A new study published in Ecology and Evolution by Henrik Svensmark of DTU Space has shown that the explosion of stars, also known as supernovae, has greatly impacted the diversity of marine life over the past 500 million years.
The fossil record has been extensively studied, revealing significant variations in the diversity of life forms throughout geological history. A fundamental question in evolutionary biology is identifying the processes responsible for these fluctuations.
The new research uncovers a surprising finding: the fluctuation in the number of nearby supernovae closely corresponds to changes in biodiversity of marine genera over the last 500 million years. This correlation becomes apparent when the marine diversity curve is adjusted to account for changes in shallow coastal marine regions, which are significant as they provide habitat for most marine life and offer new opportunities for evolution as they expand or shrink. Thus, alterations in available shallow marine regions play a role in shaping biodiversity.
When we look at something, the different properties of the image are processed in different brain regions. But how does our brain make a coherent image out of such a fragmented representation? A new review by Pieter Roelfsema sheds light on two existing hypotheses in the field.
When we open our eyes, we immediately see what is there. The efficiency of our vision is a remarkable achievement of evolution. The introspective ease with which we perceive our visual surroundings masks the sophisticated machinery in our brain that supports visual perception. The image that we see is rapidly analyzed by a complex hierarchy of cortical and subcortical brain regions.
Neurons in low level brain regions extract basic features such as line orientation, depth and the color of local image elements. They send the information to several mid-level brain areas. Neurons in these areas code for other features, such as motion direction, color and shape fragments.
Donald Hoffman interview on spacetime, consciousness, and how biological fitness conceals reality. We discuss Nima Arkani-Hamed’s Amplituhedron, decorated permutations, evolution, and the unlimited intelligence.
The Amplituhedron is a static, monolithic, geometric object with many dimensions. Its volume codes for amplitudes of particle interactions & its structure codes for locality and unitarity. Decorated permutations are the deepest core from which the Amplituhedron gets its structure. There are no dynamics, they are monoliths as in 2001: A Space Odyssey.
Background. 0:00 Highlights. 6:55 The specific limits of evolution by natural selection. 10:50 Don’s born in a San Antonio Army hospital in 1955 (and his parents’ background) 14:44 As a teenager big question he wanted answered, “Are we just machines?“ 17:23 Don’s early work as a vision researcher; visual systems construct. 20:43 Carlos’s 3-part series on Fitness-Beats-Truth Theorem.
Fitness-Beats-Truth Theorem. 22:29 Clarifications on FBT: Game theory simulations & math proofs. 24:20 What does he mean I can’t see reality? Fitness payoff functions don’t know about the truth… 28:23 Evolution shapes sensory systems to guide adaptive behavior… consider the virtual reality headset 32:45 FBT doesn’t include costs for extra bits of information processing 34:40 Joscha Bach’s “There are no colors in the universe”… though even light itself isn’t fundamental! 36:36 Map-territory relationship 40:27 Infinite regress, Godel’s Incompleteness Theorem 42:27 Erik Hoel’s causal emergence theory 45:40 Don’s take on causality: there are no causal powers within spacetime What’s Beyond Spacetime? 50:50 Nima Arkani-Hamed’s Amplituhedron 53:00 What percentage of physicists would agree spacetime is doomed? 56:00 Amplituhedron a static, monolithic, geometric object with many dimensions… 59:23 Ties to holographic principle, Ads-CFT correspondence 1:03:13 Quantum error correction 1:05:23 James Gates’ adinkra animations linking electromagnetism & electron-like objects The Unlimited Intelligence 1:08:30 Does Don still meditate 3 hours every day? 1:11:30 “We’re here for the ride…” 1:12:27 All my theories are trivial, there’s an unlimited intelligence that transcends 1:14:00 Carlos meanders on meditation 1:15:50 “You can’t know the truth, but you can be the truth” 1:17:43 Explore-Exploit Tradeoff (foraging strategy) 1:19:15 “You’re absolutely knocking on the right doors here”… our 4D spacetime for some reason essential for consciousness 1:21:10 Why this world, with these symbols, this interface? 1:22:20 “My guess, one of the cheaper headsets” Conscious Realism 1:24:40 Precise, mathematical model of consciousness… the end of Cantor’s infinities 1:28:30 Fusions of Consciousness paper… bridges between interactions of conscious agents/Markovian dynamics → decorated permutations → the Amplituhedron → spacetime 1:35:20 In a meta way, did Don choose the highest fitness path for his career? 1:39:10 “Don’t believe my theory, not the final word” 1:41:00 Where to find more of Don’s work 🚩Links to Donald Hoffman & More 🚩 “Do we see reality as it is?” (Ted Talk 2015) • Do we see reality…
“Symmetry Does Not Entail Veridicality” lecture (Hoffman 2017) • Don Hoffman — “Sy…
In this episode, my guest is Oded Rechavi, Ph.D., professor of neurobiology at Tel Aviv University and expert in how genes are inherited, how experiences shape genes and remarkably, how some memories of experiences can be passed via genes to offspring. We discuss his research challenging long-held tenets of genetic inheritance and the relevance of those findings to understanding key biological and psychological processes including metabolism, stress and trauma. He describes the history of the scientific exploration of the “heritability of acquired traits” and how epigenetics and RNA biology can account for some of the passage of certain experience-based memories. He discusses the importance of model organisms in scientific research and describes his work on how stressors and memories can be passed through small RNA molecules to multiple generations of offspring in ways that meaningfully affect their behavior. Nature vs. nurture is a commonly debated theme; Dr. Rechavi’s work represents a fundamental shift in our understanding of that debate, as well as genetic inheritance, brain function and evolution.
A popular and easy method for validating whether or not a chunk of rock is a meteorite, and what kind of meteorite it is, has been inadvertently erasing invaluable information locked inside.
The use of rare-earth magnets such as neodymium erases and overwrites the magnetic record locked inside ferromagnetic minerals in meteorites, scientists from MIT in the US and Paris Cité University in France found. Since many meteorites that fall to Earth have a significant iron content, this means we’re losing important data on the way magnetic fields in space have altered these meteorites over billions of years.
Meteorites provide invaluable records of planetary formation and evolution. Studies of their paleomagnetism have constrained accretion in the protoplanetary disk, the thermal evolution and differentiation of planetesimals, and the history of planetary dynamos.
The evolution of the human eye has long been considered one of biology’s more challenging mysteries, drawing debate over the sequence of steps required to turn rudimentary sensitivity to light into a complex photographic system.
New research suggests some components of vertebrate vision may not have been shaped incrementally as their genes passed down family lines, but were ‘stolen’ from entirely different branches of life.
“At least one innovation that led to the current structure of vertebrate eyes did not occur from stepwise “tinkering” with genes that exist in other animals, but came from introduction of novel DNA from bacteria by horizontal gene transfer,” explains molecular biologist Matt Daugherty from the University of California, San Diego (UCSD) on Twitter.
