Archiv: Homo Sapiens


04.09.2024 - 14:20 [ frontiersin.org ]

When and Why Did Human Brains Decrease in Size? A New Change-Point Analysis and Insights From Brain Evolution in Ants

(22 October 2021)

But we also find that human brain size reduction was surprisingly recent, occurring in the last 3,000 years. Our dating does not support hypotheses concerning brain size reduction as a by-product of body size reduction, a result of a shift to an agricultural diet, or a consequence of self-domestication. We suggest our analysis supports the hypothesis that the recent decrease in brain size may instead result from the externalization of knowledge and advantages of group-level decision-making due in part to the advent of social systems of distributed cognition and the storage and sharing of information. Humans live in social groups in which multiple brains contribute to the emergence of collective intelligence. Although difficult to study in the deep history of Homo, the impacts of group size, social organization, collective intelligence and other potential selective forces on brain evolution can be elucidated using ants as models.

04.09.2024 - 13:15 [ Welt.de ]

Evolution: Das ist der Grund, wieso die Gehirne der Menschen schrumpfen

(16.11.2021)

Dass unser Gehirn langsam etwas an Masse verloren hat, ist jedoch nicht ganz so lange her: Erst vor rund 3.000 Jahren begann es zu schrumpfen.

(…)

Die Art und Weise, wie sich Individuen in einem Ameisenstaat organisieren, ähnelt unseren modernen Gesellschaftsstrukturen. Die Insekten haben, verglichen mit ihrer Körpergröße, ein Mini-Gehirn. Es ist etwa eine Million Mal kleiner als das eines Menschen – sie können aber Großes leisten. Das Prinzip dahinter ist eine Art kollektive Intelligenz. Nicht jeder muss alles können oder wissen, es gibt eine klare Aufgabenteilung.

26.04.2024 - 02:35 [ Smithsonian Magazine ]

An Evolutionary Timeline of Homo Sapiens

(February 2, 2021)

Neanderthals once stretched across Eurasia from Portugal and the British Isles to Siberia. As Homo sapiens became more prevalent across these areas the Neanderthals faded in their turn, being generally consigned to history by some 40,000 years ago. (…)

Despite the bits of genetic ancestry they contributed to living people, all of our close relatives eventually died out, leaving Homo sapiens as the only human species. Their extinctions add one more intriguing, perhaps unanswerable question to the story of our evolution—why were we the only humans to survive?

26.04.2024 - 01:30 [ PRI.org ]

Scientists link Earth’s magnetic reversals to changes in planet’s life and climate

(April 19, 2021)

The researchers examined the rings of the tree to look for changes in the amount of carbon-14 over a period of years, Gramling explains. Carbon-14 is useful not only for dating things, but because the interaction of cosmic rays with molecules in the atmosphere produces a lot of it. And when the Earth has a weakened magnetic field, more cosmic rays hit the planet.

The scientists indeed found a large spike in carbon-14 in the tree, which they could then compare with the rock record that indicated a magnetic reversal. (…)

In addition, there is the documented rise in cave art right about 41,000-42,000 years ago, Gramling points out.

17.04.2024 - 20:26 [ New York Times ]

Ukraine Sees ‘Hypocrisy’ in Western Allies’ Defense of Israel

The militaries of the United States, Britain, France and others stepped in to help Israel defend against the fusillade of more than 300 Iranian drones and missiles, nearly all of which were intercepted. A similar number of aerial weapons are fired at Ukraine on a weekly basis, its officials say, with many of the drones in those attacks designed by Iran and now produced by Russia.

17.04.2024 - 19:42 [ SRF.ch ]

Hilfe für die Ukraine – Selenski fordert, was Israel bekam

Israel parierte den iranischen Grossangriff aus der Luft – und zwar mithilfe der USA, Grossbritanniens, Frankreichs, Jordaniens und möglicherweise Saudi-Arabiens. Genau solche Hilfe fordert nun der ukrainische Präsident Wolodimir Selenski für sein Land gegen die russischen Luftangriffe. Das ist legitim. Doch passieren wird es nicht.

30.01.2024 - 11:30 [ Reuters ]

Elon Musk‘s Neuralink implants brain chip in first human

The study uses a robot to surgically place a brain-computer interface (BCI) implant in a region of the brain that controls the intention to move, Neuralink said previously, adding that its initial goal is to enable people to control a computer cursor or keyboard using their thoughts alone.

30.01.2024 - 11:25 [ Futurism.com ]

Neuralink Is Now Recruiting Human Subjects

(20.09.2023)

It‘s only a tiny incremental step towards Musk‘s sweeping vision for his company‘s brain chip. In 2020, Musk promised Neuralink devices could solve numerous neurological conditions, including addiction or memory loss, or restore movement for people with spinal cord injuries. He‘s even promised that one day, a Neuralink brain chip could allow for human-to-human telepathy.

In short, despite Musk‘s grand ambitions, Neuralink still has a lot of work to do to catch up with its competitors — and isn‘t about to completely revolutionize the field just yet.

20.09.2023 - 03:49 [ European Bioinformatics Institute / European Molecular Biology Laboratory ]

A more diverse human reference genome

(10 May 2023)

The work was led by the international Human Pangenome Reference Consortium (HPRC), a group funded by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH) and consisting of 14 institutes, including EMBL’s European Bioinformatics Institute (EMBL-EBI). (…)

The majority of the genomes used to create the human pangenome reference were collected as part of the 1000 genomes project, the largest public catalogue of human variation and genotype data from a wide range of populations. (…)

In order to understand the differences in the genes present across the individual genomes represented in the human pangenome, researchers in EMBL-EBI’s Ensembl team needed to map the high-quality annotations on the reference human genome generated as part of the GENCODE project, across the pangenome.

20.09.2023 - 03:12 [ Wikipedia ]

1000 Genomes Project

Some genomic differences may not affect fitness. Neutral variation, previously thought to be “junk” DNA, is unaffected by natural selection resulting in higher genetic variation at such sites when compared to sites where variation does influence fitness.[14]

It is not fully clear how natural selection has shaped population differences; however, genetic candidate regions under selection have been identified recently. (…)

It was found that on average, each person carries around 250–300 loss-of-function variants in annotated genes and 50-100 variants previously implicated in inherited disorders. Based on the two trios, it is estimated that the rate of de novo germline mutation is approximately 10−8 per base per generation.

20.09.2023 - 02:51 [ National Library of Medicine / National Institutes of Health (NIH) ]

The 1000 Genomes Project: Welcome to a New World

(Dec 2015)

“Now this is not the end… But it is, perhaps, the end of the beginning” as Winston Churchill said. Large-scale sequencing projects will continue for more regional or ethnic groups, in order to extend the global coverage. Much effort will focus on a better understanding of the relationship between genetic variation and common disorders. The translation of this massive genetic information to human health will benefit from the development of complex databases gathering genetic, clinical, and biological data, such as multi-omics profiles, while maintaining protection of potentially sensitive personal information (3). Efforts are also underway to increase genetic awareness in the public and to educate health professionals

20.09.2023 - 02:12 [ GENCODE project ]

GENCODE

The goal of the GENCODE project is to identify and classify all gene features in the human and mouse genomes with high accuracy based on biological evidence, and to release these annotations for the benefit of biomedical research and genome interpretation.

20.09.2023 - 01:45 [ European Molecular Biology Laboratory ]

DeepMind and EMBL release the most complete database of predicted 3D structures of human proteins

(22 July 2021)

For those scientists who rely on experimental protein structure determination, AlphaFold’s predictions have helped accelerate their research. For example, a team at the University of Colorado Boulder is finding promise in using AlphaFold predictions to study antibiotic resistance, while a group at the University of California San Francisco has used them to increase their understanding of SARS-CoV-2 biology.

The AlphaFold Protein Structure Database builds on many contributions from the international scientific community, as well as AlphaFold’s sophisticated algorithmic innovations and EMBL-EBI’s decades of experience in sharing the world’s biological data. DeepMind and EMBL’s European Bioinformatics Institute (EMBL-EBI) are providing access to AlphaFold’s predictions so that others can use the system as a tool to enable and accelerate research and open up completely new avenues of scientific discovery.

09.09.2023 - 18:41 [ Times of Israel ]

Government tells High Court nullifying ‘reasonableness’ law will result in ‘anarchy’

In its brief, the government argues that the court lacks statutory authority to annul Israel’s quasi-constitutional Basic Laws, and therefore any such verdict would be based on unlegislated and unclear “basic principles.”

“All government institutions may argue that they have the right to determine what these principles mean. It is a short path from here to anarchy,” the brief said

23.05.2023 - 13:31 [ Unlimited Hangout ]

The Revenge of the Malthusians and the Science of Limits

(June 28, 2022)

Davos-man Yuval Harari has echoed these sentiments, arguing that the levers of evolution will now be moved from the randomness of nature into the new gods running Google, Facebook and the WEF.

In a 2018 WEF sermon, Harari acted as a neo-Darwinian prophet of a new transhumanist age, saying:

“We are probably among the last generations of homo sapiens. Within a century or two, Earth will be dominated by entities that are more different from us, than we are different from Neanderthals or from chimpanzees. Because in the coming generations, we will learn how to engineer bodies and brains and minds. These will be the main products of the 21st century economy.”

24.04.2023 - 13:21 [ Science.org ]

A global environmental crisis 42,000 years ago

(19 Feb 2021)

Do terrestrial geomagnetic field reversals have an effect on Earth‘s climate? Cooper et al. created a precisely dated radiocarbon record around the time of the Laschamps geomagnetic reversal about 41,000 years ago from the rings of New Zealand swamp kauri trees. This record reveals a substantial increase in the carbon-14 content of the atmosphere culminating during the period of weakening magnetic field strength preceding the polarity switch. The authors modeled the consequences of this event and concluded that the geomagnetic field minimum caused substantial changes in atmospheric ozone concentration that drove synchronous global climate and environmental shifts.

(…)

We precisely characterize the geomagnetic reversal and perform global chemistry-climate modeling and detailed radiocarbon dating of paleoenvironmental records to investigate impacts. We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

24.04.2023 - 13:16 [ ORF.at ]

Erdmagnetfeld: Polwanderung veränderte das Weltklima

Ungefilterte Strahlung aus dem Weltraum zerriss Luftpartikel in der Erdatmosphäre, trennte Elektronen ab und emittierte Licht. Diese ionisierte Luft brutzelte die Ozonschicht weg, heißt es in einer Presseaussendung zur Studie. In Folge dürften überall auf dem Globus Polarlichter aufgetaucht sein, nicht nur rund um den geographischen Nord- und Südpol wie heute. (…)

Das Erdmagnetfeld schwächelt bereits seit rund 2.000 Jahren wieder. Verglichen mit den ersten direkten Messungen vor 170 Jahren wurde eine Abschwächung um neun Prozent festgestellt, im Bereich des Südatlantiks sogar um dreißig Prozent.

26.01.2023 - 13:38 [ Archive.org ]

1984

»Ich weiß nicht – kann es nicht sagen. Irgendwie wird es euch fehlschlagen. Etwas macht euch einen Strich durch die Rechnung. Das Leben macht euch einen Strich durch die Rechnung.«

»Wir kontrollieren das Leben, Winston, in allen seinen Äußerungen. Sie bilden sich ein, es gebe so etwas wie die sogenannte menschliche Natur, die durch unser Tun beleidigt sein und sich gegen uns auflehnen werde. Aber wir machen die menschliche Natur.

Die Menschen sind unendlich gefügig. Oder vielleicht sind Sie wieder auf Ihre alte Idee zurückgekommen, daß die Proletarier oder die Sklaven aufstehen und uns stürzen werden. Schlagen Sie sich das aus dem Kopf. Sie sind hilflos wie die Tiere. Die Menschheit ist die Partei und die Menschheit ist nur noch ein Brei.

25.09.2022 - 18:16 [ UkraineFrontlines.com ]

Kamikaze drones serial production has started in Ukraine

(14.08.2022)

Earlier, Yuriy Kasyanov wrote that a serial production of attack drones will start in Ukraine without the participation of the state. People believed, gave money, gave furniture, machine tools, tools, hoods, soldering irons, oscillographs.

Serial production of kamikaze drones. 8 pieces were made, 10 pieces are under production, components were purchased for 38 pieces.

According to the plan, up to 100 pieces can be produced in September, 2022.

25.09.2022 - 18:12 [ NavalPost.com ]

Russian Navy Ships Get More Powerful with Kamikaze drones

(October 30, 2021)

As previously reported by the Ministry of Defense, an exercise was staged in Kamchatka in October, during which they rehearsed providing fire support for troops arriving on the coast. Unmanned kamikaze and unmanned aircraft were employed for the first time during the maneuvers. Their assistance destroyed the conditional enemy’s personnel and equipment. In addition, certain kinds of Russian hovering munitions have already been tested in the field.

The Cube and Lancet drones, in particular, were deployed in Syria. Bekkhan Ozdoev, industrial director of Rostec’s weapons complex, stated that kamikaze drones have proven to be successful tools on the battlefield due to their advantages in Syria

25.09.2022 - 18:08 [ Newsweek ]

How Bigger Kamikaze Drones Expected From U.S. Could Boost Ukraine‘s Fight

(22.08.2022)

A U.S. research and development contract for 10 larger, long-range Switchblade 600 kamikaze drones is expected to be awarded within the next 30 days, according to a Monday Defense News report citing Pentagon spokeswoman Jessica Maxwell. The U.S. has already supplied Ukraine with hundreds of smaller Switchblade 300 and Phoenix Ghost drones, which are able to „loiter“ in an area and conduct surveillance for hours before reaching a target and detonating.

25.09.2022 - 18:04 [ RepublicWorld.com ]

What are Kamikaze drones? All about ‚Suicide Drones‘ which US might transfer to Ukraine

(2022-03-16)

US President Joe Biden is considering sending US-made Kamikaze drones, also dubbed as suicide or killer drones, to war-hit Ukraine as part of $1 billion security assistance. According to reports, Biden is considering sending lightweight and ultramodern Kamikaze drones, which can fly up to 40 minutes then bomb a target.

‚Switchblade‘ drones will likely placate Ukrainian President Zelenskyy as the US has repeatedly opposed his calls for a no-flight zone over Ukraine, fearing that it could spread the war.

14.09.2022 - 17:44 [ Kultur-Zentner.de ]

Kabarettist Martin Großmann: „In der Kleinkunst ist eine Underground-Szene entstanden“

Dabei schlüpft der Kabarettist wieder in die Rolle verschiedener Figuren, die das thematisieren, was seit über zweieinhalb Jahren in Deutschland passiert. Die Geschichten beruhen auf wahren Begebenheiten, werden jedoch ein wenig überhöht. Großmann sieht in diesen Audio-Aufnahmen eine weitere Möglichkeit, künstlerisch aktiv zu bleiben. „Es ist spannend, was sich durch die Krise auftut“, beschreibt er seine Situation. Trotz der Strapazen und Enttäuschungen sieht der Kabarettist die Corona-Zeit als sehr wertvoll an. Noch nie, so Großmann, habe er über die Spezies Mensch soviel lernen dürfen wie in den letzten zwei Jahren.

25.10.2021 - 17:04 [ PRI.org ]

Scientists link Earth‘s magnetic reversals to changes in planet‘s life and climate

(April 19, 2021)

The researchers examined the rings of the tree to look for changes in the amount of carbon-14 over a period of years, Gramling explains. Carbon-14 is useful not only for dating things, but because the interaction of cosmic rays with molecules in the atmosphere produces a lot of it. And when the Earth has a weakened magnetic field, more cosmic rays hit the planet.

The scientists indeed found a large spike in carbon-14 in the tree, which they could then compare with the rock record that indicated a magnetic reversal. (…)

In addition, there is the documented rise in cave art right about 41,000-42,000 years ago, Gramling points out.

25.10.2021 - 16:58 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

04.10.2021 - 05:20 [ Geophysical Research Letters 35(16) / researchgate.net ]

Magnetic effect on CO 2 solubility in seawater: A possible link between geomagnetic field variations and climate

(August 2008)

Correlations between geomagnetic-field and climate parameters have been suggested repeatedly, but possible links are controversially discussed. Here we test if weak (Earth-strength) magnetic fields can affect climatically relevant properties of seawater. We found the solubility of air in seawater to be by 15% lower under reduced magneticfield (20 mT) compared to normal field conditions (50 mT). The magnetic-field effect on CO2 solubility is twice as large, from which we surmise that geomagnetic field variations modulate the carbon exchange between atmosphere and ocean. A 1% reduction in magnetic dipole moment may release up to ten times more CO2 from the surface ocean than is emitted by subaerial volcanism.

20.09.2021 - 05:45 [ PRI.org ]

Scientists link Earth‘s magnetic reversals to changes in planet‘s life and climate

(April 19, 2021)

The researchers examined the rings of the tree to look for changes in the amount of carbon-14 over a period of years, Gramling explains. Carbon-14 is useful not only for dating things, but because the interaction of cosmic rays with molecules in the atmosphere produces a lot of it. And when the Earth has a weakened magnetic field, more cosmic rays hit the planet.

The scientists indeed found a large spike in carbon-14 in the tree, which they could then compare with the rock record that indicated a magnetic reversal. (…)

In addition, there is the documented rise in cave art right about 41,000-42,000 years ago, Gramling points out.

06.09.2021 - 18:51 [ sites.google.com/a/fivestarschools.org ]

The difference between a vaccine and medication

A vaccine is a prevention against any bacteria or viruse. It can act like an agent to protect your body from becoming sick. It can slso weakened antibody production.

(…)

Medication is any substance or substances used in treating disease or illness.

24.08.2021 - 07:56 [ Centers for Disease Control and Prevention - CDC.gov ]

When You’ve Been Fully Vaccinated

(27.08.2021)

– If you’ve had close contact with someone who has COVID-19, you should get tested 3-5 days after your exposure, even if you don’t have symptoms. You should also wear a mask indoors in public for 14 days following exposure or until your test result is negative. You should isolate for 10 days if your test result is positive.

(…)

What We Know

– COVID-19 vaccines are safe and effective at preventing COVID-19, including severe illness and death.
– COVID-19 vaccines are effective against severe disease and death from variants of the virus that causes COVID-19 currently circulating in the United States, including the Delta variant.
– Infections happen in only a small proportion of people who are fully vaccinated, even with the Delta variant. When these infections occur among vaccinated people, they tend to be mild.
– If you are fully vaccinated and become infected with the Delta variant, you can spread the virus to others.
– People with weakened immune systems, including people who take immunosuppressive medications, may not be protected even if fully vaccinated.

24.08.2021 - 07:49 [ apnews.com ]

Study: Vaccinated people can carry as much virus as others

(30.07.2021)

In another dispiriting setback for the nation’s efforts to stamp out the coronavirus, scientists who studied a big COVID-19 outbreak in Massachusetts concluded that vaccinated people who got so-called breakthrough infections carried about the same amount of the coronavirus as those who did not get the shots.

24.08.2021 - 07:39 [ sites.google.com/a/fivestarschools.org ]

The difference between a vaccine and medication

A vaccine is a prevention against any bacteria or viruse. It can act like an agent to protect your body from becoming sick. It can slso weakened antibody production.

(…)

Medication is any substance or substances used in treating disease or illness.

10.08.2021 - 10:48 [ PRI.org ]

Scientists link Earth‘s magnetic reversals to changes in planet‘s life and climate

(April 19, 2021)

The researchers examined the rings of the tree to look for changes in the amount of carbon-14 over a period of years, Gramling explains. Carbon-14 is useful not only for dating things, but because the interaction of cosmic rays with molecules in the atmosphere produces a lot of it. And when the Earth has a weakened magnetic field, more cosmic rays hit the planet.

The scientists indeed found a large spike in carbon-14 in the tree, which they could then compare with the rock record that indicated a magnetic reversal. (…)

In addition, there is the documented rise in cave art right about 41,000-42,000 years ago, Gramling points out.

10.08.2021 - 09:22 [ KalteSonne.de ]

Sechster Klimareport des IPCC enttäuscht auf ganzer Linie

Genauso kurios ist, dass der Bericht nun beim Extremwetter ziemlich sicher eine menschengemachte Komponente sieht. Das ist schon ziemlich verrückt, denn die meisten Extremwetterarten besitzen in den letzten 150 Jahren gar keinen Trend. Und die Modelle von Friederike Otto und Mitstreitern scheitern regelmäßig bei der Aufgabe, die Extremwetterentwicklung der letzten vorindustriellen Jahrtausende abzubilden. Mit diesen fehlerhaften Modellen wird dann die „Attribution“ also Zuordnung von Mensch vs. Natur vorgenommen. Das ist wie Fahren ohne Führerschein. Der AR6 behandelt das unwahrscheinliche RCP 8.5-Emissionsszenario als wenn es eine plausible Möglichkeit wäre. Ein schwerer Fehler, der Politiker und andere Nichtspezialisten fehlinformiert. Nun wird die Luft dünn für den IPCC, denn mit einer ergebnisoffenen, neutralen Zusammenfassung des Wissensstandes hat der AR6 nichts zu tun. Nur die EINE Seite des wissenschaftlichen Meinungsspektrums ist enthalten. Kritiker durften von vorneherein nicht mitschreiben. Sie konnten als Gutachter ihren Frust abladen und ihre Kritik aufschreiben. Die landete jedoch direkt im Papierkorb. Denn berücksichtigt wurde davon nichts. Die Gutachterpolizei („Review Editors“) sind nämlich vom gleichen politischen Gremium gewählt worden wie die Autoren, dem IPCC Vorstand. Und der wird von den Regierungen gewählt, vor allem den grün-geprägten Umwelministerien der Länder.

10.08.2021 - 09:12 [ Donna Laframboise / Youtube ]

The IPCC: Where‘s the Science?

(Mar 11, 2014)

The UN‘s climate panel claims to be a ‚scientific body.‘ But it‘s actually in the business of writing reports that rely on thousands of judgment calls. It‘s time to stop pretending that fallible human judgment is ‚science.‘

10.08.2021 - 08:50 [ Donna Laframboise / nofrakkingconsensus.com ]

3 Things Scientists Need to Know About the IPCC

(01.09.2015)

The bottom line is that this is a week of naked political horse trading that goes on behind closed doors. Journalists are not allowed to witness what takes place, which is why we’ve been looking at official IPCC photos here. This is what they permit us to see.

It’s only after the diplomats have haggled over this Summary – paragraph by paragraph – that the final version gets officially released at a press conference.

The world is then told that science has spoken. But what’s just happened has nothing to do with science. Scientific truth is not determined in the dead of night by UN-level negotiations. On what planet would such an approach make scientific sense?

But the bad news doesn’t stop there. There’s actually a step in the IPCC process in which the original, lengthy report gets amended so that it conforms to the politically-negotiated Summary. I am not making this up.

15.07.2021 - 10:15 [ Donna Laframboise / nofrakkingconsensus.com ]

3 Things Scientists Need to Know About the IPCC

(01.09.2015)

The bottom line is that this is a week of naked political horse trading that goes on behind closed doors. Journalists are not allowed to witness what takes place, which is why we’ve been looking at official IPCC photos here. This is what they permit us to see.

It’s only after the diplomats have haggled over this Summary – paragraph by paragraph – that the final version gets officially released at a press conference.

The world is then told that science has spoken. But what’s just happened has nothing to do with science. Scientific truth is not determined in the dead of night by UN-level negotiations. On what planet would such an approach make scientific sense?

But the bad news doesn’t stop there. There’s actually a step in the IPCC process in which the original, lengthy report gets amended so that it conforms to the politically-negotiated Summary. I am not making this up.

15.07.2021 - 09:24 [ PRI.org ]

Scientists link Earth‘s magnetic reversals to changes in planet‘s life and climate

(April 19, 2021)

The researchers examined the rings of the tree to look for changes in the amount of carbon-14 over a period of years, Gramling explains. Carbon-14 is useful not only for dating things, but because the interaction of cosmic rays with molecules in the atmosphere produces a lot of it. And when the Earth has a weakened magnetic field, more cosmic rays hit the planet.

The scientists indeed found a large spike in carbon-14 in the tree, which they could then compare with the rock record that indicated a magnetic reversal. (…)

In addition, there is the documented rise in cave art right about 41,000-42,000 years ago, Gramling points out.