Month: March 2020

Usually the main theories about Neanderthal migrations have told us that this group of hominids settled mostly in Europe and then moved to Asia and that the genes they introduced in some populations of Homo sapiens would concern only European and not African populations. However, a new study, published in the journal Cell and conducted by a team of researchers at Princeton, shows that this is not the case: Neanderthal genes may have also “taken root” in African populations, albeit indirectly.

Through a new method of DNA analysis from ancient bones, Princeton researchers have found Neanderthal origins in African and non-African populations. This is the first time that traces of Neanderthals have been found in the Africans, as pointed out by Lu Chen, one of the authors of the study and researcher at the Lewis-Sigler Institute for Integrative Genomics (LSI).

The researchers’ analyses showed that the migration of European populations to Africa introduced Neanderthal genes into African populations.

And it would not have been a direct cross between Neanderthals themselves and African populations: the genes would have come from Homo sapiens populations that already had part of the Neanderthal genome within their DNA. So the theory that Neanderthals would never have frequented Africa still holds.

The migrations of humans who had Neanderthal genes to Africa would have occurred at least 100,000 years ago, before the migrations of African populations to Europe which then led to the modern colonization of Europe and Asia.

“This shows that the remnants of the Neanderthal genome survive in every modern human population studied to date,” stresses Chen.

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See also:

https://www.cell.com/cell/fulltext/S0092-8674(20)30059-3

Fermented soybean foods are associated with a lower risk of death according to a new study published in The BMJ. Soybean foods are widespread in the East, especially in Japan, where they are consumed or consumed in various forms including natto, miso, and the more famous tofu.

A team of Japanese researchers has therefore begun to study the association between all these soy products and the levels of death from any cause, including injuries. Specifically, they analyzed the data of 42,750 men and 50,165 women aged between 45 and 74 years, people from Japan. The data were related to their eating habits, lifestyle, and health status as well as any deaths involving these people who were followed for 15 years.

The researchers discovered a link between increased intake of fermented soybeans and a 10% lower risk of mortality for all causes. More specifically, researchers found a link between people who ate natto more regularly and a lower risk of mortality from cardiovascular disease than those who did not eat this food.

According to the researchers, fermented soy-based foods can boast more fiber, more bioactive components, and more potassium than complementary foods. The same researchers point out that this is, however, only an observational study that cannot establish a direct cause between the consumption of fermented soy foods and the aforementioned risks.

However, researchers say the following in the press release: “In this large prospective study conducted in Japan with a high rate of soy consumption, no significant association was found between total soy product intake and all causes of mortality. On the contrary, a higher intake of fermented soy products (natto and miso) was associated with a lower risk of mortality.”

To understand how plant stems develop and respond to growing weight by thickening and becoming trunks until the plant itself becomes a tree, a team of researchers has produced a new study to understand more about the so-called “vertical proprioception” theory. It is a mechanism that balances the radial growth of the stem first and the stem with the weight gain of the plant.

Researchers from the University of Helsinki, the University of Cambridge and the Finnish Institute of Natural Resources have analyzed the downy birch (Betula pubescens). The researchers confirm that this tree can regulate the radial growth of the stem in relation to the weight that increases with the growth of the plant and this strength itself changes depending on the length of the stem.

In a way, the researchers’ idea is that plants somehow perceive their weight and size by thickening the stem, as Juan Alonso-Serra of the Faculty of Biological and Environmental Sciences of the University of the Finnish capital suggests.n To confirm this, the researchers analyzed the elimäki trees. It is a birch tree with genetic mutations that grows vertically for three months and then collapses following the bending of the stem. The researchers have shown that, unlike normal trees, the elimäki trees are less stable mechanically because they cannot correctly relate their width to their growing weight and this is due to the genetic mutation.

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See also:

https://www.cell.com/current-biology/fulltext/S0960-9822(19)31611-2