Posts tagged evolution
In the “War of the Worlds” by Herbert Wells Martian invaders were defeated by the common cold, which none of the sides took into account. Could something similar happen to the astronauts who will land on Mars? What if the first extraterrestrial life form humans will come into contact with will be viruses? These issues are posed in the journal Astrobiology by Dale Griffin.
Biologists do not consider viruses living beings. They are smaller than bacteria and cannot reproduce themselves: that is why to survive they need to invade a cell and use its genetic tools. Nevertheless, it is viruses that (more…)
For 80 years now we are told that the first self-replicating molecules appeared in the primordial soup in the Earth’s shallow waters, which happened 4 billion years ago. This “soup” was composed of amino-acids, polypeptides, and nitrogenous bases of nucleotides formed as a result of electrical charges, high heat and cosmic radiation.
However, the experiments to replicate similar processes have given mixed results: the basic monomers began to form substances that prevented the expected complexity to exist in this “soup” of polymers.
Later, the problem seemed to have been simplified by the “RNA world” hypothesis, but the probability of spontaneous formation of RNA, which wouldpossess catalytic properties, is very low. It is estimated that four billion years (more…)
Scientists at the University of Sheffield claim to have made a fascinating discovery, which proves the existence of extraterrestrial life.
These are images of a body that was found in the stratosphere, recorded with an electron microscope. The body was found by a scientific balloon at an altitude of 27 kilometers from the Earth’s surface and this, according to the scientists, proves that it cannot have originated from our planet. These microbes have probably come from somewhere else…
“Most would suggest that these particles simply have drifted to the stratosphere from Earth. Yet, it is commonly accepted that an organism of this size is impossible to reach an altitude of 27 km. The only exception is a violent volcanic eruption, but nothing like that was recorded during the three years of our research,” said Milton Wainwright, Professor of Molecular Biology at the University. (more…)
Scientists believe that the defining moment in human evolution could be an asteroid that crashed into the North America, in a place not far from Quebec, 12,900 years ago. The collision resulted in the establishment of a cooler and drier climate on the planet, which led to the birth of agriculture.
In North America, this incident led to the extinction of large animals, including giant sloths, camels, saber-toothed tigers and mastodons. This forced the Americans, who were (more…)
On the Red Planet there could have been more favorable conditions for the emergence of life than on Earth, claim scientists. According to them, one of the meteorites from Mars brought to Earth molybdenum and boron which are necessary for the development of organisms.
This was stated by Prof. Steven Benner, a geochemist of the American Foundation for Applied Molecular Evolution, at the Goldschmidt annual conference. According to him, oxidized minerals such as molybdenum oxide have the crucial role in the origin of life.
Benner was quoted by PhysOrg as saying: “Furthermore, recent studies have shown that conditions, suitable for the emergence of life, might still exist on Mars”. (more…)