Turtle ant soldiers scuttle to and from sporting shiny, adorably oversized heads, which they use to block the entrances of their nests — essentially acting as living doors.
Not all heads are shaped alike: some soldiers have ones that resemble manhole covers and perfectly seal tunnel entrances. Others have square heads, which they assemble into multi-member blockades reminiscent of a Spartan army’s overlapping shields. TheThe shape and size of a turtle-ant soldier’s head is dictated by the type of tunnel the species in question occupies. The ants don’t dig the tunnels themselves, but move into those excavated by wood-boring beetles. And since a hand-me-down tunnel might be too big or too small, Kronauer says, the ants diversify rapidly to be able to occupy it.
To examine the evolutionary journey of various head shapes, the researchers grouped 89 species of turtle ants based on whether soldiers sported a square, dome, disc, or dish-shaped head. They also included a group of turtle-ant species that don’t have soldiers. They then examined the evolutionary relationships among these groups using the species’ genetic information, which they had previously gathered.
If evolution was a one-way path, the first turtle ants that appeared some 45 million years ago should have lacked soldiers altogether, then gradually evolved toward specialization — starting with the generalist, square-headed soldiers, all the way to those with highly-tailored dish heads.
But the new analysis suggests that this was not the case. Instead, the oldest common ancestor the researchers could trace likely had a square head. That ancestor went on to form a range of species, from ones with no soldiers at all to others with different levels of specialization. In some cases, more specialist species reversed direction over time, evolving back into more generalist head shapes. (1)
But you cannot adapt!
Unless you have already done so…
At the end, even the trees will die.
And your big question will be answered.
And as you leave your last breath.
Right next to some dead ants running.
A smile will spread across your face.
I will never change!
I have adapted!
I will not live for ever!