>They take these antibiotics from the metapleural gland
The fact that a gland could arise through natural selection makes over 112 different components from anti-biotics to chemicals blows my mind.
The underlying theory that "random mutation" and errors in the copying of ant DNA created a secretion sac is crazy to me. I imagine this first ant was like the "Mule" in foundation, where he could introduce chemicals to "Control and conquer". There seems to be some underlying learning mechanism built within "Random mutation".
Heck yeah, evolution is mind-blowing sometimes. Ok, most of the time. However, as a layperson, I often find that things aren't so random and almost unbelievable as they seem at first glance when you start having more context and pieces to fit together.
It appears that we have long known that ants, like humans, have microbiomes that produce myriad antimicrobial and antibiotic compounds (and other bioactive molecules) which they are able to make use of. [1] In this paper it sounds like there are other glands that also store and secrete these antimicrobial compounds.
So both mechanisms -- antimicrobial compounds from the microbiome and storage/secretion in glands -- most likely existed prior to the development of this specialized metapleural gland. This specific gland is used very frequently in grooming behavior. When they groom themselves, each other, the queen and larva (and even their fungal colonies in the case of leafcutters), they may massage their metaleural gland prior to this grooming to apply antimicrobials/antibiotics and reduce risk of infection. Presumably grooming behavior existed prior to this gland as well, and almost certainly involved secretions from other glands (saliva or the ant equivalent comes to mind), especially to 'clean off' old pheromones as well as crud that would interrupt signaling.
So we have pretty much all the ingredients independently for this rather specialized organ + behavior (*this is a narrative constructed via layperson reading and speculation, not in any way intended to be presented as scientific fact).
Also, I'm no biologist (let alone evolution/genetics specialist), but what I understand and what makes the most sense to me is that evolution is no longer strictly believed to occur solely on the basis of random mutations. For instance, we have a lot of evidence in very specific cases that epigenetic changes can occur in response to the environment as well as internal processes, and that these changes can be inherited and become a permanent part of the genome by various proposed mechanisms:
>There is now good evidence that epigenetic inheritance is ubiquitous and is involved in adaptive evolution and macroevolution. I argue that the many evolutionary consequences of epigenetic inheritance open up new research areas and require the extension of the evolutionary synthesis beyond the current neo-Darwinian model.
The abstract of another paper goes into more detail on how epigenetics may directly and indirectly influence evolution, if you are interested. It's mostly over my head beyond the broad strokes. [3]
The fact that a gland could arise through natural selection makes over 112 different components from anti-biotics to chemicals blows my mind.
The underlying theory that "random mutation" and errors in the copying of ant DNA created a secretion sac is crazy to me. I imagine this first ant was like the "Mule" in foundation, where he could introduce chemicals to "Control and conquer". There seems to be some underlying learning mechanism built within "Random mutation".