Ice Age North American big mammals’ extinction


This August 2019 video says about itself:

Until the end of the last ice age, many giants called North America home. It has long puzzled scientists why these animals and other megafauna — creatures heavier than 100 lbs. (45 kilograms) — went extinct about 10,000 years ago.
Rapid warming periods called interstadials and, to a lesser degree, ice-age people who hunted animals are responsible for the disappearance of the continent’s megafauna, according to studies.

Both research and the debate surrounding the reasons for the extinction of these animals will undeniably continue. In the meantime, researchers continue to find fossils of these massive creatures.

Here’s a look at 14 such extinct giant animals from the last North American ice age, and what scientists know about their lives.

1. North American Horses
2. Glyptodon
3. American lion
4. Smilodon fatalis
6. Mastodons
7. Mammoths
8. Giant Short-faced bear
9. Dire wolf
10. American cheetah
11. Ground sloths
12. Giant beaver
13. North American Camels

From the University of Nebraska-Lincoln in the USA:

Division by subtraction: Extinction of large mammal species likely drove survivors apart

Disappearance of mammoths, other giants likely reduced interactions of smaller mammals

September 19, 2019

Summary: A new study suggests that the extinctions of mammoths, dire wolves and other large mammal species in North America drove surviving species to distance themselves from their neighbors, reducing interactions as predators and prey, territorial competitors or scavengers. The discovery could preview the ecological effects of future extinctions, the researchers say.

When a series of large mammal species began going extinct roughly 12,000 years ago, many surviving species began going their separate ways, says new research led by Macquarie University and the University of Nebraska-Lincoln.

Published Sept. 20 in the journal Science, the study analyzed distributions of mammal fossils across North America following the last ice age, after the retreat of massive glaciers that had encroached south to the modern-day United States. The aftermath saw the disappearance of many famously large mammal species: mammoths, mastodons, saber-toothed cats, dire wolves and ground sloths, among others.

Surviving mammal species often responded by distancing themselves from their neighbors, the study found, potentially reducing how often they interacted as predators and prey, territorial competitors or scavengers.

The ecological repercussions of the extinctions are likely still echoing today and could preview the effects of future extinctions, said study co-author Kate Lyons.

“For 300 million years, the (cohabitation) pattern of plants and animals looked one way — and then it changed in the last 10,000 years,” said Lyons, assistant professor of biological sciences at Nebraska. “This paper addresses how that happened in mammal communities.

“If connectedness among species makes ecosystems more stable, what this suggests is that we’ve already lost a lot of those links. What this potentially tells us is that modern ecosystems are probably more vulnerable than we think they are.”

Led by Macquarie’s Anikó Tóth, the team analyzed records of 93 mammal species at hundreds of fossil sites during three timespans: 21,000 to 11,700 years ago, when the extinctions began; 11,700 to 2,000 years ago; and 2,000 years ago to the present. The researchers then assessed whether, and to what extent, a given species lived among each of the other 92 at those sites.

That data allowed the team to calculate how often a random pair of species would be expected to cohabit a site, providing a baseline for whether each pair overlapped more or less often than predicted by chance — aggregating vs. segregating, respectively. The proportion of aggregating pairs generally declined following the extinctions, and the strength of associations often dropped even among species that continued to aggregate, the researchers found.

“The loss of the giant carnivores and herbivores changed how small mammals such as deer, coyotes and raccoons interacted,” Tóth said. “Our work suggests that these changes were triggered by the ecological upheaval of the extinctions.”

Tóth, Lyons and their 17 co-authors effectively ruled out climate change and geography as drivers of the growing division. Surprisingly, the team also concluded that surviving species began cohabiting less frequently even as they expanded into larger swaths of their respective geographic ranges.

Lyons said the specific reasons for the seeming paradox and the overall trends are unclear, though the ecological consequences of losing species such as the mammoth could explain them. Mammoths toppled trees, compacted soil and, by eating and excreting masses of vegetation, transported nutrients around ecosystems, Lyons said. Those behaviors helped sustain the so-called mammoth steppe, an ecosystem type that once covered vast areas of the Northern Hemisphere. The loss of the mammoth effectively doomed the mammoth steppe, possibly compartmentalizing the expanses of land that hosted many species.

“If you’re an open-habitat species that used to occupy the mammoth steppe, and now the mammoth steppe has gone away, you might inhabit, say, open grassland areas that are surrounded by forests,” Lyons said. “But that meadow is much smaller. Instead of supporting 10 species, it now might support five. And if those patches of open habitat are spread farther apart, you might expand your geographic range and potentially your climate range, but you would co-occur with fewer species.”

Also uncertain: why common species became more common, and some rare species became even rarer, following the extinctions. Continuing to study the dynamics underlying such trends could help sharpen perspectives on current ecosystems and their possible fates, the researchers said.

“We had a complement of large mammals in North America that was probably more diverse than what we see in Africa today,” Lyons said. “Additional extinctions could have a cascading effect and huge implications for the mammal communities that we have left.”

Tóth, Lyons and their co-authors represent 18 institutions from Australia, the United States, Chile, Portugal, Finland, Canada and Denmark. All are members of the Evolution of Terrestrial Ecosystems Program at the Smithsonian Institution, which funded the team’s research.

This video is called The Short-Faced Bear: America’s Top Predator.

From the University of Arkansas in the USA:

Anthropologist contributes to major study of large animal extinction

September 20, 2019

As part of an international research group based at the Smithsonian Museum of Natural History, anthropology assistant professor Amelia Villaseñor contributed to a large, multi-institutional study explaining how the human-influenced mass extinction of giant carnivores and herbivores of North America fundamentally changed the biodiversity and landscape of the continent.

In their study published today in Science, researchers from Australia, the United States, Canada and Finland showed that humans shaped the processes underlying how species co-existed for the last several thousand years. Smaller, surviving animals such as deer changed their ecological interactions, the researchers found, causing ecological upheaval across the continent.

The researchers’ work has implications for conservation of today’s remaining large animals, now threatened by another human-led mass extinction.

The study’s primary author is Anikó Tóth at Macquarie University in Sydney, Australia. Tóth collaborated with Villaseñor and several other researchers at the Smithsonian’s Evolution of Terrestrial Ecosystems Program, as well as researchers at other institutions.

Tóth and the co-authors focused on how large mammals were distributed across the continent in the Pleistocene and Holocene geological epochs. (The Pleistocene Epoch occurred from about 2.5 million to 11,700 years ago. Starting at the end of the Pleistocene, the Holocene is the current geological epoch.) To do this, the researchers analyzed how often pairs of species were found living in the same community or in different communities.

To rule out community changes that were the result of reduced diversity or lost associations involving extinct species, the researchers analyzed only those pairs in which both species survived. Prior to the extinction, co-occurrence was more common. After extinction, segregations were more common.

Villaseñor’s research focuses on human fossil remains as a way to understand how human ancestors interacted with mammal communities for the last 3.5 million years. Her more recent research explores how modern humans have shaped today’s ecosystems.

“Rather than thinking of humans as separate from ‘natural’ environments, our research has illuminated the major impacts that humans have had on the ecosystem for many thousands of years,” Villaseñor said. “The results of this paper and others from our group illuminate the outsized impacts that human-mediated extinction has had in North America.”

By the end of the Late Pleistocene in North America, roughly 11,000 years ago, humans contributed to the extinction of large mammals, including mammoths and sabre-toothed cats. Recent work, driven by today’s crisis in biodiversity, has looked at understanding the ecological and evolutionary legacies of this event. There was ecological transformation across the continent — the mammoth steppe disappeared, vegetation and fire regimes changed and large carnivores were lost.

Big climate strike in Britain today


This 20 September 2019 video from England says about itself:

Pollution knows no borders’: Jeremy Corbyn addresses London climate strike

Jeremy Corbyn has called Donald Trump‘s decision to walk away from the Paris climate agreement ‘disgraceful’ in a speech to climate strikers in London.

The Labour leader said the climate emergency could only be solved by international action. ‘Destroying nature ultimately destroys all of us‘, he added.

Protesters at Britain's Student Climate Network's Global Climate Strike in Cambridge

More photos are here.

Britain: Friday, September 20, 2019: Thousands turn out for Earth Strike.

Canadian government bans African students


This 20 September 2019 video says about itself:

A shocking report has revealed that 75% of African students applying for study visas in Canada have been denied, between January and May, 2019 alone. The sadder thing for me is that so many of our young great minds still believe that the only place they can get a good education and “escape poverty” is in the West.

Red fox, snow leopard in the Himalayas


This 19 September 2019 video from the Himalayas in India says about itself:

A red fox stumbles across a treasure trove of nutrition: the carcass of a freshly killed yak. But nearby tracks reveal that its killer isn’t far away – and wouldn’t take kindly to an intruder.

Donald Trump’s ICE anti-immigrant violence


This August 2019 UNited States TV video says about itself:

Donald Trump’s ICE Chief Defends Raid Leaving Children Crying | The Beat With Ari Melber | MSNBC

In an NBC News exclusive interview, acting ICE Director Matthew Albence responds to video of an 11-year-old girl crying for her father after he was sent to detention in an ICE raid. The official blames her parents. The interview comes as Trump’s immigration chief suggests changing the Statue of Liberty poem to ‘give me your tired and your poor who can stand on their own two feet.’

By Casey Gold in the USA:

Immigrant shot by ICE agents two weeks ago detained in lawyer’s parking lot in Nashville, Tennessee

20 September 2019

On Tuesday, Immigration and Customs Enforcement (ICE) agents in Nashville, Tennessee, violently arrested 39-year-old Jose Fernando Andrade-Sanchez as he was leaving his attorney’s office. He was consulting a lawyer after having been shot and injured by ICE Enforcement and Removal agents just two weeks ago. Andrade-Sanchez is a Mexican national who has been living in the Nashville area; he now faces deportation and up to two years in prison.

The abhorrent treatment of Andrade-Sanchez by ICE agents, which has taken place in open, public spaces, is indicative of the hastening deterioration of democratic rights and the growing threat of violence toward the entire working class carried out by the Trump administration in its ongoing war on immigrants.

The September 5 incident involved two ICE agents approaching Andrade-Sanchez in his truck, which was parked in a grocery store parking lot in Antioch, Tennessee, after a traffic stop. When the agents requested that Andrade-Sanchez exit his truck, he instead drove forward. This was the impetus for one of the agents to shoot Andrade-Sanchez twice, putting him in the hospital. The agent who put Andrade-Sanchez in the hospital has not been charged or reprimanded in any way.

On September 11, a federal grand jury indicted Andrade-Sanchez for “illegal reentry”. The indictment was unsealed on Tuesday, resulting in Andrade-Sanchez’s arrest this week. ICE agents surrounded Ozment Law Firm, an immigration firm Andrade-Sanchez sought to retain for his immigration case, with guns drawn, waiting for Andrade-Sanchez to exit the office.

Aaron Dendy, an attorney at Ozment Law Firm, reported that ICE agents forced Andrade-Sanchez to the ground, despite attempts by Andrade-Sanchez himself and attorneys to inform the agents that he was still injured from ICE’s previous attack.

ICE responded to local reporters’ request for information about the treatment of Andrade-Sanchez in a short, but revealing statement, “The agents acted in accordance with federal law and policy during [Tuesday’s] arrest.”

The U.S. Attorney’s Office for the Middle District of Tennessee, where Andrade-Sanchez will be tried and sentenced to deportation, if not time in prison, issued a press release about the arrest on Tuesday. This statement details Andrade-Sanchez’s past offenses and how Andrade-Sanchez “elud[ed] apprehension”, simply noting that an agent shot and wounded Andrade-Sanchez. Ironically, the statement concludes with the statement that, “[Andrade-Sanchez] is presumed innocent until proven guilty in a court of law.”

The corporate, compliant media has completely accepted the government’s version of the story, with not one condemnation of ICE’s appalling behavior. Instead, most outlets have focused on Andrade-Sanchez’s past and the technical “illegality” of his entry to the US.

Federal prosecutors have requested that Andrade-Sanchez be held in jail while his charges pend, citing Andrade-Sanchez’s “criminal history”. This refers to the fact that Andrade-Sanchez had been deported to Mexico on four previous occasions, pleaded guilty to domestic assault in 2009, and pleaded guilty to a charge of “criminal impersonation”, for giving a fake name to a Nashville police officer, in 2013.

Andrade-Sanchez is unfortunately one of the latest but not the last victim of the state’s turn to violence in response to growing social inequality. It is no coincidence that Andrade-Sanchez faced such brutal treatment while the Trump administration and leading Democrats decry “weak borders” and stoke fear about “illegal aliens”. In fact, the treatment of Andrade-Sanchez is exactly what was called for at a Trump rally in Florida earlier this year, where Trump laughed in response to an audience member’s call to “shoot” immigrants crossing the US-Mexico border.

In a just society, there would be no restrictions on human movement, and the ICE agent who shot and wounded Andrade-Sanchez would be the one facing punishment. The US Attorney’s Office’s pathetic attempt to keep up its “democratic” veneer with a hollow reference to Andrade-Sanchez’s “presumed innocence” illustrates the role such institutions play as the ruling class becomes increasingly brutal towards workers, youth, and students.

Only a mass movement of youth, students, and the working class on an international, socialist basis can defend democratic rights and ensure the safety of the most vulnerable layers of the working class.

Less than two months ago, residents in the working-class Hermitage neighborhood in Nashville physically stopped ICE agents from arresting an immigrant father. There, the father and his son refused to exit their van, which neighbors then surrounded to prevent the arrest. It is safe to say that had there been no intervention by neighbors in that situation, the ICE agents there would not have refrained from exerting violent force against the man and his child.

ICE agents, as well as police officers and other “enforcement” arms of the state, will continue to unleash atrocities on the working class, regardless of race, nationality, gender, or any other identity. In response, the working class, youths, and students must themselves intervene and defend democratic and social rights.

Worldwide pro-climate strike today


This 20 September 2019 video from New York City in the USA says about itself:

Sept 20, 3pm ET – NYC Climate Strike with Greta Thunberg & Leading Youth Activists

From daily News Line in Britain today:

Youth and workers in global strike against climate change – Time to end the source of the crisis by overthrowing capitalism

20th September 2019

TODAY, a week of action across the world starts with a Global Climate Strike in at least 137 countries.

This follows mass action in every continent in March this year which saw tens of thousands of school students walking out of their classrooms, taking to the streets, and demanding a future.

What has a revolutionary significance in today’s strike is that it has marked a conscious turn by youth across the world towards the working class and the trade union movement.

At last week’s annual TUC Congress, young people lobbied delegates demanding support for a motion submitted by the University and College Union (UCU) which warned ‘the future of the planet is at risk if we don’t force governments to cut emissions’.

The motion, which was passed unanimously, called on workers to support today’s school student strike and for affiliated unions to organise a 30-minute workday ‘stoppage’ campaign to coincide with it.

As Sean Vernell, a member of UCU National Executive, noted: ‘It is the first time that the TUC has called on its 6.5 million members to demonstrate support for school students taking action. Indeed, it is the first time in many years the TUC has called on its members to demonstrate its collective power in solidarity with anyone.’

It was the determination of school students that forced the TUC out of its usual inactivity and start to mobilise the strength of the unions behind the climate strike.

Vernell criticised the TUC for taking out the demand for unions to organise a ‘stoppage’ from the UCU’s original motion on the grounds that a solidarity strike in support of school students would be illegal under Tory anti-union laws.

Despite the TUC leaders shying away from the call for strike action, there has been massive support throughout the country from union branches with hundreds of universities taking action along with local government unions, schools and civil service unions.

The Bakers union passed a similar motion at its recent conference. In Oxford CWU postal workers will be taking solidarity action, while BEIS workers on indefinite strike for a living wage will be joining the climate strike.

Globally, the response from workers has been massive, with over 900 workers at Amazon’s Seattle headquarters pledging to walk out over the company’s inaction over climate change – the first time in its 25-year history that [Seattle] employees have walked out. In Australia, over 1,200 businesses have been forced by this movement to pledge to enable workers to join the strike.

Young people across the world are taking action demanding a future and a change in society and, in turning to the working class and demanding the support of trade unions, they are turning to the only class that can bring about the revolutionary change in society that the climate crisis demands.

Youth know that capitalism with its insatiable drive for profit at all costs is the source of the climate change disaster, and that the only way to secure a future for young people across the world is to put an end to capitalism.

Young people are today on the march globally against a bankrupt capitalist system that in its death agony can only survive by the mass exploitation and destruction of the world’s resources through wars and pollution, while at the same time waging war against young people through unemployment and slave labour schemes.

Young people are the most revolutionary section of the working class and are in the vanguard of the struggle to overthrow capitalism and replace it with socialism. By turning out to the adult workers and unions, youth have given a massive revolutionary lead in mobilising the working class to overthrow capitalism and advance to a planned socialist economy.

Only under a planned socialist economy can the necessary steps be taken to avert the climate crisis capitalism has produced.

An internationally respected group of scientists have urgently called on world leaders to accelerate efforts to tackle climate change. Almost every aspect of the planet’s environment and ecology is undergoing changes in response to climate change, some of which will be profound if not catastrophic in the future: here.