We know that life has taken a long and winding path from the first single-celled organisms to its strange neighborhood with too many sticky substances, but how did life get there in the first place?
Possible answers to the origin of life include the heat and pressure of deep-sea thermal vents, the rapid onset of lightning, and the structure of DNA fallen on clay beds (as boring as it may be, many mythologies talk about humans being created from clay, probably because it’s poetic).
Another possible solution is that life was brought here from space by a comet or asteroid. “Panspermia”, the idea that the Earth has been seeded with life from another world.
It’s a useless idea, because it just says that life can jump from rock to rock and doesn’t explain the genesis of life. However, this is not the only space-centric proposal for the origin of life.
New research from the University of Hawaii provides “compelling evidence” that a key component of life, phosphorus oxoacids, building blocks of chromosomes and essential to life’s ability to self-replicate, comes from space.
Until this research, it was not known how these essential building blocks came into existence. According to this research, the conditions on a comet are ideal for creating oxoacids of phosphorus:
Deadly poisons, phosphine, ice and carbon dioxide, which rush in the dark and are burned and deformed by radiation. That’s a recipe for a delicious stew, right there.
The paper, published in the journal Nature Communications, details an experiment in which the researchers recreated conditions that might be found on a comet.
They made artificial ice in space and exposed it to the same kinds of radiation found outside the warm cover of our atmosphere.
This caused chemical reactions that ended up spitting out exactly what the researchers expected to find:
Phosphorus oxoacids like those that make up chromosomes. The article’s lead author, Andrew Turner, tells us about the experience:
“On Earth, phosphine is lethal to living things, but in mid-space, the exotic chemistry of phosphine can promote unusual chemical reaction pathways to initiate the formation of bioreactive molecules like phosphorus oxoacids, which could possibly trigger the molecular evolution of life as we know it. »
Cornelia Meinert of the University of Nice in France, who collaborated on this work, commented:
“Since comets at least partially contain the remnants of the protoplanetary disk material that formed our solar system, these compounds could be traced to wherever phosphine is available in sufficient quantities in interstellar ices. »
If this is the true origin of life on Earth, it combines many elements of other proposed theories. And that last point would mean that at least some life is extraterrestrial.