In many ways, humans are weird mammals. And our relationship with milk is especially weird.

In every mammalian species, females produce milk to feed their young. The nursing babies digest the milk with the help of an enzyme called lactase, which cuts milk sugar into easily absorbed fragments. When the young mammals are weaned, they stop making lactase. After all, why waste energy making an enzyme you no longer need?

But it is common for our species to keep consuming milk into adulthood. What’s more, about one-third of people carry genetic mutations that allow them to produce lactase throughout their lives, making it easier to digest milk. Continue reading “Early Europeans Could Not Tolerate Milk but Drank It Anyway, Study Finds” →

One of the biggest myths of evolution is that it is a relentless march of progress. In fact, evolution is not a linear track, but a branching tree. New species do not arise as part of some long-term goal; they adapt to new opportunities in their surroundings.

On Wednesday, paleontologists unveiled a fossil that proved a potent antidote for the march-of-progress myth. It was a fish that lived about 375 million years ago, when our ancestors were scaly creatures vaguely resembling giant eels, walking across mud flats with four limbs complete with elbows, knees, wrists and ankles. The newly discovered fossil, called Qikiqtania wakei, belonged to this lineage. Continue reading “These Fins Were Made for Walking … and Then Swimming” →

The Food and Drug Administration on Wednesday authorized a Covid-19 vaccine developed by Novavax, a biotechnology company in Maryland that received significant federal funding to produce the shot. The vaccine will be a new option for Americans as vaccination rates stagnate.

After two years of development, the vaccine has finally overcome manufacturing problems to become the fourth shot to earn clearance in the United States. Advisers to the Centers for Disease Control and Prevention will meet next week and are expected to discuss who should get the Novavax vaccine.

The two-dose vaccine was authorized as a primary immunization series for adults, rather than a booster, which is likely to limit its market at first. The Biden administration said earlier this week that it would buy 3.2 million doses, enough to fully vaccinate 1.6 million people in the United States. In announcing its purchase, the government said that Novavax was expected to finish its quality testing “in the next few weeks,” a necessary step before the doses are released. Continue reading “Novavax’s latecomer Covid-19 vaccine gets U.S. authorization.” →

The Biden administration announced on Monday that it would buy 3.2 million doses of a Covid-19 vaccine from the Maryland pharmaceutical company Novavax that is expected to soon receive authorization in the United States.

If cleared by regulators, Novavax’s two-dose vaccine would become the fourth coronavirus vaccine available in the United States. It would be available at first as a primary immunization series for adults. After that initial authorization, the Food and Drug Administration could later authorize the vaccine as a booster shot.

The company hopes that its protein-based shot, a vaccine technology that has been widely used for decades, will appeal to Americans who declined to be vaccinated with shots using messenger RNA technology. About two-thirds of people in the United States are fully vaccinated. Continue reading “The U.S. government will buy 3.2 million doses of Novavax’s Covid vaccine.” →