Does the planetary evolution favors life like a man? Study the odds that we are not alone

The model, which increases the decades of old “heavy steps” that the intelligent life was an incredibly incredible event, suggests that it may not have been all so hard or amazing. A team of researchers from Penn State, who led the work, said that the new interpretation of the origin of humanity increases the likelihood of intelligent life elsewhere in space.

“This is a significant shift in the way we are thinking about the history of life,” said Jennifer Macalady, a professor of geoscience in Penn State and a co -author at the magazine, which was published today (February 14) in the journal) Progress of science. “This suggests that the evolution of complex life may be less fortunate, and more about the interaction between life and its environment, by opening the exciting new ways of research in our efforts to understand our origin and our place in space.”

Initially developed by theoretical physicist Brandon Carter in 1983, the “hard steps” model claims that our evolutionary origin was very unlikely due to the time that people needed to develop on Earth over the overall life of the Sun – and the very And the likelihood of being like people outside the country is extremely low.

In a new study, a team of researchers involving astrophysicists and geobiologists claimed that the earth environment was initially uncomfortable for many forms of life, and that the key evolutionary steps became possible only when the global environment reached the “permissive” condition.

For example, the complex life of an animal requires a certain level of oxygen in the atmosphere, so the oxygen of the earth’s atmosphere through photosynthesizing microbes and bacteria was a natural evolutionary step for the planet, which created a window of possibilities for developing newer life forms, explained Dan Mills, postdoctoral researcher from the University in Munich and the leading author at work.

“We claim that an intelligent life may not require a series of happy breaks,” said Mills, who worked at Macalady’s astrobiological laboratory at Penn State as a undergraduate researcher. “People haven’t evolved” early “or” late “in the history of the country, but” on time “when they were in place. Maybe it’s just a matter of time, and maybe other planets are able to achieve these conditions faster than what did, while other planets could last longer. “

The central prediction of “hard steps” theory says that very few, if any, other civilizations exists throughout the universe, because steps such as the origin of life, the development of complex cells and the occurrence of human intelligence are impossible on the basis of Carter’s interpretation of the overall life of the sun amounted to 10 billion year, and Earth’s age of about 5 billion years.

In a new study, researchers suggested that the time of human origin can be explained by the sequential opening of “housing windows” in the history of the country, encouraged by changes in the availability of nutrients, the temperature of the sea surface, the level of ocean salinity and the amount of oxygen in the atmosphere. Given all the interaction factors, they said, the earth has only recently become a hospitable humanity – this is simply a natural result of these conditions in action.

“We imagine that, instead of based our predictions of the life of the Sun, we should use a geological time scale, because it takes the atmosphere and the landscape to change,” said Jason Wright, a professor of astronomy and astrophysics in Penn State and co -author on paper. “These are normal time frames on Earth. If life develops with a planet, then the planetary scanter planetary pace will develop.”

Wright explained that part of the reason that the “hard steps” model overcame that it came from his own astrophysics discipline, which is a default field used to understand the formation of planets and celestial systems. The work is a collaboration between physicists and geobiologists, and each learns from the fields of each other to develop a shade image of how life develops on a planet like Earth.

“This work is the most gentle act of interdisciplinary work,” said Macalady, who also directs the Penn State Astrobiology Research Center. “Our fields were far away and we put them on the same page to ask this question how we came here and are we alone? It was a bay and we built a bridge.”

Researchers said they plan to test their alternative model, including the examination of a unique status of proposed evolutionary “hard steps”. Recommended research projects are listed in current work and include such work as the search for the atmosphere of the planet outside our solar biosignature system, such as the presence of oxygen. The team also suggested testing the request for proposed “heavy steps” to determine how hard they are strenuous by studying university and multiple life forms in certain environmental conditions, such as lower oxygen and temperature levels.

In addition to the proposed projects, the team suggested that the research community should investigate whether innovations are – such as the origin of life, oxygenic photosynthesis, eukaryotic cells, multiple animals, and Homo sapiens – They are truly unique events in the history of the country. Can similar innovations develop independently in the past, but evidence that they have happened are lost for extinction or other factors?

“This new perspective suggests that the appearance of an intelligent life may not still be so long shot,” Wright said. “Instead of a series of incredible events, evolution can be a more predictable process, taking place as global conditions allow. Our frame refers not only to the ground but also other planets, increasing the possibility that life similar to ours could exist elsewhere.”

Another co -author at work is Adam Frank of the University of Rochester. Penn State Astrobiology Research Center, Penn State Exoplanet Center and Posted Worlds, Penn State Extraterrestrial Intelligence Center, NASA –‘s exobiology program and the German research Foundation supported this work.