In the dark abyss of the ocean, animals cannot afford to be choosy. The odds of bumping into another individual are low, and appropriate willing mates are even harder to come by. To deal with this problem, the deep-sea squid Octopoteuthis deletron has become somewhat indiscriminate. The males will mate with any squid they come across, whether they’re male or female.
Hendrik Hoving from the Montery Bay Aquarium Research Institute found evidence of these same-sex matings with a robot submarine. Controlled from a surface ship, these vehicles can explore depths that humans cannot. The subs have captured videos of O.deletron since 1992 (videos here), but the team have only just revealed the nature of the squid’s sex life by studying the archival footage.
I recently wrote a piece about a bird called the greater honeyguide, whose chicks brutally murder those of other birds. But honeyguides are better known for a more helpful behaviour – leading humans to bee hives. The people break open the hives and leave behind an otherwise inaccessible piece of honey for the bird.
In the post, I mentioned that the honeyguide also has an alliance with that darling of silly internet memes, the honey badger. I first heard that honeyguides lead honey badgers to bee hives when I was a child, and I’ve seen the fact repeated ever since. I have even seen footage of their interaction on a wildlife documentary.
Others apparently have too. When I tweeted about my honeyguide post, Joe Hanson replied with “Typical of a honey badger ally.” Wikipedia, that font of all knowledge, says, “[Honeyguides] are also well known for leading the honey badger, or ratel, to bee hives in eastern Africa.” And for those tutting at Wikipedia, this particular fact also shows up in an authoritative textbook on African birds and David Attenborough’s The Life of Birds.
Unfortunately, it’s not true.
When scientists struggle with a problem for over a decade, few of them think, “I know! I’ll ask computer gamers to help.” That, however, is exactly what Firas Khatib from the University of Washington did. The result: he and his legion of gaming co-authors have cracked a longstanding problem in AIDS research that scientists have puzzled over for years. It took them three weeks.
Khatib’s recruits played Foldit, a programme that reframes fiendish scientific challenges as a competitive multiplayer computer game. It taps into the collective problem-solving skills of tens of thousands of people, most of whom have little or no background in science. Here’s what I wrote about Foldit last year:
Imagine you’re living off the coast of California, and you want to get to sunny Florida. That sounds easy enough, but there are three big problems in this imaginary scenario. First, you are a snail, so crossing even a small distance takes a lot of time. Second, there is a continent in the way. Third, you are a sea snail so you are not adapted to crawling on land.
These problems seem insurmountable and yet snails have made the journey. Osamu Miura from the Smithsonian Tropical Research Institute has found that horn snails crossed from the Pacific to the Atlantic Ocean around 750,000 years ago, while other individuals made the opposite journey around 72,000 years ago. And they probably flew on bird airlines.
Some parents give their children a head start in life by lavishing them with money or opportunities. The mother seed beetle (Mimosestes amicus) does so by providing her children with shields to defend them from body-snatchers.
A female seed beetle abandons her eggs after laying them. Until they hatch, they are vulnerable to body-snatching parasites, like the wasp Uscana semifumipennis. It specialises on seed beetle eggs and lays its own eggs inside. Once the wasp grub hatches, it devours its host. The wasp problem is so severe that around 70 percent of the beetles’ eggs can be infested.
But the mother seed beetles have a defence, and it is a unique one. Joseph Deas and Molly Hunter from the University of Arizona have found that they can protect an egg from this grisly fate by laying another one on top. Sometimes, the mothers lay entire stacks of two or three eggs. The tops ones are always flat and unviable. They never hatch into grubs and they completely cover the ones underneath.
The Nile crocodile is a truly iconic animal. Or, more accurately, two iconic animals. As I’ve just written over at Nature News:
The iconic Nile crocodile actually comprises two different species — and they are only distantly related. The large east African Nile crocodile (Crocodylus niloticus) is in fact more closely related to four species of Caribbean crocodile than to its small west African neighbour, which has been named (Crocodylus suchus).
Evon Hekkala of Fordham University in New York and her colleagues revealed evidence for the existence of the second species by sequencing the genes of 123 living Nile crocodiles and 57 museum specimens, including several 2,000-year-old crocodile mummies.
The results resolve a centuries-old debate about the classification of the Nile crocodile, and have important implications for the conservation of both species.
If you ask someone to guess the number of sweets in a jar, the odds that they’ll land upon the right number are low – fairground raffles rely on that inaccuracy. But if you ask many people to take guesses, something odd happens. Even though their individual answers can be wildly off, the average of their varied guesses tends to be surprisingly accurate.
This phenomenon goes by many names – swam intelligence, wisdom of the crowd, vox populi, and more. Whatever it’s called, the principle is the same: a group of people can often arrive at more accurate answers and better decisions than individuals acting alone. There are many examples, from counting beans in a jar, to guessing the weight of an ox, to the Ask The Audience option in Who Wants to be a Millionaire?
But all of these examples are somewhat artificial, because they involve decisions that are made in a social vacuum. Indeed, James Surowiecki, author of The Wisdom of Crowds, argued that wise crowds are ones where “people’s opinions aren’t determined by the opinions of those around them.” That rarely happens. From votes in elections, to votes on social media sites, people see what others around them are doing or intend to do. We actively seek out what others are saying, and we have a natural tendency to emulate successful and prominent individuals. So what happens to the wisdom of the crowd when the crowd talks to one another?
Tens of thousands of years ago, our ancestors spread across the world, having sex with Neanderthals, Denisovans and other groups of ancient humans as they went. Today, our genes testify to these prehistoric liaisons. Last year, when the Neanderthal genome was finally sequenced, it emerged that everyone outside of African can trace 1 and 4 percent of their DNA from Neanderthals.
The discovery was a vindication for some and a surprise to others. For decades, palaeontologists had fought over different visions of the rise of early humans. Some championed the “Out of Africa” model, which says that all of us descend from a small group of ancestors who came out of Africa, swept the world, and replaced every other group of early humans. The most extreme versions of this model said that these groups never had sex, or at least, never bred successfully. The alternative – the multiregional model – envisages these prehistoric groups as part of a single population that met and mated extensively.
To an extent, these are caricatured versions of the two models, and there are subtler variants of each. Still, early evidence seemed to support the extreme Out of Africa version. When scientists sequenced the mitochondrial genome of Neanderthals (a small secondary set of genes set apart from the main pack), they found no evidence that any of these sequences had invaded the modern human genome. The conclusion: Neanderthals and humans never bred.
The full Neanderthal genome disproved that idea, but it also shifted the question from whether humans had sex with Neanderthals to just how much sex they had. As I mentioned in New Scientist earlier this year, modern humans were spreading into areas where Neanderthals existed. “It doesn’t necessarily take a lot of sex for genes from a resident population to infiltrate the genomes of colonisers. When an incoming group mates with an established one, the genes they pick up quickly rise to prominence as their population grows.”
Now, Mathias Currat from the University of Geneva and Laurent Excoffier from the University of Berne have weighed into the debate. They simulated the spread of modern humans from Africa and their encounters with Neanderthals throughout Europe and Asia, to work out the levels of sex that would have transferred Neanderthal genes to modern genomes at their current level.