The fossilized remains of microbes that lived beside the sea in the earliest chapter of life on Earth have been discovered in a slab of rock in Western Australia.
Researchers found the tiny fossils in rock formations that date to 3.4 billion years ago, making them strong candidates to be the oldest microbes found. Some clung to grains of sand that had gathered on one of the first known stretches of beach on Earth.
The findings paint a picture of life arising when the first landmasses began to emerge in fragmentary fashion from the oceans, much like the Caribbean or Indonesian islands today.
At the time, volcanic eruptions spewed gas and lava, while a blanket of thick cloud grayed the skies. The moon — much closer then than it is today — pulled the oceans into vast tidal surges. There was no breathable oxygen.
“To us it would have seemed like a hellish place to live,” said Martin Brasier at Oxford University, who co-authored a report on the fossils in the journal Nature Geoscience. “To early life, this was paradise. A true Eden.”
Brasier worked with a team led by David Wacey at the University of Western Australia, who discovered the fossils in the region’s Strelley Pool formation, one of the oldest outcrops of sedimentary rock on Earth.
High magnification images showed the fossils were spherical, oval and tubular, much like modern microbes, and were of similar size, between 0.01mm and 0.02mm across.
Researchers who study the origin of life on Earth typically draw on several strands of evidence to support their findings. Apart from the size and shape of the fossilized microbes, Wacey points to carbon and nitrogen in their cell walls, a hallmark of all living things today.
Further evidence comes from the cells forming chains and clusters, and clinging to grains of sand. Inside some fossils were exquisitely fine structures that appear as microbes grow and divide. Some of the microbes are likely to have fed off pyrite, a sulfur-rich iron compound, and produced sulphate as a waste product. Others used this sulphate and produced hydrogen sulphide, the gas that smells like rotten eggs.
“The new evidence from our research points to earliest life being sulfur-based, living off and metabolizing compounds containing sulfur rather than oxygen for energy and growth,” Wacey said.
Unraveling the nature of the world’s oldest organisms will help scientists write the first chapter of life on Earth and aid the search for life elsewhere. Future missions to Mars, for example, might focus on ancient beaches and river sands.
“It is vital to know what the most simple life on our planet looked like and how to unambiguously identify it, if we are to have any chance of identifying life elsewhere,” Wacey said.
Le Tuan Binh keeps his Moroccan soldier father’s tombstone at his village home north of Hanoi, a treasured reminder of a man whose community in Vietnam has been largely forgotten. Mzid Ben Ali, or “Mohammed” as Binh calls him, was one of tens of thousands of North Africans who served in the French army as it battled to maintain its colonial rule of Indochina. He fought for France against the Viet Minh independence movement in the 1950s, before leaving the military — as either a defector or a captive — and making a life for himself in Vietnam. “It’s very emotional for me,”
The Chinese Communist Party’s (CCP) Central Committee is to gather in July for a key meeting known as a plenum, the third since the body of elite decisionmakers was elected in 2022, focusing on reforms amid “challenges” at home and complexities broad. Plenums are important events on China’s political calendar that require the attendance of all of the Central Committee, comprising 205 members and 171 alternate members with Chinese President Xi Jinping (習近平) at the helm. The Central Committee typically holds seven plenums between party congresses, which are held once every five years. The current central committee members were elected at the
Indian Prime Minister Narendra Modi reaffirmed his pledge to replace India’s religion-based marriage and inheritance laws with a uniform civil code if he returns to office for a third term, a move that some minority groups have opposed. In an interview with the Times of India listing his agenda, Modi said his government would push for making the code a reality. “It is clear that separate laws for communities are detrimental to the health of society,” he said in the interview published yesterday. “We cannot be a nation where one community is progressing with the support of the Constitution while the other
CODIFYING DISCRIMINATION: Transgender people would be sentenced to three years in prison, while same-sex relations could land a person in jail for more than a decade Iraq’s parliament on Saturday passed a bill criminalizing same-sex relations, which would receive a sentence of up to 15 years in prison, in a move rights groups condemned as an “attack on human rights.” Transgender people would be sentenced to three years’ jail under the amendments to a 1988 anti-prostitution law, which were adopted during a session attended by 170 of 329 lawmakers. A previous draft had proposed capital punishment for same-sex relations, in what campaigners had called a “dangerous” escalation. The new amendments enable courts to sentence people engaging in same-sex relations to 10 to 15 years in prison, according to the