How the geometry of ancient habitats may have influenced human brain evolution
Here is an article in Ars Technica where the author postulates that landscapes that are not too dense and not too sparse comprise a “Goldilocks zone” where evolution could maximize cognitive abilities.
In an earlier paper in 2017 the author, Malcom MacIver:
…and several colleagues published a paper advancing an unusual hypothesis: those ancient creatures who first crawled out of the water onto land may have done so because they figured out there was an “informational benefit” from seeing through air, as opposed to water. Eyes can see much farther in air, and that increased visual range could lead them to food sources near the shore. MacIver and his primary co-author, paleontologist Lars Schmitz of the Claremont Colleges, argued that this in turn drove the evolutionary selection of rudimentary limbs, enabling the first animals to move from the water onto land.
Recently, MacIver has theorized an even more provocative hypothesis: the geometry of certain habitats shapes evolutionary selection pressures in predator-prey contexts. Dense habitats like rain forests or jungles maximize hiding in cover while wide-open plains maximize speed to escape. Using a complexity measure, they show both of these habitats have low complexity. The article states:

The complexity “sweet spot,” according to MacIver, is a landscape like the one featured in The Hobbit chase scene, or like Botswana’s Okavango Delta, both of which feature an open grassland and moss zones dotted with clumps of trees and similar foliage. “In this zone, neither speed games nor running for cover maximizes survival rate,” said MacIver. “But planning—by which I mean imagining future paths and picking the best based on what you think your adversary will do—gives you a considerable advantage.” And that planning requires the kind of advanced neural circuitry typical of the human brain.
They built predator/prey simulations to test survival rates of the prey under two different strategies. The first was habit-based, akin to entering a memorized password when prompted; the second was plan-based, involving the ability to imagine several scenarios and select the one with the best chance for survival. They used a simple landscape with no visual barriers to simulate a water environment and added various objects, with varying density distributions, to simulate land. The patchy landscape in the Goldilocks zone of complexity showed a huge increase in survival rates for prey that relied on the planning strategy, compared to the habit-based approach. They even developed an online game to illustrate how different landscapes (coral reef, jungle, savanna, and open water) affect our ability to plan and evade a stalking predator. You can play it here https://maciver-lab.github.io/plangame/
The upshot is his hypothesis that the patchy landscape in the Goldilocks zone of complexity relates to the near-quadrupling in brain size that occurred in hominids after diverging from chimps. Which leads him to say:
More speculatively, MacIver thinks this could prove relevant to the question of why human beings struggle so much with thinking about looming existential threats, particular those in the distant future—climate change, for instance, or antibiotic resistant bacteria (or a global pandemic). “Inasmuch as you believe that the ability to think about the future was driven by a need to plan, and that our ability to think about the past is derivative of this need, a lot of who we are may hinge on why we evolved the circuitry to plan in the first place,” he said. “The reason we are so bad about planning for the distant future may redound to limitations in this circuitry that we have not yet developed the cultural technology to circumvent.”

In other words, he is saying our ability to “plan our next move” is limited to short-term gains, i.e. escaping the predator, not long term gains like foreseeing the severe consequences of human’s cumulative effect on the planet’s ecosystem. Our brains have evolved to escape the near term threats but can’t seem to handle the longer term threats that loom in the future. So we have examples of slash-and-burn agriculture where humans deplete the sustaining capacity of a soil only to move on to the next area: but they can’t imagine running out of “the next area” to move to. Or strip mining mineral resources and leaving a barren moon-scape useless to any future human use.
In the July issue of National Geographic a villager in the upper reaches of the Indus River lamented his village was facing a water crisis from climate change caused by the actions of economies far removed from the simple farming and herding of his village. Would anyone care?
But there are also counter-examples to the examples of despair. In the US laws have been passed that require the reclamation of mined land. Germany, once largely dependent on coal, is moving beyond it . With increased efficiency of sustainably farmed lands, advocates hold that sustainably farmed lands may be as productive as conventionally farmed ones.
The April 2020 issue of National Geographic was a split issue with half discussing “How We Lost the Planet” and the other half “How We Saved the World” with evidence for each discussed in this issue. As Susan Goldberg, editor-in-chief wrote in the lead editorial:
It’s a fitting reminder this month as we mark the 50th anniversary of Earth Day. For the occasion, we’ve created the first ever “flip” issue of National Geographic—essentially two magazines in one—to revisit environmental milestones of the past half century and to look ahead at the world our descendants will inhabit in 2070, on Earth Day’s 100th anniversary.
Two scenarios emerge.
On the magazine cover, there’s a verdant Earth. Welcome to the optimistic view of writer Emma Marris, who sees a world that is changed—we cannot undo some damage we have done—but one in which technologies will be harnessed to “feed a larger population, provide energy for all, begin to reverse climate change, and prevent most extinctions,” Marris writes. “The public desire for action is bursting forth on the streets … Just as in 1970, the electric crackle of cultural change is once again in the air. I believe we will build a good 2070.”
Elizabeth Kolbert looks to a new normal of “sunny-day flooding,” when high tide will send water gushing across low-lying U.S. coastal cities, and most atolls will be uninhabitable. This is the world of longer droughts, deadlier heat waves, fiercer storms, and more. “I could go on and on listing the dangerous impacts of climate change,” Kolbert writes, “but then you might stop reading.” She sees no evidence that we will address those and other threats fast enough to keep them from overwhelming us and the natural world.
It’s impossible to know who is right. The stories in this issue reflect divergent realities. When I read about the young people taking charge of the environmental movement, I feel buoyed. Then I see Pete Muller’s photos of a scarred landscape we will never get back. What I do know is that it is our job to provide a factual framework for what is happening, documentary photography about what is forever changed and what we can save, and information to help empower all of us to make a difference.
Goldberg is correct, it’s impossible to know who is right. Can we as a species evolve beyond the short term goal seeking to find the combination of thinking that will avoid the doomsday scenario? Can enough of us reach that evolved threshold to make the difference necessary to achieve a sustainable future?
What say you?
I say we’d better.









On Thursday I found out that a prior co-worker had just passed away from a heart attack. He was only 45. He used to sit in the cubicle next to mine and helped be out a lot when I was first diagnosed with type 1 diabetes. He had been diagnosed as a child. It hit home. Donovan was passionate about racing his motorbikes and I always appreciated his sense of humour.























