Sulfur played a vital role in the history of life on earth a new study says, and the fact that sulfur was abundant in the early earth, meaning plenty of material for microbes to metabolize to serve as fuel for photosynthesis, means that the abundance of sulfur in the early earth played a vital role in the oxygenation of the earth’s atmosphere.
However, because sulfur quickly degrades in an oxidized environment, the sulfur chemistry of early life on earth was “quickly lost to time,” as the article says.
Because sulfur is quickly oxidized in an oxygen-rich environment, and then removed from the atmosphere by precipitation and run-off into the ocean, the sulfur chemistry of early Archean life was phased out and lost to time. However, by understanding the mass independent fractionation process, it should be possible to learn more about the atmosphere of the pre-oxygenated Earth and the conditions in which the first life on Earth lived.
The process behind the mass independent fractionation of sulfur remains uncertain, but the two most popular hypotheses are either photolysis (the breaking apart of molecules) by ultraviolet light from the Sun, or reactions between elemental sulfur. “However, the actual phenomenon, reaction or mechanism is still to be identified,” says Dmitri Babikov, a Professor of Physical Chemistry and Molecular Physics at Marquette University in Milwaukee, Wisconsin.
The article says that sulfur isotopes could serve as potential indicators of environments similar to that of the early earth’s, but that today’s technology is too limited to be of any help in identifying such indicators in potential exoplanets. Let’s hope the Jim Webb telescope is launched soon, for much is yet to be learned about the universe at large.
Apparently a new species of felid has been discovered in Sardinia recently, called the “cat-fox” by locals because of its size and tail, it was known to exist for many years but only recently has it been identified by scientists, it’s very reclusive by nature, being nocturnal and possessing an extremely small population of only 10-16 individuals. Sardinian folklore tells tales of this “cat-fox” sneaking into pastures at night and attacking the udders of ewes and goats. Efforts are underway to protect this mysterious new species of cat, er, “cat-fox.”
If only Sagan were around today to learn of the fascinating insights we have discovered since his untimely death. Since his death we have discovered more than 4,000 exoplanets, we have discovered numerous candidates for harboring extraterrestrial life in our solar system alone (*cough* Europa *cough*), coinciding with that we have discovered that numerous minor planetary bodies have oceans of liquid water inside them, with some (*cough* Europa *cough*) even possessing the right chemical mix for complex life to occur on them, not merely simple life, but complex life, I`d be willing to bet that there are fully fledged animals inside Europa’s oceans.
Sagan would be amazed by what we have discovered since his death. He would be 83 years old today. The work he had done in popularizing science to the masses remains uncontested, he inspired millions of future scientists with his works, he was truly a gift from the gods. Rest in peace, Carl, you have earned it.
On Usenet recently someone brought up the possibility of solar systems forming around Pop III stars even though, being huge, they would’ve lived only a few million years. Giant stars have short lifespans of only a few million years, a few tens of millions of years at most, and I am incredulous that any substantial planetary system could develop around stars with such short lifespans.
Pop III stars were the first stars in the universe, none are around today, and thus they’ve never been directly observed because they are so old. (They’ve been indirectly observed tho, including by means such as detecting supermassive black holes.) One is better off looking for solar systems around main sequence and dwarf stars, especially if one is looking for ones with life in them.
Said poster also brought up that only gas giants could’ve presumably been found orbiting Pop III stars, but I would like to point out that the cores of gas giants are still metallic, and so would’ve required heavy elements for the gas to accrete to, which would’ve existed long after the Pop III stars went supernova, since they would’ve lacked the heavier elements in their makeup necessary for even gas giants to form.
Abstract: Complex projectiles—propulsion via mechanical aid—are considered an important technological innovation, with possible relevance for the successful Out-of-Africa dispersal of our species. Conclusive evidence for the beginning of this technology, however, is lacking from the early Late Pleistocene (ca. 130 to 70 thousand years ago; ka). Given the extremely limited applicability of relatively robust methods for validating stone-tipped projectile use, such as through fracture propagation velocity, converging lines of circumstantial evidence remain the best way to examine early complex projectiles. We assess here suggestions for an early Late Pleistocene origin of complex projectiles in Africa. Results from both previous and present independent approaches suggest a trajectory in which complex projectiles were likely adopted during the early Late Pleistocene in eastern Africa. At Aduma (Middle Awash, Ethiopia), morphometric, hafting, and impact damage patterns in several lithic point assemblages suggest a shift from simple spear technologies (thrusting and/or hand-cast) to complex projectiles. Broadly dated to 80–100 ka, lithic points from later phases of the Aduma succession represent a particularly strong candidate for projectile armatures most comparable to ethnographically known spearthrower darts, lending support for previous suggestions and warranting further investigations.
Notes: This is interesting, very interesting, because it pushes back the date of the invention of the atlatl back to the Middle Paleolithic, long before modern humans spread out of Africa, and also long before the earliest evidence for the atlatl in the archaeological record, which AFAIK is from Aurignacian Europe, it’s also telling because Native Americans lacked the atlatl until the advent of the Archaic period, so either the ancestors of the Native Americans lost the atlatl sometime prior to the peopling of the Americas or the atlatl wasn’t as common as previously believed. The Tasmanians also lacked the spearthrower or atlatl, despite ultimately coming from the same population that left Africa as the rest of us did, while the Australians *did* possess the spearthrower, called the *woomera* there, although it was of recent (Holocene) derivation.
I`m a little late to the party but I’ve seen some hogwash going around about how the new black hole photo taken recently is a “hoax,” citing the fact that the photo is blurry to claim it’s “photoshopped.” Of course the damn photo’s gonna be blurry, it’s a picture of an object over fifty three MILLION light years away, be amazed we even managed to take the photo in the first place. Idiots, I swear. Why would they hoax something as amazing as this? Wouldn’t it be a far greater accomplishment to, you know, *take the damn photo in the first place*?
This reeks of the bullshit about the supposed Apollo Moon landings “hoax” and the same principle applies here as it does there, it would be an infinitely greater achievement to actually land on the Moon as oppose to faking it, sometimes the path of least resistance isn’t always the way to go. People are too pessimistic and paranoid, well there’s my two cents. Make of it what you will.
Homology is the study of shared features between taxonomic clades, such as how all tetrapods, from amphibians to mammals, possess fingers, and is something that can only be explained by evolution. For example, what intelligent designer would give whales fingers and leg bones enveloped inside of a fleshy membrane, complete with shoulders, instead of giving them fish fins, and what intelligent designer would give whales lungs instead of enabling them to filter oxygen through the water like fish do?
These are the hallmarks of evolution, not creation. Evolution explains homology, Creationism doesn’t. It is as the late, and great, eminent Ukrainian evolutionary biologist Theodosius Doubzhansky once said:
Biology only makes sense in the light of evolution.
Homology is just one of many things in modern biology that can only be explained by evolution. Homology is indicative of common descent, not common design, as some Creationists like to claim. No intelligent designer would give whales lungs, after all.
Homology as a science was first devised by the great French anatomist and paleontologist Georges Cuvier himself, widely regarded to be the “Founder of Paleontology”, and who also happened to be a creationist, albeit not a young-earth creationist, he died a quarter of a century before Darwin published his seminal masterpiece On the Origin of Species (1859).
This is the second entry of a series of essays explaining basic evolutionary biology, the first can be found here.