Natures wonders: ants farm fungus for food (Introduction)

by David Turell , Wednesday, September 14, 2016, 22:55 (2990 days ago) @ David Turell

Another view of the same phenomenon:-https://www.washingtonpost.com/news/speaking-of-science/wp/2016/09/14/these-strange-subterranean-cities-are-eerily-like-our-own-but-theyre-ruled-by-ants/?wpisrc=nl_science&wpmm=1-"Between 55 and 60 million years ago, an ancient insect evolved the ability to feed a fungus and live off of its spores. Now there are some 250 ant species that farm fungi — tending to them, weeding them, ensuring that they have the nutrients they need. They depend on the fungus for food, and in turn, the fungus depends on the ants to grow.-***-"Ant colonies illustrate a phenomenon called emergence: Parts of a system acting in very simple ways can produce collective behaviors that are incredibly sophisticated, without anyone telling them how. The same phenomenon explains how individual birds can form a flock, and how the millions of neurons in our nervous systems can create consciousness. Many entomologists argue that social insects like ants should be studied on the scale of the colony, rather than the individual — it's by acting as a community that these creatures do what they do. (My bold)-"The original ant 130 million years ago was social," Schultz said, "and on that foundation of sociality all kinds of ant lineages have evolved very, very complicated behaviors."-***-"An agricultural ant colony begins with a single member, the queen. She seeds her garden with spores carried from her mother's home, and gives birth to the workers who will cultivate it. As the new colony grows, worker ants fertilize the fungus with bits of plant material collected from the outside — flower pollen, chewed up leaves. The most massive colonies can defoliate an entire tree in a matter of days, given the opportunity (though trees have evolved their own defenses).-"Some species have learned to "herd" aphid "cattle." The ants keep their bugs docile with tranquilizing chemicals the ants secrete from their feet (there are probably more than a few human cattle ranchers who wish they could do the same), then feed on the honeydew that the aphids excrete, much the way that humans drink cows' milk.-"Schultz and his colleagues have reconstructed the evolution of these abilities by comparing the genomes of more primitive species with those of advanced ones. DNA analysis of the ants' fungi shows that the crops' evolution mirrors that of the species that farms them. Many of the ant species have adaptations that make them better farmers, including crevasses on their bodies containing microbes that produce an antibiotic they can apply to their crops. Likewise, the fungi have evolved to become more appealing to their ants.-***-"As was the case with humans, insects became sedentary when they became farmers. Initially, farming wasn't as profitable as being a hunter-gatherer — both primitive ants and early subsistence farmers are thought to have been malnourished — but as agriculture became more advanced, it became more productive. These more sophisticated farms were able to sustain larger populations, which promoted division of labor, which gave rise to incredibly complex civilizations. -***-"Among both ant and human farming communities, all participants in the relationship have been irrevocably changed by it. Farming ants and their fungus have fundamentally different DNA than their non-farming relatives. Human farmers have evolved genetic adaptations that allow us to digest milk and metabolize fats; our crops, meanwhile, bear little resemblance to their wild ancestors.-"That said, ant farmers are not directly comparable to people. They're not consciously manipulating their fungi (indeed, Schultz said, you can imagine a scenario in which the fungi rule the relationship, bending millions of tiny ant servants to their will). Ant agriculture is a product of natural selection, of innumerable accumulated genetic accidents. New strategies aren't learned, they're evolved. But humans have consciousness and culture, and that allowed us to achieve in a few thousand years what took ants five hundred thousand centuries to accomplish. Even though ants have been farming for much longer, Peregrine said, there isn't much they can teach us about agriculture that we don't already know." (my bold)-Comment: Ants and fungi are an evolved, learned symbiotic relationship, but the key point is an integrated society acts like a giant single organism in ants and in humans with amazing productivity.. My bolded statements make the point. There is the usual vast difference in kind in how quickly humans learned agriculture compared to ants.