Meet Solenopsis geminata - tropical fire ant, a hot climate specialist found in hot arid regions around the world. It has spread globally through human commerce and is a major invasive pest in many regions, busily destroying biodiversity values on the way. Loves disturbed areas - a dead cert for a starring role as climate, population and food production find their convergent crises, I'd wager.
Now meet Pogonomyrex sp., a Genus of harvester ants from the deserts of northern and southern America. (Sadly no recent photos from Alex Wild this time, just the unattributed portrait from Wiki). Echoing Chandler in the sitcom "Friends" the connection between these two screams "Big Head, Big Head"! Fortunately a trio of scientists delved further, measuing the head size and shape of both polymorphic and monomorphic species. (Ed: Forget the Australian island "World's best job", surely being an Ant Measurer is a contender for the title?). Anyway, they detected signs that the polymorphic forms were a response to dietary change, and concluded that bimodal shape variation may be a common evolutionary response to seed processing.
The sting in the tail from this train of thought? What adaptations to specialised roles and tasks might serve our descendents if they need a different societal model to survive - assuming we are reconnected to forces of natural selection or technology allows us to create our own castes? Or will the big brains in our own big heads get us out of this mess first? (Ed again: my female descendents are O.K. with this, just so long as one caste all look like Hugh Jackman).