International

Oldest human relative walked upright 7 mn years ago: study

AFP

The earliest known human ancestor walked on two feet as well as climbing through trees around seven million years ago, scientists said Wednesday after studying three limb bones.

When the skull of Sahelanthropus tchadensis was discovered in Chad in 2001, it pushed back the age of the oldest known representative species of humanity by a million years.

Nicknamed “Toumai”, the nearly complete cranium was thought to indicate that the species walked on two feet because of the position of its vertebral column and other factors.

However the subject triggered fierce debate among scientists, partly due to the scarcity and quality of the available bones, with some even claiming that Toumai was not a human relative but just an ancient ape.

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In a study published in the Nature journal on Wednesday, a team of researchers exhaustively analysed a thigh bone and two forearm bones found at the same site as the Toumai skull.

“The skull tells us that Sahelanthropus is part of the human lineage,” said paleoanthropologist Franck Guy, one of the authors of the study.

The new research on the limb bones demonstrates that walking on two feet was its “preferred mode of getting around, depending on the situation,” he told a press conference.

But they also sometimes moved through the trees, he added.

– ‘Not a magical trait’ –

The leg and arm bones were found alongside thousands of other fossils in 2001, and the researchers were not able to confirm that they belonged to the same individual as the Toumai skull.

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After years of testing and measuring the bones, they identified 23 characteristics which were then compared to fossils from great apes as well as hominins — which are species more closely related to humans than chimpanzees.

They concluded that “these characteristics are much closer to what would be seen in a hominin than any other primate,” the study’s lead author Guillaume Daver told the press conference.

For example, the forearm bones did not show evidence that the Sahelanthropus leaned on the back of its hands, as is done by gorillas and chimpanzees.

The Sahelanthropus lived in an area with a combination of forests, palm groves and tropical savannahs, meaning that being able to both walk and climb through trees would have been an advantage.

There have been previous suggestions that it was the ability to walk on two feet that drove humans to evolve separately from chimpanzees, putting us on the path to where we are today.

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However the researchers emphasised that what made Sahelanthropus human was its ability to adapt to its environment.

“Bipedalism (walking on two legs) is not a magical trait that strictly defines humanity,” paleontologist Jean-Renaud Boisserie told the press conference.

“It is a characteristic that we find at the present time in all the representatives of humanity.”

– Our ‘bushy’ family tree –

Paleoanthropologist Antoine Balzeau of France’s National Museum of Natural History said the “extremely substantial” study gives “a more complete image of Toumai and therefore of the first humans”.

It also bolstered the theory that the human family tree is “bushy”, and was not like the “simplistic image of humans who follow one another, with abilities that improve over time,” Balzeau, who was not involved in the research, told AFP.

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Daniel Lieberman, a professor of human evolutionary biology at Harvard University, said in a linked paper in Nature that the study’s “authors have squeezed as much information as possible from the fossil data”.

But he added that the research will not offer “full resolution” of the debate.

Milford Wolpoff, a paleoanthropologist at the US University of Michigan cast doubt on whether Toumai is a hominin, telling AFP that “extraordinary claims require extraordinary evidence”.

Wednesday’s study was carried out by researchers from the PALEVOPRIM paleontology institute, a collaboration between France’s CNRS research centre and Poitiers University, as well as scientists in Chad.

Guy said the team hopes to continue its research in Chad next year — “security permitting”.

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Chadian paleontologist Clarisse Nekoulnang said the team was “trying to find sites older than that of Toumai”.

International

Guatemala considers sending high-risk gang members to military prisons

Amid the escalating crisis in Guatemala’s prison system, the government is considering transferring high-risk gang members to military-run detention facilities, a move that analysts say could help address overcrowding and the lack of control in civilian prisons.

The debate has gained urgency following the killing of ten police officers by gang members, reportedly in retaliation after the government refused to meet demands made by Aldo Dupie Ochoa, alias “El Lobo,” leader of the Barrio 18 gang, which authorities identified as responsible for the attack.

Guatemala’s Minister of Defense, Henry David Sáenz, told local media that the possibility of relocating high-danger inmates to military brigades has not been formally discussed. However, he noted that the practice is not new to the Armed Forces and said it is something that “was already being done.”

One example is the detention center located within the Mariscal Zavala Military Brigade, in Zone 17 of Guatemala City, where several inmates are held under military supervision. The facility also houses high-profile detainees, including former official Eduardo Masaya, who faces corruption charges.

In 2015, a ministerial agreement authorized the establishment of the Zone Seventeen Detention Center within the brigade, with a maximum capacity of 114 inmates in Area A and 21 in Area B. The agreement specified that the facility would be used exclusively for civilians or military personnel considered at risk of assassination.

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Additionally, since 2010, a prison has operated within the Matamoros Barracks in Zone 1 of Guatemala City, holding dangerous or high-profile inmates. However, media outlets have described these military detention centers as “VIP prisons,” particularly for former government officials such as ex-president Otto Pérez Molina.

International

Rights group says over 5,000 killed in Iran protests, mostly civilians

A U.S.-based human rights group said on Friday it has confirmed that more than 5,000 people were killed during the recent protests in Iran, most of them civilians allegedly shot by security forces.

Non-governmental organizations monitoring the toll from the crackdown on what have been described as the largest demonstrations in Iran in years said their work has been hampered by an internet shutdown imposed by authorities since January 8. They warned that the actual death toll is likely significantly higher.

The Human Rights Activists News Agency (HRANA), based in the United States, reported on Friday that it had verified the deaths of 5,002 people, including 4,714 protesters, 42 minors, 207 members of the security forces, and 39 bystanders.

The group added, however, that it is still investigating an additional 9,787 possible deaths, underscoring the difficulty of independently confirming information amid ongoing restrictions and repression.

International

Japan reopens Kashiwazaki-Kariwa Plant despite public concerns

La centrale nucléaire japonaise de Kashiwazaki-Kariwa, la plus grande au monde, a repris ses activités mercredi pour la première fois depuis la catastrophe de Fukushima en 2011, malgré les inquiétudes persistantes d’une partie de la population.

La remise en service a eu lieu à 19h02 heure locale (10h02 GMT), a indiqué à l’AFP Tatsuya Matoba, porte-parole de la compagnie Tokyo Electric Power (Tepco).

Le gouverneur de la préfecture de Niigata, où se situe la centrale, avait donné son feu vert à la reprise le mois dernier, en dépit d’une opinion publique divisée. Selon une enquête menée en septembre par la préfecture elle-même, 60 % des habitants se déclaraient opposés au redémarrage, contre 37 % favorables.

Mardi, plusieurs dizaines de manifestants ont bravé le froid et la neige pour protester près de l’entrée du site, sur les rives de la mer du Japon.

« L’électricité de Tokyo est produite à Kashiwazaki. Pourquoi seuls les habitants d’ici devraient-ils être exposés au danger ? Cela n’a aucun sens », a déclaré à l’AFP Yumiko Abe, une riveraine de 73 ans.

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La centrale de Kashiwazaki-Kariwa avait été mise à l’arrêt lorsque le Japon a fermé l’ensemble de ses réacteurs nucléaires à la suite du triple désastre de mars 2011 — un séisme, un tsunami et un accident nucléaire — survenu à Fukushima.