Wednesday, August 9, 2017

Modern Humans Reached Indonesia Shortly After The Toba Erruption

The Toba mega volcano eruption took place about 75,000 to 74,000 years ago.
Toba Lake in northern Sumatra is the world's largest active volcanic caldera. The volcanic eruption that resulted in Lake Toba (100 x 30 km) 74,000 years ago, is known to have been by far the biggest eruption of the last 2 million years. This mega-bang caused a prolonged world-wide nuclear winter and released ash in a huge plume that spread to the north-west and covered India, Pakistan, and the Gulf region in a blanket 1–5 metres (3–15 feet) deep. Toba ash is also found in the Greenland ice-record and submarine cores in the Indian Ocean, allowing a precise date marker. . . . the Toba eruption is the most accurately dated, dramatic, and unambiguous event before the last ice age.
Very shortly after that eruption, we find the oldest reliably dated modern human presence in what is now called Sumata, Indonesia, which is in Island Southeast Asia. We also know that modern humans were present in India prior to the Toba eruption based upon lithic tools of types (of the same type across the Toba ash barrier) associated only with modern humans that have been found both above and below Toba ash there.

It seems likely that the Toba eruption opened up a biogeographic barrier that had confined modern humans to India before then, possibly by thinning out dense forests and shrinking existing hominin populations in the region. 

I'd love to see ancient DNA from the teeth sampled here to see if they had Denisovan admixture, to look at the timing of their Neanderthal admixture, and to see how much of the genetic diversity present in these samples is still found in Southeast Asian populations. It would also clarify the timing of different waves of migration associated with particular uniparental genetic markers.
Genetic evidence for anatomically modern humans (AMH) out of Africa before 75 thousand years ago (ka) and in island southeast Asia (ISEA) before 60 ka (93–61 ka) predates accepted archaeological records of occupation in the region. Claims that AMH arrived in ISEA before 60 ka have been supported only by equivocal or non-skeletal evidence AMH evidence from this period is rare and lacks robust chronologies owing to a lack of direct dating applications, poor preservation and/or excavation strategies and questionable taxonomic identifications. 
Lida Ajer is a Sumatran Pleistocene cave with a rich rainforest fauna associated with fossil human teeth. The importance of the site is unclear owing to unsupported taxonomic identification of these fossils and uncertainties regarding the age of the deposit, therefore it is rarely considered in models of human dispersal. 
Here we reinvestigate Lida Ajer to identify the teeth confidently and establish a robust chronology using an integrated dating approach. Using enamel–dentine junction morphology, enamel thickness and comparative morphology, we show that the teeth are unequivocally AMH. Luminescence and uranium-series techniques applied to bone-bearing sediments and speleothems, and coupled uranium-series and electron spin resonance dating of mammalian teeth, place modern humans in Sumatra between 73 and 63 ka. This age is consistent with biostratigraphic estimations, palaeoclimate and sea-level reconstructions, and genetic evidence for a pre-60 ka arrival of AMH into ISEA. Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH, and underscores the importance of reassessing the timing and environmental context of the dispersal of modern humans out of Africa.
K. E. Westaway, et al., "An early modern human presence in Sumatra 73,000–63,000 years ago" Nature(August 9, 2017) (Pay per view) doi:10.1038/nature23452

A newspaper account of the paper's findings with photographs can be found here.


terryt said...

Thanks, very interesting.

"place modern humans in Sumatra between 73 and 63 ka".

At that time the island would have been part of Sundaland.

"Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH"

Interesting that's about the same time as Maju's md-DNA calculations suggest modern human haplotypes distinctively rainforest developed in West Africa.

"the Toba eruption opened up a biogeographic barrier that had confined modern humans to India before then, possibly by thinning out dense forests and shrinking existing hominin populations in the region".

I suspect that the jungles of SE Asia had always limited population numbers. And that goes for southern China as well. After all the panda survived there until very recent times (it's still there, but only just) as did the elephant.

"I'd love to see ancient DNA from the teeth sampled here to see if they had Denisovan admixture"

Wouldn't everyone! I have come round to your idea that Denisovans were spread through most of Eurasia (apart from India?) at an early date.

Have you seen this?

andrew said...

I blogged it at

Matty K said...

Am I right in saying that the only DNA from AMH outside of Africa before 60kya - eg in China and now Sumatra, is from introgression into Neanderthals from the Altai Mts?

andrew said...

@Matty K.

I think so. There is older Neanderthal and Homo Heid and Denisovan ancient DNA with AMH introgression seen only in the Altai Neanderthals at that time depth, but I think that oldest actual AMH ancient DNA anywhere (inside or outside of Africa) is something like 45kya. (Still pretty damn impressive for what its worth).

DDeden said...

This is an aside, but I thought it might be of interest to some:

"The Endogenous gibbon leukemia virus (GALV) & koala retrovirus (KoRV) most likely originated from a cross-species transmission as yet unknown hosts." from Abstract

terryt said...

Oh dear. Old age is catching up. I saw that post!

DDeden said...

I'm starting to check the names of the caves associated with early AMHs or hominin remains for possible paleo-etymologies, I'm not claiming these as factual, but as reasonable interpetations.

est. 80ka
Bhimbetke (Narmada River, central India) Bambatwa-Ebembe(Mbuti: body painting) = ceremoniously painted (cave)wall

est. 72ka
Lida Ajer (Sumatra) may be Lidah Air (Modern Malay) = tongue water

["Sumatra" from Sumbatwa = Xyua + mBatwa = Sieve + Pygmy clan which uses click consonants per Merrit Ruhlen, linguist)]

120ka? (uncertain date)
Mata Menge (Flores) = Mata + menge = eye/point/nipple + dark(mengelap),

50ka? (uncertain date)
Ling Bua (Flores) = Ling + Bua = zero/ceiling(?) + cave (cf. (Malay: gua cave)

est. 60ka
Madjedbembe (Queensland, North Australia)= Image-magic + ebembe(Mbuti: body painting) = ceremoniously glitter-painted(cave)wall

est. 55ka
Booti (island, Northwest Australia) = Birth/beget/mother = Mbo(oldest African YDNA; Mbo in Balinese: mother) + uterine-youth-utility~fertility(?) ~ BaM.buti(Congo Ituri rainforest Pygmy tribe)

I need to find indigenous names of some more caves:

Sulawesi cave with world's oldest painted walls ?
Laos Monkey Cave (Pygmy skull fossil) ?
Borneo (Spirit?) Cave ? 45KA?
Toraja burial caves
Chauvet (France) and other European painted caves with odd or ancient unknown names carried since antiquity.
Southern African cave shelters with artifacts (ochre crayons, etched eggshells like Howieson Poort ~ 65ka

Note: Spirit = haunt(English) = hantu(Malay:white-faced ghost) = Kabuki(Japan:white-faced ghost theatre) = Kaboagi(Piraha tribe, Maici River, Amazon, Brazil: white-faced spirit guide/theatre)

Anyone interested in this project, email me at
My guess is that >15% of all notable caveshelter names were never forgotten completely, since they held communal-ritual-ancestral value in some way.