Month: August 2018

Enlarge / The 3.32 million-year-old foot from an Australopithecus afarensis toddler from different angles on the left, next to the fossil remains of an adult Australopithecus foot on the right. Credit: Jeremy DeSilva & Cody Prang (credit: Jeremy DeSilva and Cody Prang)

Early hominins' four smaller toes had adapted to bipedal walking by around 4.4 million years ago, but the big toe remained better-suited to grasping and climbing for a few million more years, until some time early in the evolution of our genus, Homo. That’s the conclusion of a new study by Stony Brook University anthropologist Peter Fernandez and his colleagues, who studied the size and shape of the metatarsals (the bones of the mid-foot) in modern humans, fossil hominins, and an assortment of monkeys and apes.

Spring in our step

Primate feet evolved mostly to grasp while climbing, which is why chimpanzees have more flexible feet than humans and why their big toes are opposable, like our thumbs. Humans—and our hominin predecessors—are the weird exceptions in the primate family tree, with the basic architecture of our feet adapted to bear weight while walking.

Some of those adaptations, like the one Fernandez and his colleagues studied, look pretty subtle to anyone who is not a specialist in primate foot anatomy. Their study focused on how much the head of the metatarsal protrudes toward the top of the foot, sticking out above the shaft of the bone like a dome, at the joint with the phalanx (one of the bones that makes up the toes) at the base of the toe.

Enlarge / The 3.32 million-year-old foot from an Australopithecus afarensis toddler from different angles on the left, next to the fossil remains of an adult Australopithecus foot on the right. Credit: Jeremy DeSilva & Cody Prang (credit: Jeremy DeSilva and Cody Prang)

Early hominins' four smaller toes had adapted to bipedal walking by around 4.4 million years ago, but the big toe remained better-suited to grasping and climbing for a few million more years, until some time early in the evolution of our genus, Homo. That’s the conclusion of a new study by Stony Brook University anthropologist Peter Fernandez and his colleagues, who studied the size and shape of the metatarsals (the bones of the mid-foot) in modern humans, fossil hominins, and an assortment of monkeys and apes.

Spring in our step

Primate feet evolved mostly to grasp while climbing, which is why chimpanzees have more flexible feet than humans and why their big toes are opposable, like our thumbs. Humans—and our hominin predecessors—are the weird exceptions in the primate family tree, with the basic architecture of our feet adapted to bear weight while walking.

Some of those adaptations, like the one Fernandez and his colleagues studied, look pretty subtle to anyone who is not a specialist in primate foot anatomy. Their study focused on how much the head of the metatarsal protrudes toward the top of the foot, sticking out above the shaft of the bone like a dome, at the joint with the phalanx (one of the bones that makes up the toes) at the base of the toe.

That Steam logo is the only outward sign that this is a Steam Machine and not an Alienware Alpha.

Valve appears to be working on a set of "compatibility tools," called Steam Play, that would allow at least some Windows-based titles to run on Linux-based SteamOS systems.

Yesterday, Reddit users noticed that Steam's GUI files (as captured by SteamDB's Steam Tracker) include a hidden section with unused text related to the unannounced Steam Play system. According to that text, "Steam Play will automatically install compatibility tools that allow you to play games from your library that were built for other operating systems."

Other unused text in the that GUI file suggests Steam Play will offer official compatibility with "supported tiles" while also letting users test compatibility for "games in your library that have not been verified with a supported compatibility tool." That latter use comes with a warning that "this may not work as expected, and can cause issues with your games, including crashes and breaking save games."

Enlarge (credit: Lisa Brewster)

Migraines suck—understatement of the year right there. Migraines are also poorly understood, and it's kind of hard to come up with effective remedies if you don’t understand what you are treating.

One way to understand migraines is through physics. The brain is a network of neurons that are constantly talking to each other. This, in physics-speak, is a dynamical system. Dynamical systems can have more than one stable operating point. A horrible consequence of this particular system might be that migraines represent a stable operating point of the brain.

No going back

A recent paper—one that isn’t especially exciting—has forced me to write about oscillating brains. I’ve talked about chaotic systems, nonlinear dynamics, and dynamical systems before. I won’t repeat everything written previously, but I do want to emphasize the concept of transitions that don’t easily reverse.