How do we know we’re the first form of life in the Universe? Or, better yet, how did we get here? Your guess is as good as mine. But the fact there are many living organisms on our green planet confirms a great deal in my mind. Scientists found that some negative-stranded DNA viruses make an enzyme that can copy RNA — and RNA is a potential precursor to DNA. This suggests there was once a RNA World where elements that look like enzymes that catalyze RNA replication were present. But even before, some scientists have proposed life may have come from outer space — or even still might be coming from outer space.
We could be among the first forms of complicated life to emerge in the universe.
It’s tempting to imagine that we are the pinnacle of evolution, but the reality is that we could be among the first forms of complicated life to emerge in the universe. It’s an unlikely coincidence if we did evolve shortly after the universe became capable of supporting life.
Earth is exceptionally well-suited for life because it has such a diverse range of environments – from freezing ice caps to boiling hydrothermal vents – so it’s reasonable to assume that alien life would also thrive in lots of different conditions.
Alternatively, we could be one of the last.
The evolution of life on Earth was not a random process. It’s been dominated by the physics of our planet — and the laws of chemistry, which are universal. So if we could rewind the tape, what would happen?
There’s a fair chance that life would not emerge at all. And, alternatively, we could be one of the last.
Astrobiologists have been thinking about these questions for decades. They’re trying to understand how easy or hard it is for life to form, and how probable it is that it will evolve into something complex. The answers depend on a host of variables: geography and geology, chemistry and climate. But we’re making progress towards identifying them all.
Nearby supernovas and cosmic rays may have shaped evolution.
Cosmic rays and nearby supernovas might have been crucial to the origin of life on Earth, according to a new study.
It’s well established that stars are crucibles of chemistry, forming elements like carbon and oxygen that are crucial to life. But the role of cosmic radiation in the emergence of life has not been clearly understood. Now researchers at the University of Zurich have shown that irradiation with cosmic rays can lead to self-replicating RNA molecules.
“We were able to demonstrate for the first time that high energy particles could have played a critical role in the evolution of complex molecular systems on primordial Earth,” says Professor Oliver Hunziker, head of the Cosmic Ray Group at Department of Physics, University of Zurich (UZH). “Our research shows that certain biological molecules can not only withstand high-energy particle radiation but may even use it as a driving force for their own replication.”
The evolution of life is a direct result of an evolutionary arms race between us and our viruses – or rather, between our DNA and theirs.
The evolution of life is a direct result of an evolutionary arms race between us and our viruses – or rather, between our DNA and theirs. The genetic material that makes up both you and me is the same as that which encodes the proteins of the flu virus. So, in a sense, we are all just slightly modified viruses.
But there’s more to it than that. We are also, in a very real way, all descended from viruses. The most important genes in all living organisms came from viruses millions of years ago and were passed down to us through every generation since.
It’s now known that some eight per cent of our genome, containing over 1,000 genes, was acquired from viruses during our evolution. What’s more, we can trace their origin back to just two ancient viral invasions: one about half a billion years ago and the other around 200 million years ago.
Is it likely that there is intelligent life somewhere else in the universe? Almost certainly! But not with certainty.
The origin of life is the time when life arose. The most accepted hypothesis, abiogenesis, holds that all known life is descended from a common ancestor or ancestral gene pool.
The study of the origin of life must be conducted within the framework of energy, water, and carbon dioxide on early Earth which was an anoxic (oxygen-free) planet. Carbon dioxide in the atmosphere and dissolved in water, as well as methane and other volatiles, were abundant on early Earth. Water is thought to have been present in large quantities at the surface of early Earth before the emergence of life.
The “RNA world”, which hypothesizes that ribonucleic acid (RNA) was capable both of storing genetic information and catalyzing chemical reactions, is widely regarded as a major step in solving this problem.
It’s unclear when life began in our universe, but certainly not when it will end!
Other scientists think that life may not have originated on Earth at all! They suggest that living organisms arrived on Earth from outer space by means of comets or meteors. These organisms could have been trapped inside crystals or soft rock called clay. However, recent experiments show that when such crystals and clay are exposed to radiation (which exists in space), they become too damaged for life to survive. So maybe we won’t find the answer in space after all!
In a world where we are constantly discovering more and more exoplanets that could potentially harbor life, it is only logical to assume that there is life elsewhere in the universe. By continuing to search for new planets, looking for signs of life on them and identifying other areas to explore, we are seeking answers to some of our questions about the universe.
