Archive for the ‘evolution’ category

Mar 21, 2023

Lab experiments suggest oxygen in early Earth’s atmosphere may have come from rocks

Posted by in categories: biotech/medical, evolution

A team of geochemists from the Chinese Academy of Sciences, working with colleagues from the University of Hong Kong, Tianjin University and the University of California, has found evidence that suggests much of the oxygen in early Earth’s early atmosphere may have come from rocks. In their study, reported in Proceedings of the National Academy of Sciences, the group conducted lab experiments involving crushing rocks, exposing the results to water and measuring reactive oxygen species that were emitted.

Prior research has shown that Earth experienced what has been called the Great Oxidation Event approximately 2.3 to 2.4 billion years ago. During this time, microbe numbers increased dramatically, as they released during photosynthesis. But prior research has also suggested that a common life ancestor existed before the Great Oxidation Event, which further suggests that there was some amount of oxygen exposure. In this new effort, the researchers suggest that such oxygen could have come from rocks interacting with water.

The work involved crushing samples of quartz and then exposing them to water, which replicates some of the conditions that existed on early Earth prior to the rise of high levels of oxygen in the atmosphere. Adding water to freshly crushed quartz, the researchers found, led to reactions between the water and newly broken crystals. This resulted it the formation of molecular oxygen along with other like hydrogen peroxide. Such species are also known as free radicals and they would have played an important role in the evolution of . This is because by damaging DNA and other cell components, the would have pressured early life to adapt.

Mar 18, 2023

Solving the paradox of how animals managed to evolve with bright colors without being eaten

Posted by in categories: evolution, food

A trio of evolutionary biologists, two with Carleton University, the other with Seoul National University, has apparently solved the paradox of aposematism—how animals managed to evolve with bright colors to warn predators of their toxic nature. In their paper study, published in the journal Science, Karl Loeffler-Henry, Changku Kang and Thomas Sherratt, conducted an analysis of the family tree of over 1,000 frog, salamander and newt species.

For many years, have puzzled over the seeming paradox of aposematism, in which such as frogs develop to warn potential predators that eating them will make them sick or even kill them. How could such colors have evolved? Animals that stand out tend to be the first caught and eaten, preventing the evolution of even brighter colors from occurring. In this new effort, the research team set out to solve this riddle.

The work involved analyzing the of 1,100 species of frogs, salamanders and newts, looking for evidence of evolution of aposematism in a new way—by breaking them down into more categories than previous efforts—five instead of two: conspicuous, cryptic, partially conspicuous, fully conspicuous and polymorphic.

Mar 15, 2023

Fundamental constants: Is the universe fine-tuned for life?

Posted by in categories: alien life, evolution, information science, particle physics

Imagine a universe with extremely strong gravity. Stars would be able to form from very little material. They would be smaller than in our universe and live for a much shorter amount of time. But could life evolve there? It took human life billions of years to evolve on Earth under the pleasantly warm rays from the Sun after all.

Now imagine a with extremely weak gravity. Its matter would struggle to clump together to form stars, planets and—ultimately—living beings. It seems we are pretty lucky to have gravity that is just right for life in our universe.

This isn’t just the case for gravity. The values of many forces and in the universe, represented by some 30 so-called fundamental constants, all seem to line up perfectly to enable the evolution of intelligent life. But there’s no theory explaining what values the constants should have—we just have to measure them and plug their numbers into our equations to accurately describe the cosmos.

Mar 15, 2023

Imagination makes us human—this unique ability to envision what doesn’t exist has a long evolutionary history

Posted by in categories: evolution, neuroscience

You can easily picture yourself riding a bicycle across the sky even though that’s not something that can actually happen. You can envision yourself doing something you’ve never done before—like water skiing—and maybe even imagine a better way to do it than anyone else.

Imagination involves creating a mental image of something that is not present for your senses to detect, or even something that isn’t out there in reality somewhere. Imagination is one of the key abilities that make us human. But where did it come from?

I’m a neuroscientist who studies how children acquire . I’m especially interested in the neurological mechanisms of imagination. Once we identify what brain structures and connections are necessary to mentally construct new objects and scenes, scientists like me can look back over the course of evolution to see when these emerged—and potentially gave birth to the first kinds of imagination.

Mar 15, 2023

Sniper2L is a high-fidelity Cas9 variant with high activity Chemical Biology

Posted by in categories: biological, chemistry, evolution

Kim et al. used directed evolution methods to identify a high-fidelity SpCas9 variant, Sniper2L, which exhibits high general activity but maintains high specificity at a large number of target sites.

Mar 11, 2023

Scientists May Have Found Evidence of Earth’s “Inner Inner” Core

Posted by in category: evolution

The inner workings of our planet are getting weirder.

For generations, scientists have probed the structure and composition of the planet using seismic wave studies. This consists of measuring shock waves caused by earthquakes as they penetrate and pass through the Earth’s core region. By noting differences in speed (a process known as anisotropy), scientists can determine which regions are denser than others. These studies have led to the predominant geological model that incorporates four distinct layers: a crust and a mantle (composed largely of silicate minerals) and an outer core and inner core composed of nickel-iron.

According to seismologists from The Australian National University (ANU), data obtained in a recent study has shed new light on the deepest parts of Earth’s inner core. In a paper that appeared in Nature Communications, the team reports finding evidence for another distinct layer (a solid metal ball) in the center of Earth’s inner core — an “innermost inner core.” These findings could shed new light on the evolution of our planet and lead to revised geological models of Earth that include five distinct layers instead of the traditional four.

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Mar 9, 2023

How Do Supermassive Black Holes Form? Study Reveals Huge Galaxy Mergers During Cosmic Noon Play an Important Role in This Celestial Formation

Posted by in categories: cosmology, evolution

The cosmos is full of mysteries, one of which is the existence of supermassive black holes. Though much effort has been granted to these celestial mysteries, the evolution and formation of such supermassive black holes are quite hard to explain.

Supermassive Black Holes

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Mar 8, 2023

Does God emerge from Boltzmann Brains in the fabric of reality?

Posted by in categories: evolution, neuroscience, quantum physics

The concept of Boltzmann Brain — a self-aware entity that emerges from random fluctuations in the fabric of reality— is intriguing. Perhaps God emerges from the evolution of a cosmic society of Boltzmann Brains?

I am referring to a generic “fabric of reality” but the concept can be formulated more precisely. For example, imagine a conscious, thinking being arising from random quantum fluctuations in the vacuum.

In the delightful “The Gravity Mine” short story, Stephen Baxter imagines the birth of a Boltzmann Brain:

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Mar 8, 2023

Does Evolution Progress In A Straight Line?

Posted by in category: evolution

However, this picture, which depicts the evolution of man, may actually pose a danger to our general understanding of how evolution plays out on the planet. One might interpret the picture as: Evolution is a unidirectional, progressive process for the betterment of species. This, in fact could not be farther from the truth.

So, what is evolution exactly?

Mar 7, 2023

Life may not have been possible on Earth without Jupiter

Posted by in categories: alien life, evolution

New simulations paint a picture of our solar system resembling an ornate clock. “Throw more gears into the mix and it all breaks.”

A new experiment shed new light on the role Jupiter has played in the evolution of life on Earth. In a series of simulations, scientists showed that an Earth-like planet orbiting between Mars and Jupiter would be able to alter Earth’s orbit and push it out of the solar system.

Such an event would extricate Earth from its life support system, the Sun, and would therefore wipe out all life on our planet.

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