In this week’s Weird Science, we question men’s role in evolution after a female shark just reproduced asexually—after years of being an empowered, sexual woman. After that, we ponder coffee’s role in helping us live longer. And finally, we give thanks to the researchers who embarked on the much-needed journey to tie the tightest knot in the world.
No Man Required:
Female Sharks Can Reproduce Sexually and Asexually
A female shark in Queensland, Australia shocked scientists this week when it impregnated herself … after years of being separated from her mate.
Leonie, a species of zebra shark, has lived in Reef HQ aquarium in Townsville, Queensland, since 1999. Between 2008 and 2012, Leonie enjoyed the company of a certain male zebra shark, the father of her pups. In 2012, her boy toy was moved to a separate tank to control the couple’s rampant breeding.
Starting in 2014, Leonie began laying eggs containing embryos. None of the hatchlings survived. In 2015, the same scenario occurred. And, oddly, in April 2016, three babies hatched. Puzzled, scientists presumed Leonie had stored her previous partner’s sperm for years—leopard sharks have been known to carry sperm for up to four years. But, after testing the baby sharks’ DNA, genetic testing showed Leonie’s babies only carried her DNA, the result of asexual reproduction—not some old baby-daddy sperm.
Now, sharks have long-been known to reproduce asexually, but, it was the shift from sexual to asexual reproduction that shocked the scientists.
“Leonie adapted to her circumstances and we believe she switched because she lost her mate,” said Christine Dudgeon, lead author of the study at the University of Queensland, “This has big implications for conservation and shows us how flexible the shark’s reproductive system really is.”
The next steps for the research team are to determine if the pops, produced asexually, can switch to sexual reproduction once mature. If they can, what could this mean for evolution and the role of men?
Should We Care?
Researchers Tie the World’s Tightest Knot
Well, this happened, and it wasn’t even a constrictor knot! Researchers—probably insanely bored researchers—at the University of Manchester have tied the most tightly knotted physical structure known to man. It contains eight crossings in a 192-atom closed loop, is about half a nanometer across, about 10,000-times thinner than human hair.
Unlike tying your shoelaces, the team used the chemical process of “self-assembly” to grab the ends and begin knotting. Mixing molecular buildings blocks with metal ions and a chloride ion solution, the assembly forces the molecular building blocks to latch onto the sticky, metal ions, in a knitting-like fashion—think of it like hair-braiding on steroids.
Why would we ever need such a tight knot?
Does it matter? It’s the world’s tightest fucking knot. Really, though, the knotting technique could be used to make new, ridiculously strong everyday materials that can stretch in different directions, hold their shape, while remaining light and strong.
Lead researcher Professor David A. Leigh hopes to use these concepts to weave molecular strands to make plastics and polymers.
For example Kevlar, used in bulletproof vests, body armor, car brakes, and parts of aircraft bodies, is a super-tough polymer with a chemical structure that consists of tiny straight molecular rods that pack close together, like pencils packed tightly in a pencil case. If we can weave molecular strands into molecular fabrics maybe we will be able to get the same sort of strength with a lighter and more flexible material.
Told You So:
Coffee is Pretty Much the Way to Immortality
Is coffee bad for you? Surely something that perks you up and initiates a morning shit can’t be all that bad?
A study out of Stanford University now suggests that caffeine, specifically in coffee, can target and combat inflammatory processes involved with aging and age-related diseases. The researchers noted that caffeine fights the body’s harmful metabolites—basically, the shitty (often quite literally) byproducts of metabolic reactions in your body—like any antibody would fight an illness, and, actually, incubating immune cells with caffeine literally helps fight these inflammatory-triggering, bastard metabolites.
It’s well known that coffee-intake correlates with longevity. Previous research has shown that, among elders, those who drank more caffeinated beverages like coffee tended to live longer than those who didn’t. But now it’s known exactly how coffee fights—quite literally—to keep you alive.
Image: brian, CC-BY
is a travel writer, part-time hitchhiker, and he’s currently trying to imitate Where in the World is Carmen San Diego but with more sunscreen and jorts.