Short Stature evolved twice on Flores Island

A Report (Evolutionary history and adaptation of a human pygmy population of Flores Island, Indonesia by Serena Tucci et al. Science 03 Aug 2018, Vol. 361, Issue 6401, pp. 511-516.DOI: 10.1126/science.aar8486) tells us that the pygmy-sized Hobbits of Flores island evolved their own short stature independently from the small-sized Homo sapiens that live nowadays in Flores (pygmies).

The background is (quote from the magazine):

"The genetics of human short stature
Flores Island in Indonesia has a long history of hominin occupation, including by the extinct Homo floresiensis and a more recent settlement by modern humans. Furthermore, Flores has an extant population of pygmy humans, and H. floresiensis exhibited a diminutive adult size relative to other hominins. Tucci et al. examined genetic variation among 32 individuals, including 10 sequenced genomes, from a population of pygmies living close to the cave where H. floresiensis remains were discovered. These individuals exhibit signatures of polygenic selection explaining the short stature and have genomic content from both Neanderthals and Denisovans, but no additional archaic lineages. Thus, restricted height is under selection at this location and has evolved independently at least twice in hominins."

Twice because it evolved once in Pygmies in Flores and again (or rather before) in the H. floresiensis.

The Abstract tells us the following:

"Flores Island, Indonesia, was inhabited by the small-bodied hominin species Homo floresiensis, which has an unknown evolutionary relationship to modern humans. This island is also home to an extant human pygmy population. Here we describe genome-scale single-nucleotide polymorphism data and whole-genome sequences from a contemporary human pygmy population living on Flores near the cave where H. floresiensis was found. The genomes of Flores pygmies reveal a complex history of admixture with Denisovans and Neanderthals but no evidence for gene flow with other archaic hominins. Modern individuals bear the signatures of recent positive selection encompassing the FADS (fatty acid desaturase) gene cluster, likely related to diet, and polygenic selection acting on standing variation that contributed to their short-stature phenotype. Thus, multiple independent instances of hominin insular dwarfism occurred on Flores."

So the pygmy population that is now living on the island has Denisovan and Neanderthal admixture -but no additional archaic lineages. The latter is interesting. Maybe this has been concluded as the only genetic components are that of Denisovans, H. sapiens and Neanderthals.

But, as a BBC News article points out today: "Unfortunately, the wet and tropical conditions on Flores mean that all efforts to isolate hobbit DNA have so far failed. Dr Serena Tucci told the BBC: "Like many other scientists, it is my dream to find ancient DNA from the Hobbit. No DNA was recovered in the original Hobbit fossils, but DNA methods have improved markedly in the last few years.".

So no genetic comparison was made between both short statured groups.

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