TEMPO.CO, Chicago - The eruption of the Toba super volcano some 74,000 years ago did not seem to wipe out all living beings during that time. Some mammals, aside from humans, managed to survive the vast quantities of ash raining down on them after the explosion, says Geoffrey Hayes, a researcher from Northwestern University in Chicago.
The new analysis casts doubt on a theory that humans were almost extinct by the fall-out from the eruption. This comes from a pattern in genetic data called a bottleneck, which suggests that a population has rapidly expanded after recently collapsing.
The eruption of the super volcano spewed out tons of ash, plunging the earth into a dark winter of volcanic ash for years. Hayes and his team examined the mitochondrial DNA of 19 mammal species from every continent, comparing genetic diversity in different individuals of the same species, and looking for similar patterns.
The bottleneck showed up in seven of the species, but only coincided with Toba in two: the Siberian roe deer and Chinese black snub-nosed monkey.
Hayes adds that because the volcanic winter would have been most severe around Indonesia where Toba is situated, species in that area should have been more affected. But his analysis shows that some species living near or on the archipelago did not go through a bottleneck.
Hayes says that Toba may have wiped out the human population, yet this small piece of evidence says otherwise,New Scientist reports. Hayes presented his findings at a meeting of the Society for Molecular Biology and Evolution. He intends to examine more animal species as well as the chloroplast of plants that would have been affected by the darkened skies following the massive eruption.
Stanley Ambrose of the University of Illinois in Urbana-Champaign, the first scientist who formulated the Toba theory, says that other species may have different stories to tell. Fossils reveal that macaques and tigers that bottlenecked at that time managed to survive while orangutans became extinct in most parts of Southeast Asia not long after the eruption.
NEWSCIENTIST | MAHARDIKA SATRIA HADI
