Planetary scientist, astrobiologist working on life-rock interactions on Earth, and applications for space exploration. Founder of Space Biosystems Lab.
Davis, California
Joined April 2018
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Dragos G. Zaharescu, Ph.D. retweeted
Scientists from across the globe are calling on MIT to review its decision to terminate the tenure of David Sabatini after a jury verdict vindicated the ousted scientist and rebuked #MeToo era claims from a former colleague. trib.al/i0W69kW
A perspective worth considering when one thinks of life -as we know it
Mitochondria are alive.
They carry their own genomes and express their own genes within their lumens, an internal pocket of watery space, using biomolecules distinct from the cell’s nucleus. Mitochondria also replicate and divide through binary fission, much like bacteria. If one considers bacteria as living entities — and all biologists seem to — then it is impossible to explain why mitochondria are not.
From a thermodynamic perspective, mitochondria take in low-entropy inputs from their host cell, such as glucose or fatty acids, and expel high-entropy outputs, including carbon dioxide and water. Mitochondria also pump out protons through their inner membrane to maintain an out-of-equilibrium thermodynamic balance, using the resulting gradient to produce the ATP molecules that fuel cellular functions, from DNA replication to protein synthesis.
From the molecular biologist’s perspective, a mitochondrion’s role is not limited to simple energy generation, either. Mitochondria also process information and interact with their environment, much like a human cell. They monitor steroid hormones, oxidative stress, heat, ATP levels, secondary metabolites, and many more molecules floating through their environment, the cell’s cytoplasm. Mitochondria then use this information to precisely control cellular functions. For example, when a virus invades a cell, the mitochondria are critical in sensing the intrusion and signaling a host cell to undergo programmed cell death to halt its spread.
And finally, mitochondria grow and reproduce in a manner distinct from the host’s replication process. Mitochondria independently copy their circular genomes, known as mitochondrial DNA, and divide through binary fission. Notably, mitochondrial replication has several distinct properties from those observed during human cellular replication. Mitochondrial DNA mutates 100-1,000 times faster than the human genome and these mutations can significantly alter a mitochondrion’s fitness, thereby changing the fitness of its host cell. Mitochondria are thus agents of — and subject to — the forces of evolution.
Despite all this evidence, the main case made against mitochondria being alive is that they do not perform all of these functions independently, as they must be embedded within the cytoplasm of a host cell to function. However, such an argument is logically inconsistent because, by this same logic, most organisms on Earth would not be considered “living.” After all, nothing in biology lives in isolation from its environment.
Read the full essay by Liyam Chitayat: asimov.press/p/mitochondria
Extraordinary work by extraordinary people!
Out today in @nature.com: our review on how single cells evolve into multicellular organisms, with Ozan Bozdag, @kai_tong_mc25, Peter Yunker, and Matt Herron.
rdcu.be/9ZuiKow9twKa
For an overview, check out the video below.
Congeatulations to the Chemistry team! Randomness in the chemical world produces both, left- and right- oriented molecules. Life machines like enzymes act like locks that only fit a specific molecular shape, and they operate in highly interconnected chain reactions.
Kenso Soai – awarded the 2026 #NobelPrize in Chemistry – designed the first chemical reaction in which only one of the potential mirror images was formed. Other than life itself, no one had ever achieved this feat. The Soai reaction is one of the most spectacular chemical experiments ever conducted.
Life is a mixture of left and right:
• Sugars: The ribose sugars that build DNA and RNA (information substrate) are almost exclusively right-handed (D-form).
• Amino Acids (information products): The amino acids that build proteins are almost exclusively left-handed (L-form).
Celebrating science is celebrating advancements of civilization.
The 2026 #NobelPrize laureates in physiology or medicine have laid the foundation of a new era in neuroscience.
Using optogenetics, researchers have been able to reveal neural circuits governing specific memories, feelings, and behaviours relevant for neurological and psychiatric disorders. In clinical medicine, researchers are using the method in attempts to restore sight in people with visual impairment.
Optogenetics has fundamentally altered our understanding of the brain. Every day brings new discoveries, helping to solve one of humanity’s great mysteries: how our incredible brain works.
Dragos G. Zaharescu, Ph.D. retweeted
Peter Hegemann and Georg Nagel – awarded the 2026 medicine prize – discovered a remarkable protein, channelrhodopsin, in a single-celled alga.
Hegemann wondered how Chlamydomonas, a single-celled alga, is able to swim towards a light source. In the early 2000s, he and Georg Nagel discovered channelrhodopsin, an algal protein with unique properties, found on the surface of the cell. When it is illuminated by blue light, a channel opens through the protein. Charged ions then flow into the cell, creating an electrical impulse. They found that regardless of which cell they put the protein in, those cells became light sensitive.
#NobelPrize
This is a fundamental question to ask within every university. It's down to: ARE WE DISCOVERING HOW REALITY WORKS, OR WE ARE INFLATING ADMINISTRATIVE PROCEDURES ?..
Dragos G. Zaharescu, Ph.D. retweeted
Thrilled that #paper2agent is published in @nature today!
Scientific knowledge is traditionally stored in passive papers. Paper2Agent transforms papers into virtual authors that answer questions, apply its methods and collaborate w/ other paper agents to make new discoveries 🧵
Dragos G. Zaharescu, Ph.D. retweeted
Wow…Roland Fryer and @BillAckman have created a $1 million prize for academic truth-telling, the Carob Trust Prize for Academic Courage.
“The prize awards $1 million each to as many as five social scientists a year who have demonstrated intellectual independence, published findings that were attacked rather than answered, and been validated by the evidence—despite the professional cost. The selection criteria are designed to distinguish courage from contrarianism: Nominees must show a sustained commitment to following logic and evidence regardless of pressure, a willingness to ask questions others avoid, and work that has shifted academic debate, public discourse or policy—often despite being misread, mischaracterized or vilified at the time of publication.”
Robots that build robots is just the beginning of a future where humans free themselves from factory lines.
Today, we launched the world’s first automated production line for advanced general‑purpose humanoid robots, using robots to mass‑produce robots, autonomously.
This was uncharted territory, and we solved it from scratch. The commissioning of our production line means humanoid robots are now ready to scale up and step into the real world.
What touched my heartstrings most was watching our very first advanced general‑purpose humanoid robot complete assembly and walk off the line on its own. To me, this is not just about a smarter tool or a commodity. I hope it gains true generalization ability to take on dangerous, repetitive, or undesirable tasks, and ultimately make life better. Perhaps one day, robots may become our companions, friends, or part of family.
Grateful to every colleague on this momumental mission. And a warm welcome to IRON!
There will come a time when science will be done by humand, and written by AI. And that is rather soon.
