This Single-Celled Microbe Can Transform Into a Multicellular Creature

 A recent study has revealed that Haloferax volcanii, a single-celled archaeon thriving in hypersaline environments like the Dead Sea, can morph into a multicellular structure under physical pressure. This remarkable transformation was discovered by researchers led by Theopi Rados at Brandeis University. When placed under pressures of 10 to 100 kPa—similar to underwater conditions—H. volcanii’s soft, flexible outer layer allows it to flatten and then grow into organized clusters of cells resembling tissue.

Over time, these clusters form distinct cell types: flatter, wedge-shaped peripheral cells and taller, scutoid cells in the center, which are also common in curved eukaryotic tissues like the gut and skin. These scutoid structures, long thought to be exclusive to complex eukaryotic organisms, may actually predate them, hinting at ancient origins of multicellularity.

The microbe’s transformation, enabled by its dynamic membrane-like surface rather than a rigid cell wall, suggests that archaea may be highly sensitive to mechanical stimuli. This discovery challenges the notion that complex tissue formation is exclusive to more advanced life forms and underscores how multicellularity might evolve from simple building blocks through environmental pressures.

Strange Bacteria That Can't Live Alone Hint at Early Steps to Complex Life

 A new study shows that s unique group of bacteria known as multicellular magnetotactic bacteria (MMB) may offer insight into the early evolution of complex life. Unlike other bacteria, MMBs are never found living as individual cells—they exist exclusively in tightly bound groups called consortia, where separation leads to cell death. Discovered in a Massachusetts salt marsh, these spherical consortia resemble blastocysts, an early stage in animal embryonic development, hinting at possible evolutionary parallels.

The study led by George Schaible at Montana State University analyzed the metagenomes of 22 MMB consortia and discovered that the cells within are not clones. Instead, they have diverse genetic makeups, allowing for metabolic specialization. Some cells process certain nutrients while others handle different tasks, mirroring a division of labor similar to human societies or body organs. This internal diversity likely helps MMBs adapt to the ever-changing conditions of tidal environments.

The bacteria also use various carbon and energy sources, including reducing sulfate to hydrogen sulfide, a process enhanced by their metabolic cooperation. Scientists believe MMBs could be a modern analog of the transition from single-celled life to multicellularity, making them a fascinating window into the evolution of complex organisms.

Is There DNA Present in Other Parts of Our Solar System?

 On Wednesday, January 29, 2025, The New York Times posted an article titled “Lurking Inside an Asteroid: Life’s Ingredients,” which outlined new discoveries from an asteroid collected by a NASA spacecraft. Researchers studying the debris from an asteroid named Bennu found it contained many important building blocks of life. The collection of this debris was a seven-year process using the Osiris-Rex spacecraft, which launched from Cape Canaveral, FL, in 2016 and returned to Earth in 2023. The spacecraft planned to orbit the asteroid before scientists decided where to scoop the sample from. After examination, 16 of the 20 amino acids used in our cells were found in Bennu’s debris. Additionally, the article shares that the debris contained the five nucleobases involved in protein synthesis through RNA and DNA. Although there is no confirmation of other life, the team of researchers believes that the presence of nucleobases and amino acids could have been an early ancestor of our present-day genes. The researchers do not believe there were any cells on the asteroid but do believe that the atmosphere of Bennu allowed some path toward life before it became too icy. The New York Times article ends with a quote from one of the researchers saying there is a slight chance that life started on the Bennu asteroid. 

Although the article did not directly talk about the genetics of any individual organisms, I think it was interesting to learn about where our genes may have arisen from millions of years ago. Learning that there are amino acids and nucleobases in other parts of our solar system was interesting because it begs the question of whether life exists in places other than Earth. Additionally, I think this article was a good bridge between the biodiversity & evolution and genetics courses because it demonstrates that there is still a lack of answers to some questions in biology, especially regarding the beginning of life and how our genes have evolved into the organisms we encounter today. 

Links:

https://www.nytimes.com/2025/01/29/science/nasa-bennu-asteroid-molecules.html 

https://www.nytimes.com/2016/09/09/science/nasa-launches-osiris-rex-spacecraft-to-retrieve-asteroid-pieces.html 

Thousands of new Viruses Discovered in the Ocean

 

In an article published by Live Science, a new study identified more than 5,000 new virus species in the world’s oceans. The researchers in this study analyzed tens of thousands of water samples from around the globe, hunting for RNA viruses. These viruses are understudied compared with DNA viruses, which use DNA as their genetic material, according to the authors.

The diversity of the newly-discovered viruses was so great that reachers proposed doubling the number of taxonomic groups needed to classify these viruses from the existing five phyla to 10 phyla. As stated by Matthew Sullivan, a professor of microbiology at The Ohio State University, the discovery of an entirely new phylum, Taraviricota, in nearly all of the world’s oceans suggests that they’re ecologically important.

Studies of RNA viruses usually just focused on those that cause diseases, according to Sullivan, however, these make up a very small percentage of all RNA viruses on Earth. For the study, the researchers analyzed 35,000 water samples taken from 121 locations in all five of the world’s oceans. The examined genetic sequences were extracted from plankton, which are common hosts for RNA viruses. They homed in on sequences belonging to RNA viruses by looking for an ancient gene called RdRp, which is found in all RNA viruses but is absent from other viruses and cells. Over 44,000 sequences were identified with this gene.

The RdRp gene is billions of years old and has thus evolved many times. Because the gene’s evolution goes so far back, it was difficult for researchers to determine the evolutionary relationship between the sequences. So the researchers used machine learning to help organize them.

Overall, 5,500 new RNA virus species were identified that fell into the five existing phyla as well as the five newly proposed phyla, which were named Taraviricota, Pomiviricota, Paraxenovirivota, Wamoviricota, and Arctiviricota. Virus species in the Taraviricota phylum appeared to be absent from temperate and tropical waters while viruses in the Arctiviricota phylum are abundant in the Arctic Ocean, according to the researchers.

Understanding how the RdRp gene diverged over time could lead to a better understanding of how early life evolved on Earth.

Related article: https://www.nature.com/articles/sdata201817

Life on Earth: More Closely Related to Extraterrestrial Than We Thought?

Back in Biodiversity and Evolution, I learned a little bit about the potential origins of life on earth.  One common theory was that a comet or meteor crashed into earth carrying the building blocks of life.  It sounded so absurd at the time, and I quickly dismissed the assertion.  Other proposed sources of life on earth were a lightning strike causing a chemical change in certain molecules and genetic material in deep sea vents.  A recent study, however, claims that genetic material could have, in fact, come from comets.  Genetic material, specifically RNA is made of ribose.  Scientists and researchers analyzed an artificial comet containing ices, and their findings point towards the ices containing ribose.  Further, nitrogenous bases and amino acids are commonly found on crashed comets.  So, the discovery of ribose is leading researchers to believe that the components of life did, in fact, come from these comets.  Unfortunately, the study has not yet been validated using real comets.  The researchers used only a simulated comet under simulated conditions, so the next step is to analyze the contents and interactions of macromolecules on a real comet (if possible).

As it turns out, the experiment carried out in April 2016 mentioned above is far from the only experiment of its kind.  In 2012, a similar experiment was carried out, and researchers found 26 amino acids, six of which were classified as diamino acids.  This was important because it could contribute to the construction of peptide nucleic acid, which is the precursor to terrestrial DNA.  

I think that the research on the origins of life are very interesting, but far too hypothetical to place too much trust in.  I find it hard to believe that scientists know enough about space and its environment to accurately create a situation where life could be created.  However, each study makes it seem like a more and more probable cause of life.  Personally, I find it incredible.  To think that our basic components of life came from space is a little bit strange.  Could it mean that life already exists elsewhere in the universe?  Is life on earth really just a variation of an extraterrestrial life form?  These are questions that could be answered as scientists continue their research on the origins of life on earth.  

New Study Outlines 'Water World' Theory of Life's Origins

Over four billion years ago, life began to take form on this nascent Earth. These simple cell life forms 

inhabited a much harsher Earth than us, much wetter with sizzling ultraviolet rays. How did these simple cells become every complexity that inhabits the Earth today? This is a question humans have been asking for centuries.  

A new study from NASA's Jet Propulsion Laboratory and the Icy World's team at NASA's Astrobiology Institute describes how naturally produced electrical energy at the sea floor may have given rise to life. While this hypothesis had already been proposed, (called the submarine alkaline hydrothermal emergence of life) the new report gathers decades of laboratory, field, and theoretical research into one grand idea. 

The new theory, which can be called the 'water world' theory, proclaims life may have began inside warm, gentle springs on the sea floor, back when Earth's oceans covered the entire planet. This idea of hydrothermal vents being the place of the origin of life was first proposed in 1980 by other researchers. The vents they used in their study were called 'black smokers,' bubbling with hot acidic fluids. In contrast, the vents discussed in the water world theory are cooler, gentler, and percolate with alkaline fluids.

(A close-up of chimney structures created in the Icy Worlds lab at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Chimney structures like these can be found on the sea floor, surrounding warm, alkaline hydrothermal vents.)

"Life takes advantage of unbalanced states of the on the planet, which may have been the case billions of years ago at the alkaline hydrothermal vents" said Michael Russel, who first hypothesized life began at alkaline hydrothermal vents back in 1989. Russel claims, "life is the process that resolves these disequilibria." Russell is the lead author of the new water world study, which was published in April's edition of Astrobiology. 

 Russell says the necessary experiments to determine evidence are extremely difficult to design and carry out. For now, the ultimate question of where life originated still remains unanswered.

Find the original article at: http://www.sciencedaily.com/releases/2014/04/140415195712.htm