We are not far from a chaos from which there is no return ● Mammals did not appear in the Jurassic, as thought ● And yet, there could be life on Venus
hurricane seen from outer spacePhoto: NASA / Sciencephoto / Profimedia
We are not far from chaos from which there is no return
Although it has been published for now only on the pre-print arXiv platform, pending the OK from other researchers, the study by some physicists from the University of Porto has already made the rounds of the planet. And no, it’s not really new either, although the approach is somewhat more radical than in the past.
Portuguese researchers have created several computer models to analyze the effects of resource consumption and the effects of human action on the environment. And the results offered by them are not exactly encouraging.
In the most optimistic scenario, Earth will know a point where the level of carbon dioxide in the atmosphere will stabilize. Yes, temperatures will be higher than today, the global population will drop drastically, sea and ocean levels will rise and extreme phenomena will become the norm. But part of the planet’s population will be able to get used to it. And the fact that there is some cyclicality, a stability of atmospheric phenomena, would be an index for a drama of normality. We repeat, this is the optimistic scenario.
In the second scenario, humanity will have influenced the environment and the terrestrial system so much that the weather phenomena on Earth will have a chaotic character. This means that there is no equilibrium left, and temperatures and extreme weather events will fluctuate drastically even from year to year. Practically, no one will be able to predict what will happen next. And what’s even worse is that there are already signs that we’ve kind of started to cross the red line.
What would have been interesting to add to that study is that such anomalies have also been recorded in the past. I am not new to Terra. Often they precede major climate changes, such as entering or exiting an ice age. But now, no, with human action in the middle, it’s harder to tell which direction we’re going.
Mammals would not have appeared in the Jurassic, as thought
The Yanliao biome, a name used to describe several fossiliferous complexes in northern China, some of the richest in the world, has recently provided data that challenges one of the theories that seemed to be nailed down. Namely, the origin of the ancestors of today’s mammals, an origin that would have been identified through the middle Jurassic period, about 160 – 180 million years ago.
At least that’s what a group of researchers from the Institute of Paleontology and Paleoanthropology in China claims in a study published in the journal Earth and Planetary Science Letters. In short, the researchers identified the traces of a former lacustrine environment, from which they recovered numerous fossils belonging to creatures from approximately 160-168 million years ago.
Among the life forms of that period, Chinese paleoanthropologists discovered the fossilized remains of some dinosaurs capable of gliding, the oldest dinosaurs of this kind, several species of salamanders but, most importantly, they brought to light the fossilized remains of some of the first ancestors of today’s mammals, some belonging to the Euharamiyida family.
Uranium-lead dating on 129 zircon crystals recovered at the same site revealed the age mentioned earlier, which places the site’s age in the mid-Jurassic. And then, how do the Chinese rewrite the hypotheses regarding the origin of mammals?
According to the study’s authors, they applied a Bayesian model in which they introduced characteristics of the proto-mammals discovered in northern China, as well as similar traits found in even older life forms that betray a common evolutionary pattern.
The result was that the origin of the ancestors of mammals can be traced back to the end of the Thracian, at least 208 million years ago. It’s not exactly a new idea. Such a hypothesis had been put forward before, but it had been strongly contested. Thus, the scientific world had only two options regarding the emergence of proto-mammals.
The first, which claimed that they appeared in the Jurassic and experienced a rapid diversification. The second, the one originally disputed, and which said that the ancestors of mammals appeared in the Triassic, from which point they experienced a slow evolution until the middle of the Jurassic, when they experienced a strong diversification. From what the Chinese researchers say, it seems that precisely the least likely hypothesis would also be the real one.
And yet, there could be life on Venus
Speaking of hypotheses that are not at the first publication, or even at the first youth we could say, the one related to the existence of life on the planet Venus comes to light again, after it was launched for the first time in the 19th century, and after it has been discussed and re-discussed about every decade.
This time, the information comes not from one study, but from two, published in the journal Astrobiology, respectively PNAS, by a group of Anglo-American researchers from the University of Cardiff, UK, and MIT, USA. And their hypothesis, while by no means new, this time benefits from laboratory tests that had never been done before.
Specifically, the researchers started from the idea that appeared since the 50s of the last century, according to which microbial life could thrive in the Venusian atmosphere. At least on the surface of the planet, at an average temperature of 464 degrees Celsius, it is clear that there cannot be the imperious solvent necessary for the chemistry of life…water. In fact, no liquid is compatible with those temperatures. But the situation is different in the atmosphere of the planet Venus where, by the way, the clouds are made of sulfuric acid.
What the aforementioned specialists bring is the idea that, in the absence of water, sulfuric acid can act as a solvent in what is meant by the equation of life. They have proven this. In short, they put in a container of sulfuric acid, with a concentration of 81 to 98%, all the ingredients that form the basis of DNA and RNA.
Strange as it may seem, adenine, cytosine, guanine, thymine and uracil remained stable for several weeks at a temperature of 18-21 degrees Celsius, the same as that of the Venusian atmosphere. The same happened with purine and pyrimidine, compounds with which some viruses replace adenine. And that means that, at least in theory, life can actually exist there.
But since things don’t stop there, the team of authors also discussed the mass of life forms, namely gravity and the possibility that hypothetical microbial life could remain in the atmosphere without falling into the hell below. And the tests showed again that they can remain indefinitely in the atmosphere, thanks to the gravitational waves there.
In conclusion, yes, we could hope to find some Venusian life forms. But there’s no way they’ll resemble what we know about life on Earth.
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