Gemini Man and Replicas: two movies with big name stars and big budgets, and writers who know nothing about science.

I’m reading this recent article on Population genomics of the Viking world, the one with a bazillion authors, and it’s nice and well done, but the popular press seems to find it surprising, when it’s pretty much what I would have expected.

The maritime expansion of Scandinavian populations during the Viking Age (about AD 750-1050) was a far-flung transformation in world history1,2. Here we sequenced the genomes of 442 humans from archaeological sites across Europe and Greenland (to a median depth of about 1×) to understand the global influence of this expansion. We find the Viking period involved gene flow into Scandinavia from the south and east. We observe genetic structure within Scandinavia, with diversity hotspots in the south and restricted gene flow within Scandinavia. We find evidence for a major influx of Danish ancestry into England; a Swedish influx into the Baltic; and Norwegian influx into Ireland, Iceland and Greenland. Additionally, we see substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. Our ancient DNA analysis also revealed that a Viking expedition included close family members. By comparing with modern populations, we find that pigmentation-associated loci have undergone strong population differentiation during the past millennium, and trace positively selected loci-including the lactase-persistence allele of LCT and alleles of ANKA that are associated with the immune response-in detail. We conclude that the Viking diaspora was characterized by substantial transregional engagement: distinct populations influenced the genomic makeup of different regions of Europe, and Scandinavia experienced increased contact with the rest of the continent.

Well, yes. If my Scandinavian ancestors were all tall, blue-eyed, blonde- and red-haired giants out of a Frazetta painting, how did I end up with this [sweeps hand dramatically over frumpy body] particular genetic complement? Why are my relatives so…variegated? I’ve been to Norway, and the people there are wonderfully diverse. This result should be what we all expected — and the scientists who did it were certainly unsurprised, just appreciative of the data — but somehow, the stories in the popular press all about how this upsets stereotypes. Like this one, “Vikings may not be who we thought they were, DNA study finds”.

History books typically depict Vikings as blue-eyed, blonde-haired, burly men sailing the North Atlantic coast to pillage wherever they set foot on land. While some of that may be true, a new genetic study of Viking DNA is flipping much of this history on its head.

In the largest genetic study of Viking DNA ever, scientists have found that Vikings — and their diaspora — are actually much more genetically diverse than we may have thought and were not necessarily all part of a homogenous background.

Notice what the title and the opening paragraph do: they center the story on public misconceptions about a group of humans. I guess “Humans had children with other humans” isn’t quite as exciting as “Cartoon version of ancient people isn’t quite accurate”. The real interesting question, other than the science of the study, is about how pervasive racist myths are.

It’s all about gene flow, which is important and interesting and pretty much universal, and not at all scary, all you white supremacists out there with your phony Asatru tattoos.

Finally, our findings show that Vikings were not simply a direct continuation of Scandinavian Iron Age groups. Instead, we observe gene flow from the south and east into Scandinavia, starting in the Iron Age and continuing throughout the duration of the Viking Age, from an increasing number of sources. Many Viking Age individuals—both within and outside Scandinavia—have high levels of non-Scandinavian ancestry, which suggests ongoing gene flow across Europe.

I wish I could hang around for a thousand years to see the results of anthropological studies of American graveyards. “History books typically depict Americans as obese, orange-skinned, and profoundly stupid, lying and cheating their way to exploit other people’s wealth. While some of that may be true, a new genetic study is revealing that they were much more diverse and complex than that.”

It’s in all the best webcomics!

I’ll take Paul Lynde for the center square, please. (oops, dated myself.)

Finding phosphine in the atmosphere of Venus is interesting, and it sure sounds like the scientists who found it were all cautious and conservative and thorough, so I believe them that it’s there. I have a couple of caveats about how it’s interpreted, though. Phosphine can be produced abiotically — it’s found in the atmosphere of Jupiter, for instance — but it takes a lot of energy in reactions that weren’t thought to occur on Venus, but that could be the “weird high-heat chemistry” the comic mentions. It’s also produced biotically, on Earth by the decay of organic matter, but here it’s only a small component, and it’s also fairly rapidly broken down by sunlight. So we’re postulating huge quantities of organic matter decaying on Venus to produce phosphines, or an unusual organic process that produces persistent phosphines from a small quantity of biomass? I don’t know. Sounds unlikely and strange, but I love to see unlikely and strange.

No matter what, though, don’t expect Venusian cloud-cities and communicative aliens. Phosphine is a flammable, toxic gas, and at best we’re seeing the excretions of bacteria-like organisms, and even that is not likely.

Last chance to support a fun science project, Crow Scientist, the real-world science app for kids. Go read about it, it looks good!