Showing posts with label Climate change. Show all posts
Showing posts with label Climate change. Show all posts

Friday, 28 March 2025

How Aboriginal People Survived The Last Ice Age

Found on Sovereign Union's Facebook Page here: https://www.facebook.com/photo/?fbid=1083452677155134&set=a.642304697936603



A 2013 published study revealed how First Nations people coped with the last Ice Age, roughly 20,000 years ago.

"Population numbers plummeted due to harsh conditions at the peak of the last Ice Age", says the study.

Researchers say that when the climate cooled dramatically, Aboriginal groups sought refuge in well-watered areas, such as along rivers, and populations were condensed into small habitable areas.

Professor Sean Ulm, lead author of the research at James Cook University in Townsville, says the vast majority of Australia was simply uninhabitable at this time. "Forests disappeared, animals went extinct; major areas of Australia would have been deprived of surface water."

To understand how Aboriginal people responded to the conditions, a team of experts from Australia, England, and Canada used the radiocarbon dates of thousands of archaeological sites to study the distribution of people across the landscape over time.

The findings, published recently in The Journal of Archaeological Science[1], suggest that about 21,000 years ago, almost all people in modern-day Australia migrated into smaller areas, abandoning as much as 80 per cent of the continent.

"In Lawn Hill Gorge in northwestern Queensland, at the coldest point of the last glacial period, all of the stone, raw materials and food remains are exclusively from the Gorge area," says Sean. "This indicated very limited or no use of the surrounding broader landscape."

This massive consolidation had drastic effects on the population as well. "There was likely a birth rate decline of over 60 per cent," says Alan Williams, a PhD student at the Australian Nation University who worked on the study. "It would have been very ugly."

Can humans cope with climate change?

Sean says the next step would ideally be to study the resulting cultural shifts, however, this may prove to be difficult given that close to one third of what was Australia at the time of the Ice Age is now underwater. "By 10,000 years ago, sea levels were visibly rising, sometimes on a daily basis," says Sean.

Extreme changes in the environment continued for thousands of years, and Aboriginal life readjusted in the process. Sean says this makes it unlikely that researchers will ever know the full societal ramifications of the Ice Age.

What the study does reveal, however, is that humans have withstood massive climate change on this continent in the past, and this might prove vital for preparing for future events.

"A lot of the current climate reports that we read about in Australia...their records only go back a couple of hundred years," says Sean. "That's a very short time span to base our model for future climate change on."

Sean adds that, thanks to studies like this, archaeologists may soon have the potential to extend these data sets.

- Article - Reasearch Paper review by Wes Judd 'Australian Geographic' 27 September 2013

[1] RESEARCH PAPER: 'Human refugia in Australia during the Last Glacial Maximum and Terminal Pleistocene: a geospatial analysis of the 25–12 ka Australian archaeological record'

- By ALAN N.WILLIAMS James Cook University,
- ANDREW R.COOK University of New South Wales;
- MICHELLE C. LANGLEY University of Oxford, UK;
- MARK COLLARDE Human Evolutionary Studies Program and Department of Archaeology, British Columbia, Canada:

[ Academic Paper: https://bit.ly/34Atr6L ]

IMAGES:
Top: Southeast Asia and Australia during the last Ice Age.
Bottom: Estimations the areas in which Aboriginal groups congregated during the last Ice Age. (Source of both images - the above academic article)

Friday, 8 January 2021

Ancient news roundup

Africa (Olduvai Gorge):

Research suggests that early man (c. 2 million years ago) was able to manage in a changing environment for 200,000 years. 

'The findings uncovered at Oldupai Gorge and across eastern Africa indicate that early human movements across and out of Africa were possible by 2 million years ago, as hominins possessed the behavioural ability to expand into novel ecosystems.' 

Part of this may be due to the use of stone tools, technology which (it is speculated) may have been employed by other hominin species such as australopithecines:

'... we know that the genus Paranthropus was present in Oldupai Gorge at this time.'

Tibet:

DNA from the hominin species knows as Denisovans has been found in sediment in Baishiya Karst Cave on the Tibetan plateau - the first such find outside Siberia. The specimens date from c. 100,000 years ago, again from 60,000 years ago, and possibly also 50k-30k ya; in the latter case that may have overlapped with the arrival of modern humans and interbreeding there or elsewhere could explain why 'present-day Tibetans carry a gene variant that aids high-altitude survival'.

https://www.google.com/maps/place/35%C2%B026'53.0%22N+102%C2%B034'17.0%22E/@32.0753123,90.6411118,4.75z/data=!4m5!3m4!1s0x0:0x0!8m2!3d35.448056!4d102.571389?hl=en

https://en.wikipedia.org/wiki/Denisovan#/media/File:Early_migrations_mercator.svg

Conflict between Homo Sapiens and the Neanderthals

An academic at Bath University suggests there was a 100,000-year war between the two species that pitched modern humans against the Neanderthals that had preceded them out of Africa and were already thriving in Europe and Asia:
South Africa

Article on early man in southern South Africa 200,000 years ago, when sea levels were lower - the hunting grounds since partially inundated following the end of the Ice Age:
Peru

It seems prehistoric women could be hunters, as well as gatherers:

Dogs and humans

Parallel DNA research into human and canine genomes is sketching an 11,000-year-long (or more) history of their relationship. The five separate dog genomes have expanded to 32:

https://www.sciencemag.org/news/2020/10/how-dogs-tracked-their-humans-across-ancient-world

Dingoes, on the other hand, seem to have arrived in western Australia some 3,500 years ago - far later than humans - and although some were recorded living with aboriginals in 1788 they don't feature much in ancient rock art; perhaps for roving hunter-gatherers dingoes were an unaffordable luxury?

https://en.wikipedia.org/wiki/Dingo

Monday, 7 September 2020

What happened on Easter Island (Rapa Nui); a lesson for global overpopulation

'The demographic declines of the Rapa Nui are linked to the long-term effects of climate change on the island's capacity for the production of food... 

'We did not find traces of an idyllic equilibrium with nature, and we did not find traces of a huge collapse. Instead, we found traces of interactions between three factors: Climate change, human population size, and changes in the ecosystem. The climate change manifests itself as a long-term pattern of changes in rainfall over some 400 years. The population grew during this same period, and the islanders also increased and changed their use of natural resources and agricultural methods...

'The islanders were not only aware of the changes, but they were also able to change the way the lived on the island. They gradually changed from the quite complex society that raised the marvelous moai statues, to a later and simpler agrarian society with reduced family sizes and a new way of producing food in stone gardens...

'These three factors affected the population on Rapa Nui, and they are also important on a global scale. We studied Rapa Nui and its history because we are trying to understand what is happening with the planet. Everybody talks about climate change and the resulting problems, but very few people are talking about the rising global population and the problems it causes.'

https://phys.org/news/2020-09-growth-decline-rapa-nui-population.html

Friday, 14 August 2020

MADAGASCAR: Ancient site threatened by climate change



The Conversation reports the threat to African heritage sites posed by climate change:
https://theconversation.com/these-african-world-heritage-sites-are-under-threat-from-climate-change-144140

'Villages and towns associated with the historic Swahili Indian Ocean trading networks are all forecast to suffer significant loss from sea-level rise and coastal erosion in the coming decades...

'A host of unique heritage locations are built on coral, sand or mud – all at elevations less than 10 metres above sea level.'

Among these sites is Mahilaka, the first major urban center and trading port in Madagascar, which was settled by Austronesians in the first millennium CE. Mahilaka is on the northwest coast. Archaelogical evidence is in the form of human artefacts, but also crop species not native to Africa, and maybe even linguistic traces in the Bantu language. There are indications that the neighbouring Comoros islands may have shared some of this Pacific (among others) immigration history.
https://www.pnas.org/content/113/24/6635

https://www.researchgate.net/figure/Overview-of-the-inferred-history-of-Madagascar-Descriptions-and-dates-are-given-in-A-D_fig6_318500759

Monday, 3 August 2020

TAIWAN, bridge to the Pacific islands; and the multiple impacts of climate change

Aside from archaeological finds, there are several other threads connecting prehistoric Taiwan with the spread of humans through the Pacific island chains.

One is the paper mulberry tree, native to Taiwan and Japan, which the Austronesian migrants took with them because they used its fibrous bark to make their cloth. A 2015 study of its genes supports the hypothesis that the species in Oceania are descended from those in Asia.
  https://raskisimani.files.wordpress.com/2013/01/broussonetia-paper-mulberry.pdf
  https://taiwantoday.tw/news.php?post=26541&unit=20%2C29%2C35&unitname=Taiwan-Review&postname=Austronesian-Roots&fbclid=IwAR0rEsePB0aR71MtPstwKguoqx-ZFsHNlw9r5JM0N0h1PbGW1kfIk849PF4

Another is linguistics. Professor Robert Blust https://en.wikipedia.org/wiki/Robert_Blust sorts the many languages of Taiwan into ten groups, only one of which (Malayo-Polynesian) developed into the Austronesian family of tongues.
  https://en.wikipedia.org/wiki/Austronesian_languages#Blust_(1999)
  https://en.wikipedia.org/wiki/Malayo-Polynesian_languages#Major_languages

A third is the study of human genes. A 2014 study of mitochondrial DNA from a c. 8,000-year-old skeleton unearthed on an island off the Chinese mainland links China to Taiwan and Austronesia.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3951936/

Figure 1: The Liangdao Man Skeleton (picture from here)
The same study suggests a prehistoric migration route as illustrated below, from an area where foxtail millet began to be cultivated (around what is now modern Beijing), to the region where rice was domesticated (surrounding modern Shanghai), to what is now Fuzhou on the mainland (1), on to Liangdao island (2), across to Taiwan (3) and then down to the Philippines (4) and beyond:


(Ibid., adapted from Figure 5)

How did these humans cross over from the mainland? At its narrowest, the Taiwan Strait is about 130 kilometres (80 miles) between Fujian and Taiwan.

Things were different in the last Ice Age. The Strait is now some 100 metres deep, but:
'Pleistocene glaciations lowered [the] sea level 140m in the East China Sea 15,000 years ago, forming a land bridge between Taiwan and the mainland, with Palaeolithic artifacts on both sides. In the initial Holocene 10,000 years ago, melting ice raised the East China Sea 100m, quickly forming the Taiwan Strait.' 
- from 'The Neolithic Taiwan Strait', by Kuang-chih Chang (1989)
https://web.archive.org/web/20120418153210/http://http-server.carleton.ca/~bgordon/Rice/papers/App.18ChangKC89.pdf

'Permafrost covered Asia as far south as Beijing,' says Wikipedia, so perhaps early humans were motivated to go further south, and some willing and able to walk over the exposed land between China and Taiwan.
https://en.wikipedia.org/wiki/Last_Glacial_Maximum#Asia

The end of the Ice Age saw rising sea levels: 'After the last ice age about 20,000 years ago, sea level initially rose due to the melting of the glaciers. That peaked around 4,000 to 5,000 years ago,' says geologist Chip Fletcher in this 2017 interview:
https://e360.yale.edu/features/as-seas-rise-tropical-pacific-islands-face-a-perfect-storm

One might think that this flooding was a spur to the development of boats, but although the earliest found by archaeological excavation date back 7,000 - 10,000 years, other evidence suggests that they existed tens of thousands of years earlier.
https://en.wikipedia.org/wiki/Boat#History
Indeed, recent finds in Central America suggest that homo sapiens may have arrived by sea 20,000 - 30,000 years ago and spread north and south from there, rather than coming though the Alaskan/Canadian ice corridor as previously thought:
http://polynesiantimes.blogspot.com/2020/07/origins-americas-first-colonised-in.html

Contrary to what one might assume, the post-glacial flooding was not uniform in all times and places. As the vast weight of ice was lifted from the land the continental plates started to shift about and rise up further from the Earth's mantle, like a ship being emptied of cargo. 'At the same time that Polynesians were undergoing their journeys of exploration and discovery, 1,000 to 3,000 years ago, sea level was falling and exposing coastal plains that then became habitable, where previously the sea was up against clay banks or cliffs,' says Fletcher. 'In the Pacific region [after c. 4,000-5,000 years ago], sea level started to fall until a few centuries ago. And now global warming is causing sea levels to rise again.'
https://e360.yale.edu/features/as-seas-rise-tropical-pacific-islands-face-a-perfect-storm

Although falling sea levels may have made it easier to land boats, 'around AD 1300 there was rapid global cooling, which was followed shortly by rapid sea-level fall – perhaps as much as 50-70 cm within 100 years in the Pacific [...]
   'In almost every island group in the Pacific - from Solomon Islands and Fiji in the west to Rapa and Easter Island in the east – the first signs of collapse appear around AD 1300 with almost all hill forts beginning to be occupied around AD 1400. [...] 
   'Rapid sea-level fall along Pacific island coasts would have lowered coastal water tables, slowed water circulation within lagoons and killed (through exposure) the most productive parts of coral reefs. A food crisis would have resulted for coastal dwellers. Conflict followed. So people fled inland where they stayed, more or less, for several hundred years.'
https://theconversation.com/rise-and-fall-social-collapse-linked-to-sea-level-in-the-pacific-56268

So the interaction between geography, climate and human history is unexpectedly complex.