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View of the Cape Kaliakra coastline

Rocks formed in the megalake are now cliffs overlooking the Black Sea in Cape Kaliakra, Bulgaria.Panther Media GmbH/Alamy

The largest lake the world has ever known

The megalake Paratethys once covered more than 2.8 million square kilometres, from the eastern Alps to what is now Kazakhstan. During its 5-million-year lifetime, the lake was home to many species found nowhere else, including miniature versions of whales, dolphins, and seals. As the Paratethys ebbed and grew saltier, the changes might have driven the ancestors of today’s giraffes and elephants to migrate towards the present-day African savannah. Eventually, erosion took its toll, and the megalake probably formed a spectacular waterfall as it drained into the Mediterranean Sea between 6.7 million and 6.9 million years ago.

Science | 5 min read

Reference: Scientific Reports paper & Communications Earth & Environment paper

COVID-19 coronavirus update

Two health workers carry a large crate containing COIVD-19 vaccines up a hill in Goma, Democratic Republic of Congo

A campaign to vaccinate people against COVID-19 in Goma, Democratic Republic of the Congo, in May.Credit: Guerchom Ndebo/Getty


What we’ve learnt from 1.7 billion doses

At 6:30 a.m. on 8 December 2020, a 90-year-old British woman named Margaret Keenan became the first person to receive a COVID-19 vaccine as part of a mass vaccination effort. Now, more than 1.7 billion doses later, researchers are sifting through the data to address lingering questions about how well the vaccines work — and how they might shape the course of the coronavirus pandemic, which has already taken more than 3.5 million lives.

Nature | 15 min read

UNEQUAL PROTECTION. Graph showing that wealthier nations have secured an inordinate share of vaccine supplies.

Source: Our World in Data


School outbreak offers cautionary tale

This month, science journalist Linda Geddes experienced a COVID-19 outbreak at her children’s primary school that ultimately infected her whole family. She warns that, even in the United Kingdom, where vaccines are plentiful, it’s too soon to get complacent. She explores the role of primary-age children in driving community transmission and the possibility that outbreaks in schools are an early sign that cases are going undetected in the wider community. “The virus is out there, passing from person to person, even if it looks like it is not. Even if we pretend it is on the brink of being over,” says Geddes.

The Guardian | 8 min read


Uncertainty and the ‘lab leak’ theory

In this episode of Coronapod, Nature’s Noah Baker and Amy Maxmen delve into the idea that SARS-CoV-2 could have originated in a laboratory in China. They consider whether the way in which complex and nuanced science is communicated could be fuelling an increasingly fraught debate, and explore what the fallout might be for international collaboration.

Nature Coronapod Podcast | 16 min listen

Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts or Spotify.

Notable quotable

“I really hope that [mask wearing] becomes part of our culture and that we are more conscious of how even mild infections can potentially impact other people.”

US virologist Angela Rasmussen hopes that the considerate practice of wearing a face covering when you’re feeling ill — already commonplace in many regions — becomes a post-pandemic habit everywhere. (Scientific American | 4 min read)

Features & opinion

Mathematicians answer: will it crush?

Mathematicians have revealed the threshold at which certain shapes can be crushed without becoming creased or distorted. The work helps to explain a pioneering idea from Nobel-laureate John Nash: you can crumple a sphere down to a ball of any size, without tearing it or using crisp folds. (The key is to add infinitely many smooth twists to its surface and put it in a higher-dimensional space.) The new findings are an important step to understanding sharp transition points in a variety of systems, such as when a flow becomes turbulent.

Quanta | 11 min read

Reference: Advances in Mathematics paper & arXiv preprint

Quote of the day

“This is the very first time in our 77-year history of honouring animals that we will have presented a medal to a rat.”

A landmine-sniffing rat named Magawa is retiring after helping to clear more than 22 hectares in Cambodia. Magawa won an award from the People's Dispensary for Sick Animals, a veterinary charity, after finding 71 landmines and 38 items of unexploded ordnance. (NPR | 4 min read)