, but also in the salivary glands, pancreas and lungs, where they may be involved in asthma . Emerling says that knowing more about chitanase will be able to answer multiple questions about the evolution and physiology of mammals adapted to their diets.
Reference: Christopher A. Emerling, Frédéric Delsuc and Michael W. Nachman. “Chitinase genes (CHIAs) provide genomic footprints of a post-Cretaceous dietary radiation in placental mammals” (2018) Science Advances. DOI: 10.1126 / sciadv.aar6478
