Those lush little wads of greenery in your yard have it hard. To reproduce, male mosses must release their sperm into the dew and wait for them to trickle into a female moss, which is a separate plant altogether. Perhaps, if they’re lucky, the sperm might be given a lift by tiny arthropods called springtails, making their way through the moss patch.
Why the springtails get involved in this slow-motion seduction hasn’t been clear. But now researchers have found that just as flowers release scents that attract bees, butterflies, and other pollinators, so too does the humble moss lure in the springtail with its own special secretions.
You may have heard the G-spot buzz today: a gynecological surgeon claims to have discovered an actual structure in a vagina that corresponds to this reputed female pleasure center. Just by itself, any invocation of the G-spot should set off alarms; it has been called a “gynecologic UFO: much searched for, much discussed, but unverified by objective means.”
There is much about this particular study, though, that is deeply troubling, as best exposed by Ricki Lewis, who has authored textbooks on human physiology, at Scientific American. Here is a quick sum-up of what is so wrong about this situation.
Big Problem #1
The Y chromosome, at the bottom right of this set of human
chromosomes, is dwarfed by the X.
Over the last few decades, scientists and journalists have speculated that the end of man—men, that is—was nigh. The biological reason for this possibility is the ever-shrinking Y chromosome: 300-200 million years ago, the Y, like females’ X chromosome, had hundreds of genes, but it now contains less than 80, 19 of which code for specifically male traits such as sperm production. This remarkable contraction set people’s imaginations spinning, especially after an opinion piece said in Nature 10 years ago that the Y chromosome might disappear, as it already has in voles, in 10 million years.
A Nature paper published this week, however, may indicate that the Y is sticking around. Biologists at the Whitehead Institute have compared the Y chromosome of rhesus monkeys with the human Y chromosome, and they’ve found that the two have the same number but one of key male-specific genes. This implies that the human Y chromosome’s shrinkage, at least when it comes to key genes, stopped at least around 25 million years ago, when the common ancestor of humans and rhesus monkeys was alive. The team says that this 25 million years of stasis indicates that the Y’s days of sloughing genes are over, that the genes it carries now are the essential ones and cannot be removed without seriously impacting reproductive function, while the genes lost in the past were expendable.
What’s the News: In the squid world, the body size of male spear squid determines the mating strategies they use. Small male squid, which have no chance of physically competing with their larger rivals, must try to get with the females of the species on the sly. Now, researchers in Tokyo have learned that this difference in mating behavior has resulted in the evolution of divergent sperm types, though perhaps not in the way you’d think: diminutive male squid actually produce larger sperm than big male squid.