We have a map of the paths of the most dangerous asteroids for the next thousand years ● We finally know what the first complex animal on Earth looked like ● Pesticides and herbicides, the main reason for the massive decline of birds in Europe

We have a map of the paths of the most dangerous asteroids for the next thousand years

That one day a giant asteroid will hit the Earth is a certainty. It happened and it will 100% happen again. The question is when and, above all, to what extent we will be ready for such a thing. That is, obviously, if we’re still here.

To that end, several organizations around the world are working with NASA to track and calculate the trajectories of asteroids larger than one kilometer in diameter to determine if any of them pose a threat to Earth. Why more than a kilometer? Because such heavenly bodies can cause enormous damage on a potential impact.

The good news is that none will hit Earth in the next hundred years. Maybe even a thousand, but here everything is a little more complicated. This is because it is extremely difficult to estimate the trajectory of a giant asteroid after the 100-year mark.

A simple change in the parameters of the radiation that an asteroid receives from the Sun, or a simple effect of Jupiter’s gravity, can change the trajectory of a celestial body and direct it towards Earth.

At the moment, astronomers have noted only two potential dangers. Asteroid 143651 (diameter 2.3 km), whose orbit is chaotic and cannot be calculated, as well as asteroid 7482 (diameter 1.1 km), which will approach Earth several times in the next millennium. The chance of one of them hitting Earth is slim, but that doesn’t mean we shouldn’t be vigilant.

We finally know what the first complex animal on Earth looked like

Since the careful study of paleontology began in the 18th century, scientists have wondered what the first complex life form was and what it looked like. As time went on and research progressed, only two life forms remained at the top, with no way to determine which one was truly first. Sea sponges, or sponges, have long been thought to be the oldest forms of complex life.

Later, cetaceans, primitive animals related to jellyfish, were proposed to fill the evolutionary gap from the beginning of multicellular life. And the logical conclusion, but given the somewhat more primitive aspect of sponges, extremely simple creatures that didn’t even have a nervous system, would be that sponges came first.

A new study published in the journal Nature by a group of paleontologists from the University of California and the University of Vienna changes the conventional wisdom. In fact, the mentioned scientists compared the genomes of two groups of animals with the genomes of other animals. In doing so, they were able to identify an extremely rare pattern of chromosome rearrangements and fusions, a pattern found in all forms of life today. It seems that he also appeared in sponges.

Crests, in contrast, do not exhibit this genetic pattern. In fact, the authors of the study claim, they are more like non-animals. And two important conclusions follow from this. First, sponges were not the first complex life forms on Earth, but crustaceans. The second, particularly important one, is that evolution is not necessarily a continuous step toward complexity, a fact confirmed by the more complex shape of the Crests compared to the Sponges.

Pesticides and herbicides, the main reason for the massive decline of birds in Europe

The number of wild birds in Europe has decreased over the past half century by more than 550 million specimens. Research into this aspect has shown that pollution and habitat loss will be the main causes of the massive decline in bird numbers.

However, the team, which brought together more than 50 ornithologists, zoologists, biologists and ecologists from 28 European countries, claims that the data was wrong. In a related study recently published in PNAS, researchers argue that the decline was caused, rather, by the widespread use of herbicides and pesticides.

This directly or indirectly led to the disappearance of a huge number of birds. Either by poisoning them, or destroying food sources, or causing medical problems due to exposure to harmful substances. In addition, according to statistics provided by specialists, birds that ate invertebrates and lived near agricultural lands were the most affected.

From 1980 to the present, their number has decreased by almost 57%. During the same period, the number of birds in cities decreased by 28%, and in forests – by 18%.

The conclusion of experts is that intensive agriculture was and is, of course, the main factor in the decline of wild birds. Accelerated urbanization would be only the second important factor in this unfortunate process.

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