The earliest farmers on Earth
Photos fossilized termite nests with remains of mushroom farms
Termites - ancient insects related to cockroaches. Unlike cockroaches, they are public lifestyle, build nests together caring for offspring and distribute responsibilities among family members. Social hierarchy and way of life of termites are the subject of scrutiny, and scientists were able to pick up another element of the puzzle. On-exposed cliffs rift basin undrained Lake Rukwa in south-western Tanzania, found the fossilized remains of nests built by termites 25 million years ago.
A detailed study of nests showed that close to a residential area in enclosed nest broken mushroom plantation fields confusing system, constructed in accordance with a complex plan. It is known that the culture of fungi can grow under these conditions only when the cultivation. This is now farming in the usual form, but only on the microscale.
Thus, termites grow your own food 25 million years ago, long before the appearance of humans. Researchers estimate that it is the oldest evidence of agriculture on the planet. Perhaps it is termites belong to the invention of agriculture, rather than men.
comparing ancient fossils thermite farms with termite nests modern era
The found fossils allow scientists to more accurately date the development of an evolutionary symbiosis between termites and fungi. According to new estimates, this symbiosis began about 31 million years ago, says Eric Roberts (Eric Roberts), a geologist at the Australian James Cook University, lead author of the research.
Virtually the whole of Africa is widely known for massive, edible "termite mushrooms" which grow for themselves tiny insects. But scientists until the mid-20th century did not understand the true value of these facilities and what is actually happening in the termite colonies.
When biologists were cut and carefully examined termite mounds (termites), sometimes as high as a growing person, they found dozens of mutually united chambers, built specifically for the cultivation of mushrooms.
It turned out that termites form obligate symbiotic relationship with this particular type of fungus that is, they can not live without each other. Termites prozhёvyvayut indigestible plant material and the form of his tiny pellets - milosfery who sowed tiny fungal spores. When the mushrooms grow, working terms produce the harvest, and then the entire colony eats it. During the same time the growth of fungi is digested before inedible plant material, making it edible. According to experts, this way the termites recycle up to 90% of dry wood in the semi-arid savannah ecosystems, which makes termites landshaftopreobrazuyuschey powerful force.
Previous studies on the molecular biology of mitochondrial DNA led to speculation about the origin of such obligate symbiotic relationship with fungi termite approximately 25-30 million years ago. But until now, there was no physical evidence that agriculture in termites appeared in the time period. The oldest fossilized termite mounds dated to the Late Miocene, ie 7-10 million years ago.
To obtain such evidence, important for evolutionary history, it has been awarded a grant from the National Science Foundation to carry out an international expedition to Lake Rukwa the famous rift - a large linear cavity in the earth's crust, which was formed at the break the crust as a result of its extension or longitudinal motion
Location Great Rift Valley
In ancient basin of Lake Rukwa Tanzania biologists have found fossils of thermite structures built millions of years ago. Among them were two thermite farm. Very well-preserved nests once inhabited by termites. Each of the nests houses several cameras the size of a tennis ball, and in them - the fossilized fungi and granules of plant material - milosfer, which were used for cultivation of mushrooms. In the surrounding rocks, scientists have identified during construction of thermite farms:. 25 million years
structure and composition of the surviving milosfer
Scientists believe that through farming termites were able to survive and thrive in a rapidly changing environment. The ecosystem has been transformed from the lush rainforests to arid semi-desert, but because of fungus termites successfully converted timber dried food for themselves.
Becoming farmers, termites were much better adapted for life in all conditions, which contributed to its rapid spread across the continent.
By the way, the termites were not the only creatures who practiced agriculture and breeding of fungi plantations for wood processing. We did the same leaf-cutting ants in the Americas. They are about 10 million years ago, began to grow in anthills mushrooms Leucocoprinus of family Agaricaceae, soiling their milosferami of cut worker ants leaf chewed mass (update from muravevoda ants genus Atta cultivated fungi of the genus Leucoagaricus (leucoagaricus), ants genus Acromyrmex - mushrooms Leucocoprinus (belonavozniki )).
Scientists also suspect that is about the same millions of years ago have begun to do beetles, ambrosia beetle, which bear the sporangia spores storage drevorazrushayuschih symbiotic fungi.
Studying farms termites age 25 million years shows that the cultivation of food social insects has evolutionary advantages - it allows to survive in difficult environmental conditions, and to establish a colony in virtually any climate. Termites have occupied all the continents on the planet, except Antarctica.
Approximately 24,988,000 years after the termite people also opened this winning strategy.
Scientific work published June 22, 2016 in the journal PLOS One (doi: 10.1371 / journal.pone.0156847).