Early Life Was Much More Resilient Than We Thought

first_imgStay on target With the climate changing, it’s likely (and observable even now) that a large chunk of the planet’s biodiversity will be gone because of the inability to adapt. That’s tragic, but fairly common in the evolutionary past. When major changes hit — like when some very stubborn apes start in with heavy industry and growth economics — the life that can’t adapt dies.But new research shows that early organisms could survive — and even thrive — with radical changes to the environment.Scientists started by looking at the gap between the very first life forms of any sort, and the last universal common ancestor (LUCA) all currently living organisms can trace their ancestors back to. These events are separated by many hundreds of millions of years, and in that interim, Earth changed A LOT. And that means our earliest ancestors had to keep up — or we wouldn’t be around to ponder the question.“Encountering such environmental variability early on may be necessary to build up the level of complexity needed for LUCA to have the evolutionary potential to continue to diversify and colonize nearly every habitat on Earth over four billion years,” evolutionary biologist at MIT, Greg Fournier, told Astrobiology Magazine.The current best hypotheses for how life formed are centered on RNA. While we know of DNA as the central and all-critical molecule for life, early organisms likely used RNA. It’s more reactive and can both code for traits, and transcribe genetic information, helping proteins get made. RNA is a bit simpler, and easier for simple organisms to use. More complex life, like most organisms that exist today often rely on a system that uses DNA to store genetic material and RNA to retrieve and use it. RNA is also much more susceptible to changes from UV radiation.(via qimono/Pixabay)That’s key to the study, because scientists have suspected that life could have got its first start just under the surface of an Early Earth — pelted by intense UV from a young, violent star. At the same time, this life was also likely able to move into high-radiation environments that could trigger chemical reactions needed for the building blocks of more advanced life.Moreover, while the sun may have been a little bit rowdy with the UV, it kicked out much less heat 4.4 billion years ago. This could have led to many masses of oceanic ice that could have helped amino acids and RNA — two critical components for life — to form. This would have also likely concentrated these organic compounds in the pools and the slush of the early planet.LUCA, however, likely lived in much more temperate climates. Because all life on Earth has genes, we can figure out what traits LUCA had by looking at what all life on Earth has in common. The DNA that makes up the 600-ish genes we suspect LUCA code from proteins that are most stable in more mild climates.“Building on the work of many others, we suggest that life dispersed into and adapted to new environments very early in its history,” study co-author and geobiologist Marjorie Cantine. “Perhaps a rapid establishment of complex environmental and ecological relationships was even necessary for early life to persist.” Watch: Dolphin Leaps Feet Away From Unsuspecting SurferNASA Says 2 Asteroids Will Safely Fly By Earth This Weekend center_img Let us know what you like about Geek by taking our survey.last_img

Leave a Reply

Your email address will not be published. Required fields are marked *