The human ancestor assumed an upright posture thanks to supernovas?
How it happened that our ancient ancestors began to move in an upright posture? There are many hypotheses on this subject. Scientists from the University of Kansas have proposed another, rather bold concept, according to which they are responsible for this… supernovae.
Moving in an upright posture is characteristic of humans and other now extinct hominidów. There are many ideas about the development of such a way of moving. One of them mówi that the ancestor of man assumed an upright position after transitioning from an arboreal lifestyle to life on the surface. This happened when he left the forests and started living in grassy areas. Another hypothesis is that bipedalism was achieved by hominids during frequent residence in shallow coastal waters.
It is still not fully known what caused the development of bipedalism in the hominidów, but scientists are still studying the issue. According to scientists at the University of Kansas, the headów reason for the development of bipedalism in our ancestorsów were supernova explosions. The chain of events triggered by them set in motion processes thatóre ultimately led to the fact that Homo sapiens has free hands to build cathedrals, design rockets and take selfies.
The results of the study appeared in the journal „Journal of Geology”.
Supernovae bombarded the Earth with cosmic energy as early as 8 millionóin years ago. They reached their peak of activity about 2.6 million years ago. The avalanche of radiation reaching the Earth caused a huge amount of electrons to appear in the lower layers of the atmosphereów.
The authors of the concept claim that the inducedób ionization probably led to a huge increase in the number of atmospheric discharges. These in turn caused forest firesów around the world, and it is the numerous fires that may have been one of the reasons for theóin, thanks to whichórym ancestors Homo sapiens developed bipedalism.
How? The disappearance of a large part of the forestów forced ancient hominids to adapt to savanna life. This concept of the development of bipedalism is similar to the previous ones, but another reason appears here, whichóra led to movement in an upright posture.
– It is believed that hominins already had some tendency to go bipedalóch legs, even before this event,” said Govówny author Adrian Melott, professor emeritus of physics and astronomy at the University of Kansas. – However, they were mainlyównie adapted to climb trees. When in the place of scorched forestów savannas appeared, they had to travel greater distances between trees. Thus, they improved movement in an upright posture. Standing they could look out over the grasses for predators. It is believed that the transformation of the landscape into savannas contributed to the development of bipedalism, which over time became dominant in the ancestralóin people – added.
Evidence of numerous supernova explosions in the vicinity of Earth (from 100 to 50 parsecsó(w) researchers have found on the seabed. Iron-60 isotopes found underwater indicate that explosions occurred during the period indicated earlieróin supernovae.
– We calculated the ionization of the atmosphere, to której would have occurred if radiation from a supernova explosion located about as far away as the iron-60 sediments indicate had reached Earth, Melott said. – It seems to have increased the ionization of the lower layers of the atmosphere 50-fold. Normally you don’t get ionization of the lower atmosphere because cosmic rays don’t penetrate that far, but the more energetic ones from supernovae may have done so – explained.
According to Melott et alóhe author of the study, Brian Thomas of Washburn University, ionization in the lower atmosphere meant that the abundance of lightning, or lightning strikes, increased significantly.
– When high-energy cosmic rays hit atoms and molecules in the atmosphere they knock electrons out of them. Thus, free electrons unbound to atoms appear. Usually in the process of discharge there is an accumulation of tension between clouds or clouds and the ground surface. But the charge cannot flow because there are not enough electrons nearbyów. Thanks to ionization, this process mógł run much more easily, so there would have been many more lightning strikesów – assessed Melott and added that the likelihood that lightning contributed to the ogólworld fire growthów, is supported by the discovery of złócarbon in soils, whichórych age corresponds to the period of intense bombardment by cosmic rays.
– There is much more charcoal and soot in the world, które began to appear several millionów years ago,” said Melott. – They are everywhere, and no one has any explanation as to why they appeared around the world in róThe Polish group of scientists from different climate zones. Our concept may explain this. We believe that fires have turned forests into savannas. Where once there was a forest, open meadows with bushes growing on them have appeared. In our opinion, this is strongly related to human evolution in pónortheast Africa, in particularólarity in the Great Trenches of Africa, where numerous hominid fossils have been foundów – emphasized.
Melott also acknowledged that no such event had been repeatedóThree are about to be. The closest star, whichóra can explode as a supernova is Betelgeuse. It is located about 652 light years from Earth.