What would you do for greater good? – Ant Disinfection

jepper(55)

Published in

#steemstem

Words

329

Reading

2 min

Listen

Play

Hi guys! Today I would like to talk about small, yet not microscopic, astonishing creatures – Ants. They are called social insects, meaning that they cohabitate in colonies and basically act together as one organism. As they live in these crowded societies they are expected to experience a greater risk of disease outbreak. However, the incidence of these outbreaks is not higher in ants. How is that possible?

Source

Individual < Collective

Ants developed a collective disease defence termed social immunity. As their colonies behave like one big “superorganism” they are required to cooperate in order to prevent the disease from spreading. In this concept there is no room for individuality in contrast to other social organisms, such as mice or humans. Since evolution favours the survival of the colony over its members, selection has resulted in a plethora of cooperative and altruistic traits that ants perform to protect the colony from harm. This means that the priority of each member of ant community is to benefit the community as whole.

Typical ant colony is comprised of a queen and her daughters – workers. These workers fulfil broad range of various assignments. One of these assignments is sanitary care. This involves grooming and use of antimicrobial secretions that reduce the likelihood of pathogen exposure and development of infection. Normally protection and care for individual is beneficial for the colony as well, but in the case of contagious disease this is different, because the infected individual poses as direct threat for the survival of all. Thus, social immunity is characterized by a care-kill dichotomy, meaning that colony members should be cared for when possible, but sacrificed if necessary. Both outcomes benefit the colony.

Source

However, there is a different question in play. What happens when this sanitary care fails, and a pathogen successfully infects a colony member, thus rapidly increasing the risk of an epidemic. This question was the central point of recent article from Christopher Pull published a week ago.

In his research, Pull et al. infected the brood (baby ants really) of the invasive garden ant with a common soil fungus. What they observed was something drastic. When the ants discovered the infection, they unpacked the pupae from cocoon and bite them. In the next step ants sprayed bitten pupae with antiseptic poison – successfully killing the pupae along with the fungus…

Even though this may seem little over the board it is in fact necessary for sufficient protection of the whole colony. Actually, this so called destructive disinfection has many parallels with vertebrae immunity system, where the safety and integrity of whole organism is above the fitness of individual cells. These findings and similarities suggest that for both the evolution of multicellular organisms as well as from single animals to superorganisms the ability to detect and destroy threats is necessary.

Luckily, we are no ants, because then the world would probably be much colder place. On the other hand, maybe then there would be rapid decrease in disease spread and benefits in other rergions of life. One can only wonder, but hopefully we will never find out.

Have a great day!