Dental disinfectants from 13,000 years ago
|April 19, 2017||Posted by News under Human evolution, News|
From Megan Gannon at LiveScience:
Archaeologists unearthed the skeletal remains of a person who lived about 13,000 years ago at Riparo Fredian, near Lucca in northern Italy. The person’s two front teeth (or upper central incisors) both had big holes in the surface that reach down to the tooth’s pulp chamber.
Not only was the infection cleaned with a handheld stone tool but it was disinfected.
But the dental work didn’t end there. Inside the tooth cavities, there were traces of bitumen, a tar-like substance that might have been used as an antiseptic or a filling to protect the tooth from getting infected, the researchers said. More.
Our ancestors are getting smarter with each passing decade. A reverse Flynn effect?
Flynn effect (generations’ IQ scores tend to rise under good living conditions):
The “Flynn effect” refers to the observed rise in IQ scores over time, resulting in norms obsolescence. Although the Flynn effect is widely accepted, most approaches to estimating it have relied upon “scorecard” approaches that make estimates of its magnitude and error of measurement controversial and prevent determination of factors that moderate the Flynn effect across different IQ tests. We conducted a meta-analysis to determine the magnitude of the Flynn effect with a higher degree of precision, to determine the error of measurement, and to assess the impact of several moderator variables on the mean effect size. Across 285 studies (N = 14,031) since 1951 with administrations of two intelligence tests with different normative bases, the meta-analytic mean was 2.31, 95% CI [1.99, 2.64], standard score points per decade. The mean effect size for 53 comparisons (N = 3,951) (excluding three atypical studies that inflate the estimates) involving modern (since 1972) Stanford-Binet and Wechsler IQ tests (2.93, 95% CI [2.3, 3.5], IQ points per decade) was comparable to previous estimates of about 3 points per decade, but not consistent with the hypothesis that the Flynn effect is diminishing. For modern tests, study sample (larger increases for validation research samples vs. test standardization samples) and order of administration explained unique variance in the Flynn effect, but age and ability level were not significant moderators. These results supported previous estimates of the Flynn effect and its robustness across different age groups, measures, samples, and levels of performance. (public access)
See also: Stone Age dentistry 14kya (Cleaning of infection but no evidence of ongoing disinfectants)
The search for our earliest ancestors: signals in the noise
Early human religion: A 747 built in the basement with an X-Acto knife
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