Nov. 23: A brain 'car wash' could prevent neurological diseases and more…
Octopus camouflage, dog brain sizes, dark energy and life's emergence, and the evolution of kissing
On this week's episode of Quirks & Quarks with Bob McDonald:
Octopuses have the remarkable ability to change their appearance in the blink of an eye — assuming new skin colouration and patterns for camouflage or communication. A new study in the journal PNAS has explored how much energy this takes, and it turns out transforming themselves is a harder workout than you'd ever get at the gym. Kirt Onthank is a professor of Biology at Walla Walla University and known as The Octopus Guy on social media.
Dog bodies and brain sizes vary enormously, but a new study comparing dogs' cognitive abilities and personalities with brain size reveals some surprises. The research, led by evolutionary biologist Ana Balcarcel, found that the biggest brains relative to their body sizes belong to the small, anxious and excitable companion dogs, while the trainable, obedient working breeds are not gifted when it comes to volume of brain tissue. The work was published in the journal Biology Letters.
Our universe might seem like it's perfectly tuned for life, but when it comes to the role dark energy plays in the emergence of life, it turns out that our universe might not be so special after all. A new study that simulated the development of hypothetical universes with different amounts of dark energy suggests the optimal amount of dark energy to enable the evolution of life is only one-tenth of the density in our universe. Daniele Sorini, a postdoctoral researcher at Durham University and his team published their work in Monthly Notices of the Royal Astronomical Society.
Lip mashing is an oddity in the animal kingdom. Other than humans, few species have adopted the custom of pressing lips together as a signal of affection. A new theory for why humans kiss suggests it emerged from primate grooming practices, and the lip-lock has its roots in us slurping up parasites we've combed from a companion's fur. Adriano Lameira, an evolutionary psychologist at the University of Warwick, published his new hypothesis in the journal Evolutionary Anthropology.
Some scientists think it's possible that a host of neurological disorders, from Alzheimer's to Parkinson's, could be connected to problems with the way the brain rids itself of its waste. A couple of recent studies in Nature may help solve this longstanding puzzle of how this waste removal system works and what we might be able to do about it when it doesn't.
One study describes how synchronized electrical waves help flush brain waste out when we sleep. Jonathan Kipnis, a neuroimmunologist at Washington University in St. Louis, said our neurons are driving this waste removal system through what's known as the glymphatic system.
A separate study explores how gamma frequency stimulation, at 40 cycles per second, can kick-start gamma waves that are compromised in the brains of people with Alzheimer's. Li-Huei Tsai, a neuroscientist from MIT, said they found this stimulation can flush out amyloid peptides in the brains of mice that would otherwise build up and form plaques which is a hallmark of Alzheimer's brains.
