Politicising Science: Mungo man

  Fake tradition, False conclusion
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On 7 June, the ABC published the following headline:

“New DNA technology confirms Aboriginal people as first Australians”

In practice, the research confirmed nothing of the sort.

Professor David Lambert, from Griffith University, and colleagues, have used new DNA sequencing methods to re-analyse the material from Mungo Man

According to Prof. Lambert:

“The sample from Mungo Man which we retested contained sequences from five different European people, suggesting that these all represent contamination”

“We could not, with better technology, repeat what the original study found and therefore the evidence that Aboriginal people were not the first Australians has no foundation“.

Lambert was accurate. He said ‘the evidence has no foundation’. The ABC falsely generalised that to claim that so-called ‘Aboriginal’ people were ‘definitely first’. You can’t disprove a theory from lack of evidence – you can only prove a theory with evidence. The theory may have lost its foundation but it is in no way disproved.

Source: ABC News

Here is another fake headline, this time from Australian Geographic:

“Aboriginal people were definitely first Australians”

“New DNA sequencing has proven Aboriginal people really were the first to inhabit Australia.

Quoting Lambert again:

“At the same time we re-analysed more than 20 of the other ancient people from Willandra. We were successful in recovering the genomic sequence of ONE of the early inhabitants of Lake Mungo, a man buried very close to the location where Mungo Man was originally interred”.

So no conclusion can be reached from the other 19 samples.

“By going back and reanalysing the samples [plural?] with more advanced technology, we have found compelling support for the argument that Aboriginal Australians were the first inhabitants of Australia”.

Source: Australian Geographic

The sample was tagged as ‘WLH4’. WLH4 could well have been a later inhabitant of Willandra lakes. The presence of WLH4 in no way invalidates the possibility that there could have been an earlier, distinctly different inhabitant.

Lambert’s paper: Ancient mtDNA sequences from the First Australians revisited

The publication in 2001 by Adcock et al. [Adcock GJ, et al. (2001) Proc Natl Acad Sci USA 98(2):537–542] in PNAS reported the recovery of short mtDNA sequences from ancient Australians, including the 42,000-y-old Mungo Man [Willandra Lakes Hominid (WLH3)]. This landmark study in human ancient DNA suggested that an early modern human mitochondrial lineage emerged in Asia and that the theory of modern human origins could no longer be considered solely through the lens of the ‘Out of Africa’ model. To evaluate these claims, we used second generation DNA sequencing and capture methods as well as PCR-based and single-primer extension (SPEX) approaches to reexamine the same four Willandra Lakes and Kow Swamp 8 (KS8) remains studied in the work by Adcock et al. Two of the remains sampled contained no identifiable human DNA (WLH15 and WLH55), whereas the Mungo Man (WLH3) sample contained no Aboriginal Australian DNA. KS8 reveals human mitochondrial sequences that differ from the previously inferred sequence. Instead, we recover a total of five modern European contaminants from Mungo Man (WLH3). We show that the remaining sample (WLH4) contains ∼1.4% human DNA, from which we assembled two complete mitochondrial genomes. One of these was a previously unidentified Aboriginal Australian haplotype belonging to haplogroup S2 that we sequenced to a high coverage. The other was a contaminating modern European mitochondrial haplotype. Although none of the sequences that we recovered matched those reported by Adcock et al., except a contaminant, these findings show the feasibility of obtaining important information from ancient Aboriginal Australian remains.

Source: PNAS

On this day: Mungo Man fossil found – 26 Feb, 1974

Attempts to do further research have been blocked.

Messages from Mungo: Mungo Child

A number of other scientifically significant remains have been discovered at Willandra but never disturbed or studied, in line with the wishes of the area’s Aboriginal custodians. ‘Mungo Child’, as it has become known to scientists, was discovered in 1987 and may be of similar antiquity to Mungo Man. ‘There are no other juvenile skeletons in this 40,000-year age range in the entire Australian and Asian region’, says Dr Michael Westaway, from Griffith University, in Brisbane. ‘The remains of Homo sapiens of this antiquity are very, very rare globally’.

When the top of the juvenile skull was discovered, just a few centimetres of sand were brushed off it before it was reburied. ‘It was never fully excavated’, Harvey says. ‘Some years later, part of the mandible [jaw] became exposed through natural erosion, and confirmed it was clearly an adolescent or child’. Since the mid 1980s, park rangers swiftly rebury any exposed human remains, often covering them with shadecloth to retard erosion.

Source: Australian Geographic