Scientists have found the final missing link answering a long-standing question about how social behaviour evolves. New research shows that a social supergene in fire ants coordinates a host of biological processes and behaviours, that ultimately determine how sociable their colonies are, and who they choose to be their queen.
Have you ever had the “what would win in a fight” conversation with various different insect and arachnid combinations? Cockroach vs Mantis, Spider vs Scorpion, Ant vs Spider? Well, if you can think of it, nature has probably done it. True to form, I present you: Ant vs Spider, a battle being played out in Australian forests as we speak.
As we are very rapidly discovering, living creatures have the ability to drastically alter the climate and weather systems on Earth, and the greatest changes are achieved by the species that are greatest in number. Ants may be no exception to this rule, and recent geological research suggests that ants may be providing a vital counter-balance to our CO2 emitting ways. Ants may be cooling the climate as we warm it. But are ants the solution to climate change?
Ants and Climate Change
A recent study published in Geology has begun to reveal the role ants play in keeping Earth’s atmosphere cool. They might be small, but ants are ubiquitous on Earth, found on every continent except Antarctica and numbering over 15,000 species. They have the potential to have a big impact. The study published this month showed that ants collect minerals from their environment and change them into rock, inadvertently trapping carbon dioxide gas in the rock as they do so. This process is identical to the way in which atmospheric CO2 is sequestered by the oceans, and naturally weathered on land.
Social insects show extraordinarily high levels of cooperation, giving up their reproductive opportunities and even sacrificing their own lives to save the colony. The social insect colony is a well-oiled machine, each part has its own key role to play, together forming an intelligent and adaptive society. Most people are familiar with the highly advanced social insects, such as honeybees and leaf cutter ants. Their societies are huge and intricate, and we have gained many fascinating insights from them. However, they tell us very little about how these societies evolved, or what it meant to be cooperative in a more primitive sense.
Crime and Punishment
Ant societies are remarkably complex and ants exhibit extremely high levels of cooperation. Workers will often sacrifice their own lives to defend the safety of the nest. However, just like human societies, ant nests are also rife with conflict. Where there is cooperation there will always be individuals who try to take advantage and cheat the system.
The defining characteristic of ant colonies (and social insects in general) is reproductive division of labour, where reproduction is dominated by one or a few individuals, known as queens. In this matriarchal system, reproduction is forbidden for most colony members, and in many ant species worker ants are physically incapable of mating. Despite being unable to mate, due to their unusual genetic system, ant workers can still lay male eggs. This gives them the opportunity to try and cheat the system, and in many ant species workers have been found to illicitly try and lay eggs, when the queen isn’t looking. Such crimes do not go unpunished, however, and in many species the honest workers will punish cheaters, either through physical aggression, or by destroying the illegally laid eggs.
They might seem simple and insignificant, but like humans, ants have discovered the benefits, and costs of agriculture. In the ant world there are species which farm livestock, protecting them from predators and milking them for rich nectar, and others which cultivate tiny underground fields of fungus, pruning it and using chemicals to prevent disease and pests.
Crops and Livestock
Humans developed farming around 10,000 years ago, but the ants have been at it much longer. In its simplest form, ant farming consists of simply pruning the surrounding forest. Ants of one species found in the Amazonian rainforest have been found to remove unwanted plant species when they appear in its foraging area. Although simple, this ‘weeding’ behaviour can be devastating, with ants clearing huge sections of forest of any species which is not beneficial to them.
You might not think you have much in common with the small, six-legged creatures that occasionally break into your home to raid jam jars, but over the next three articles I hope to illuminate some of the parallels between people and ants. Like humans, ants are highly social; building civilisations, utilising sophisticated mechanisms of communication, and nurturing other living creatures in various forms of agriculture. And just like us, their societies are sometimes compromised by cheats and criminals. Ants share many of these traits with other members of the social hymenoptera, which includes most bees and wasps. Few species outside this group have developed cooperation as sophisticated or complex.
It is well known that ants are exceptionally strong and fast. Although estimates vary, the average ant can carry between 10 and 50 times its own body weight, and run at approximately 300 meters an hour, a rate of nearly 800 times its body length a minute. This is equivalent to the average western man carrying between 850 and 4500kg (4.5 tonnes) over his head, and running at a speed of 83km or 52 miles per hour. If ants can do it, why can’t we?
The calculation above is essentially redundant, because a human-sized ant wouldn’t be able to travel at 50 miles an hour, in fact it wouldn’t be able to run at all; its legs would crumble under the weight of its own body. In fact, the human-sized ant would have been dead long before it tried to run, because the supply of oxygen to its organs wouldn’t have been sufficient to keep it alive, even for a second.