As living organisms eat, grow, and self-regenerate, all the while they are slowly dying. Chemically speaking, this is because life is thermodynamically unstable, while its ultimate waste products are in a state of thermal equilibrium. It’s somewhat of a morbid thought, but it’s also one of the characteristics that is common to all forms of life.
Now in a new study, researchers have created a self-replicator that self-assembles while simultaneously being destroyed. The synthetic system may help researchers better understand what separates biological matter from simpler chemical matter, and also how to create synthetic life in the lab.
The researchers, Ignacio Colomer, Sarah Morrow, and Stephen P. Fletcher, at the University of Oxford, have published a paper on the self-replicator in a recent issue of Nature Communications.
To answer the iconic question “Are We Alone?”, scientists around the world are also attempting to understand the origin of life. There are many pieces to the puzzle of how life began and many ways to put them together into a big picture. Some of the pieces are firmly established by the laws of chemistry and physics. Others are conjectures about what Earth was like four billion years ago, based on extrapolations of what we know from observing Earth today. However, there are still major gaps in our knowledge and these are necessarily filled in by best guesses.
We invited talented scientists to discuss their different opinions about the origin of life and the site of life’s origin. Most of them will agree that liquid water was necessary, but if we had a time machine and went back in time, would we find life first in a hydrothermal submarine setting in sea water or a fresh water site associated with emerging land masses?
Biologist David Deamer, a Research Professor of Biomolecular Engineering at the University of California, Santa Cruz, and multi-disciplinary scientist Bruce Damer, Associate Researcher in the Department of Biomolecular Engineering at UC Santa Cruz, will describe their most recent work, which infers that hydrothermal pools are the most plausible site for the origin of life. Both biologists have been collaborating since 2016 on a full conception of the Terrestrial Origin of Life Hypothesis.
Lynn Rothschild, Senior Scientist at NASA’s Ames Research Center and Adjunct Professor of Molecular Biology, Cell Biology, and Biochemistry at Brown University, who is an astrobiologist/ synthetic biologist specializing in molecular approaches to evolution, particularly in microbes and the application of synthetic biology to NASA’s missions, will provide an evolutionary biologist’s perspective on the subject.
“Thus, our data demonstrate the ability of multicellular organisms to survive long-term (tens of thousands of years) cryobiosis under the conditions of natural cryoconservation,” the researchers said in a study published in Doklady Biological Sciences.
“We looked at a group of tiny, green bacteria called Prochlorococcus which is the most abundant photosynthetic organism on Earth, with a global population of around three octillion (~1027) individuals,” says Sasha.
Ten per cent of the oxygen we breathe comes from just one kind of bacteria in the ocean. Now laboratory tests have shown that these bacteria are susceptible to plastic pollution, according to a study published in Communications Biology.
“We found that exposure to chemicals leaching from plastic pollution interfered with the growth, photosynthesis and oxygen production of Prochlorococcus, the ocean’s most abundant photosynthetic bacteria,” says lead author and Macquarie University researcher Dr. Sasha Tetu.
“Now we’d like to explore if plasticpollution is having the same impact on these microbes in the ocean.”
It’s very easy to forget that complex life on Earth almost missed the boat entirely. As the Sun’s luminosity gradually increases, the oceans will boil away, and the planet will no longer be in the habitable zone for life as we know it. Okay, we likely have a billion years before this happens—by which point our species will probably have destroyed itself or moved away from Earth—but Earth itself is 4.5 billion years old or so, and eukaryotic life only started to diversify 800 million or so years ago, at the end of the “boring billion.”
In other words, life seems to have arisen around four billion years ago, shortly after Earth formed, but then a few billion years passed before anything complex evolved. Another few hundred million years of bacteria, algae, and microbes sliding around in the anoxic sludge of the boring billion, and intelligent life might never have evolved at all.
Unraveling the geologic mysteries of the boring billion, and why it ended when it did, is a complex scientific question. Different parts of the earth system, including plate tectonics, the atmosphere, and the biosphere of simple lichens and cyanobacteria interacted to eventually produce the conditions for life to diversify, flourish, and grow more complex. But it is generally accepted that simple cyanobacteria (single-celled organisms that can produce oxygen through photosynthesis) were key players in providing Earth’s atmosphere and oceans with oxygen, which then allowed complex life to flourish.
New research published in Nature Scientific Reports (opens in new window) has found that a hormone produced by plants under stress can be applied to crops to alleviate the damage caused by salty soils. The team of researchers from Western Sydney University and the University of Queensland identified a naturally-occurring chemical in plants that reduces the symptoms of salt stress in plants when applied to soil, enabling the test plants to increase their growth by up to 32 times compared with untreated plants.
Salinity is a huge issue across the world, affecting more than 220 million hectares of the world’s irrigated farming and food-producing land. Salinity occurs when salty irrigation water is repeatedly applied to crops, leading to progressively increasing levels of salt in the soil which reduces crop yields, increases susceptibility to drought and damages soil microbiology. Scientists have long tried to find ways to breed salt-tolerance or develop methods that remove salt, and this new research is promising in its potential ability to reduce the damage in crop plants that results from salt.
“We identified a compound called ACC that occurs naturally in plants when they become stressed by drought, heat or salty conditions,” said Dr. Hongwei Liu, Postdoctoral Fellow in Soil Biology and Genomics at the Hawkesbury Institute for the Environment at Western Sydney University.
Bruce Damer is a living legend and international man of mystery – specifically, the mystery of our cosmos, to which he’s devoted his life to exploring: the origins of life, simulating artificial life in computers, deriving amazing new plans for asteroid mining, and cultivating his ability to receive scientific inspiration from “endotripping” (in which he stimulates his brain’s own release of psychoactive compounds known to increase functional connectivity between brain regions). He’s about to work with Google to adapt his origins of life research to simulated models of the increasingly exciting hot springs origin hypothesis he’s been working on with Dave Deamer of UC Santa Cruz for the last several years. And he’s been traveling around the world experimenting with thermal pools, getting extremely close to actually creating new living systems in situ as evidence of their model. Not to mention his talks with numerous national and private space agencies to take the S.H.E.P.H.E.R.D. asteroid mining scheme into space to kickstart the division and reproduction of our biosphere among/between the stars…
