TUM: Hints of supernova iron in bacteria microfossils

[MargaritaMc]

Technische Universität München

Researchers find hints of supernova iron in bacteria microfossils:
First biological evidence of a supernova.

In fossil remnants of iron-loving bacteria, researchers of the Cluster of Excellence Origin and Structure of the Universe at the Technische Universitaet Muenchen (TUM), found a radioactive iron isotope that they trace back to a supernova in our cosmic neighborhood. This is the first proven biological signature of a starburst on our earth. The age determination of the deep-drill core from the Pacific Ocean showed that the supernova must have occurred about 2.2 million years ago, roughly around the time when the modern human developed.


In fossil remnants of iron-loving bacteria, researchers of the Cluster of Excellence Origin and Structure of the Universe at the Technische Universitaet Muenchen (TUM), found a radioactive iron isotope that they trace back to a supernova in our cosmic neighborhood. This is the first proven biological signature of a starburst on our earth. The age determination of the deep-drill core from the Pacific Ocean showed that the supernova must have occurred about 2.2 million years ago, roughly around the time when the modern human developed.

Most of the chemical elements have their origin in core collapse supernovae. When a star ends its life in a gigantic starburst, it throws most of its mass into space. The radioactive iron isotope Fe-60 is produced almost exclusively in such supernovae. Because its half-life of 2.62 million years is short compared to the age of our solar system, no supernova iron should be present on Earth. Therefore, any discovery of Fe-60 on Earth would indicate a supernova in our cosmic neighborhood.

In the year 2004, Fe-60 was discovered on Earth for the first time in a ferromanganese crust obtained from the floor of the equatorial Pacific Ocean. Its geological dating puts the event around 2.2 million years ago.

So-called magnetotactic bacteria live within the sediments of the Earth’s oceans, close to the water-sediment interface. They make within their cells hundreds of tiny crystals of magnetite (Fe3O4), each approximately 80 nanometers in diameter. The magnetotactic bacteria obtain the iron from atmospheric dust that enters the ocean. Nuclear astrophysicist Shawn Bishop from the Technische Universitaet Muenchen conjectured, therefore, that Fe-60 should also reside within those magnetite crystals produced by magnetotactic bacteria extant at the time of the supernova interaction with our planet. These bacterially produced crystals, when found in sediments long after their host bacteria have died, are called “magnetofossils.”

Shawn Bishop and his colleagues analyzed parts of a Pacific Ocean sediment core obtained from the Ocean Drilling Program, dating between about 1.7 million and 3.3 million years ago. They took sediment samples corresponding to intervals of about 100,000 years and treated them chemically to selectively dissolve the magnetofossils – thereby extracting any Fe-60 they might contain.

Finally, using the ultra sensitive accelerator mass spectrometry system at the Maier Leibnitz Laboratory in Garching, Munich, they found a tantalizing hint of Iron-60 atoms occurring around 2.2 million years ago, which matches the expected time from the ferromanganese study. “It seems reasonable to suppose that the apparent signal of Fe-60 could be remains of magnetite chains formed by bacteria on the sea floor as a starburst showered on them from the atmosphere”, Shawn Bishop says. He and his team are now preparing to analyze a second sediment drill core, containing upwards of 10 times the amount of material as the first drill core, to see if it also holds the Fe-60 signal and, if it does, to map out the shape of the signal as a function of time.

[Beyond]

Well that's just simply amazing!!

[neufer]

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What if this supernova caused critical mutations to our DNA that led to Homo habilis:

<<Homo habilis lived from approximately 2.33 to 1.4 million years ago, during the Gelasian Pleistocene period. H. habilis was short and had disproportionately long arms compared to modern humans; however, it had a less protruding face than the australopithecines from which it is thought to have descended. H. habilis had a cranial capacity slightly less than half of the size of modern humans. Despite the ape-like morphology of the bodies, H. habilis remains are often accompanied by primitive stone tools (e.g. Olduvai Gorge, Tanzania and Lake Turkana, Kenya).>>

. http://asterisk.apod.com/viewtopic.php? ... 43#p143043

[b][color=#FF0000]The faint pulsar PSR B1929+10 captured by the unrivalled sensitivity of ESAs XMM-Newton orbiting X-ray observatory. It is speeding through space in the direction of the arrow at a speed of 177 kilometres per second. At this speed, the pulsar leaves a trail of X-ray emitting electron plasma stretching across space. Credit: Image: Werner Becker / MPI for Extraterrestrial Physics[/color][/b]

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Zeta Oph: Runaway Star

I don't see a [Super Nova Remnant] anywhere nearby, and I suppose it could be obscured by denser dust in another part of the nebulosity.

After ~40,000 years there is not much left of a supernova remnant to observe and we would likely be inside of any remnant this close. One must look rather for pulsars.

<<ζ Ophiuchi is moving through space with a peculiar velocity of 30 km/s. Based upon the age and direction of motion of this star, it is a member of the Upper Scorpius sub-group of the Scorpius-Centaurus Association of stars that share a common origin and space velocity. Such runaway stars may be ejected by dynamic interactions between three or four stars. However, in this case the star may be a former component of a binary star system in which the more massive primary was destroyed in a Type II supernova explosion. The pulsar PSR B1929+10 may be the leftover remnant of this supernova, as it too was ejected from the association with a velocity vector that fits the scenario.>>

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<<The Scorpius-Centaurus Association (sometimes called Sco-Cen or Sco OB2) is the nearest OB Association to the Sun. This stellar association is composed of three subgroups (Upper Scorpius, Upper Centaurus-Lupus, and Lower Centaurus-Crux), whose mean distances range from 380 to 470 light years.

Many of the bright stars in the constellations Scorpius, Lupus, Centaurus, and Crux are members of the Sco-Cen association, including Antares (the most massive member of Upper Scorpius), and most of the stars in the Southern Cross. The Sco-Cen OB association appears to be the most pronounced part of a large complex of recent (<20 million years) and ongoing star-formation. The complex contains several star-forming molecular clouds in Sco-Cen's immediate vicinity—the Rho Oph, Pipe Nebula, Barnard 68, Chamaeleon, Lupus, Corona Australis, and Coalsack cloud complexes (all at distances of ~120-200 parsecs), and several less populous, young stellar groups on the periphery of Sco-Cen, including the ~3-5 million-year-old epsilon Cha group, ~7 million-year-old eta Chamaeleontis cluster (also called Mamajek 1), ~8 million-year-old TW Hydrae association, ~12 million-year-old Beta Pictoris moving group, and possibly the ~30-50 million-year-old IC 2602 open cluster.

The stellar members of the Sco-Cen association have convergent proper motions of approximately 0.02-0.04 arcseconds per year, indicative that the stars have nearly parallel velocity vectors, moving at about 20 km/s with respect to the Sun. The dispersion of the velocities within the subgroups are only of order 1–2 km/s, and the group is most likely gravitationally unbound. Several supernovae have exploded in Sco-Cen over the past 15 million years, leaving a network of expanding gas superbubbles around the group, including the Loop I Bubble. To explain the presence of radioactive ⁶⁰Fe in deep ocean ferromanganese crusts, it has been hypothesized that a nearby supernova, possibly a member of Sco-Cen, exploded in the Sun's vicinity roughly 3 million years ago.>>

[MargaritaMc]

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What if this supernova caused critical mutations to our DNA that led to Homo habilis:

This is an interesting idea, Art. The significant fact about brain size is less the comparison with that of Homo sapiens than that the brain size of H. habilis was one-third larger than the various Australopithicus species from which it is presumed to have evolved.

I'd be interested to read more of your thinking about the possible connection between this development and these supernova indications.

Margarita

[neufer]

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What if this supernova caused critical mutations to our DNA that led to Homo habilis:

This is an interesting idea, Art. The significant fact about brain size is less the comparison with that of Homo sapiens than that the brain size of H. habilis was one-third larger than the various Australopithicus species from which it is presumed to have evolved.

I'd be interested to read more of your thinking about the possible connection between this development and these supernova indications.

Early hominins couldn't have heard modern speech
by Colin Barras, New Scientist, 13 May 2013

<<Our australopith ancestors heard their world differently from modern humans.

Rolf Quam at Binghamton University in New York State and colleagues have discovered rare middle ear bones from two extinct southern African hominins – Australopithecus africanus and Paranthropus robustus. A combination of ape-like and human-like features in the bones indicate some australopiths lacked sensitivity to the midrange frequencies that modern humans use for speech. "Anthropologists are in general agreement that these early hominins likely did not possess spoken language," says Quam – the new findings back that claim.

His team now plans to use CT scans of the fossils and 3D virtual reconstruction of the ear anatomy to work out more precisely what the world sounded like to our distant ancestors.>>

[MargaritaMc]

Early hominins couldn't have heard modern speech
by Colin Barras, New Scientist, 13 May 2013

<<Our australopith ancestors heard their world differently from modern humans.

Rolf Quam at Binghamton University in New York State and colleagues have discovered rare middle ear bones from two extinct southern African hominins – Australopithecus africanus and Paranthropus robustus. A combination of ape-like and human-like features in the bones indicate some australopiths lacked sensitivity to the midrange frequencies that modern humans use for speech. "Anthropologists are in general agreement that these early hominins likely did not possess spoken language," says Quam – the new findings back that claim.

His team now plans to use CT scans of the fossils and 3D virtual reconstruction of the ear anatomy to work out more precisely what the world sounded like to our distant ancestors.>>

Very interesting!
Presumably you are you suggesting the possibility that the SN under discussion might have influenced this genetic mutation?

Recently published paper indicates discovery could yield important clues on origins of humankind
Binghamton University via EurekaAlert 13 May 2013

BINGHAMTON, NY– A new study, led by a Binghamton University anthropologist and published this week by the National Academy of Sciences, could shed new light on the earliest existence of humans. The study analyzed the tiny ear bones, the malleus, incus and stapes, from two species of early human ancestor in South Africa. The ear ossicles are the smallest bones in the human body and are among the rarest of human fossils recovered.

Unlike other bones of the skeleton, the ossicles are already fully formed and adult-sized at birth. This indicates that their size and shape is under very strong genetic control and, despite their small size, they hold a wealth of evolutionary information.

The study, led by Binghamton University anthropologist Rolf Quam, was carried out by an international team of researchers from institutions in the US, Italy and Spain. They analyzed several auditory ossicles representing the early hominin species Paranthropus robustus and Australopithecus africanus. The new study includes the oldest complete ossicular chain (i.e. all three ear bones) of a fossil hominin ever recovered. The bones date to around two million years ago and come from the well-known South African cave sites of Swartkrans and Sterkfontein, which have yielded abundant fossils of these early human ancestors.

The researchers report several significant findings from the study. The malleus is clearly human-like, and its size and shape can be easily distinguished from our closest living relatives, chimpanzees, gorillas and orangutans. Many aspects of the skull, teeth and skeleton in these early human ancestors remain quite primitive and ape-like, but the malleus is one of the very few features of these early hominins that is similar to our own species, Homo sapiens. Since both the early hominin species share this human-like malleus, the anatomical changes in this bone must have occurred very early in our evolutionary history. Says Quam, "Bipedalism (walking on two feet) and a reduction in the size of the canine teeth have long been held up as the "hallmark of humanity" since they seem to be present in the earliest human fossils recovered to date.

Our study suggests that the list may need to be updated to include changes in the malleus as well." More fossils from even earlier time periods are needed to corroborate this assertion, says Quam. In contrast to the malleus, the two other ear ossicles, the incus and stapes, appear more similar to chimpanzees, gorillas and orangutans. The ossicles, then, show an interesting mixture of ape-like and human-like features.

The anatomical differences from humans found in the ossicles, along with other differences in the outer, middle and inner ear, are consistent with different hearing capacities in these early hominin taxa compared to modern humans. Although the current study does not demonstrate this conclusively, the team plans on studying the functional aspects of the ear in these early hominins relying on 3D virtual reconstructions based on high resolution CT scans. The team has already applied this approach previously to the 500,000 year-old human fossils from the Sierra de Atapuerca in northern Spain. The fossils from this site represent the ancestors of the Neandertals, but the results suggested their hearing pattern already resembled Homo sapiens. Extending this type of analysis to Australopithecus and Paranthropus should provide new insight into when our modern human pattern of hearing may have evolved. The study has just been published in the Proceedings of the National Academy of Sciences.

PNAS: Early hominin auditory ossicles from South Africa

Hearing changes could be ancient in the human line
Nature News, 13 May 2013

<< It is hard to draw conclusions about hearing just from the shape of the middle-ear bones because the process involves so many different ear structures, as well as the brain itself. However, some studies have shown that the relative sizes of the middle-ear bones do affect what primates can hear. Genomic comparisons with gorillas have indicated that changes in the genes that code for these structures might also demarcate humans from apes.

Callum Ross, an evolutionary morphologist at the University of Chicago in Illinois, says the discovery of these ossicles was “a step in the right direction in the understanding of human hearing”. However he says he is “underwhelmed” by the findings, especially given that his own research has found that differences in the size and shape of the outer ear have a greater influence on the hearing sensitivities of primates than the dimensions of the middle-ear bones.

Ross also says that changes in the hearing apparatus are unlikely to have had as much impact on human cognition as the other morphological changes our ancestors experienced. “The truly important changes are in bipedalism, the feeding apparatus and, ultimately, brain size,” he says.

But Quam is confident that his team will soon demonstrate the importance of changes in the ossicles. “We are going to try and reconstruct the hearing capacities of these same specimens: then we will be able to say something about their sensory ecology,” he says.

Nature doi:10.1038/nature.2013.12976

Margarita

[neufer]

Very interesting!
Presumably you are you suggesting the possibility that the SN under discussion might have influenced this genetic mutation?

Possibly.

There was an interesting science show on about a year or so ago where it was discovered that humans have a defective hominid gene that prevents us from developing strong jaw muscles that connect to the top of the skull. Consequently, human baby skulls were not forced by those strong muscles to fuse together so soon in their development allowing for the baby's brain to grow within a pliable skull.

Perhaps a radiation induced a defective gene also prevented the ear bones to develop fully (or perhaps weaker jaw muscles led to different sized ear bones).

[MargaritaMc]

Very interesting!
Presumably you are you suggesting the possibility that the SN under discussion might have influenced this genetic mutation?

Possibly.

There was an interesting science show on about a year or so ago where it was discovered that humans have a defective hominid gene that prevents us from developing strong jaw muscles that connect to the top of the skull. Consequently, human baby skulls were not forced by those strong muscles to fuse together so soon in their development allowing for the baby's brain to grow within a pliable skull.

Perhaps a radiation induced a defective gene also prevented the ear bones to develop fully (or perhaps weaker jaw muscles led to different sized ear bones).

Yes. That sounds feasible.
I'd not heard of the research you mentioned, so looked it up for some details and found this fascinating information:

University of Pennsylvania, April 2004

Associate Professor of Surgery Hansell Stedman has discovered a clue that may help solve a long-running evolutionary puzzle—how the brain was able to expand, thus distinguishing humans from their primate predecessors.

He and his colleagues in the School of Medicine have found a genetic mutation that makes the jaw muscles of humans significantly smaller and weaker than those of primates. Since news of the discovery appeared in the March issue of Nature, media outlets worldwide have trumpeted the find as the “missing link” between apes and humans.

Stedman himself won’t go that far. “The reason the world seized on this has vastly more to do with its potential implications than it has to do precisely with what we’ve definitely proven,” he said.

What he says his team has proven is that all humans share a common genetic mutation—two base pairs of genes encoded for the muscle protein myosin, which all non-human primates have, are missing from their jaw muscles.

But wait a minute. What’s a surgeon doing working in the province of biologists and paleontologists?

“The intriguing part of this is that the original discovery would likely have been passed over for a significant bit of time if it had not been for the surgical background,” said Stedman. “Surgeons are used to thinking in terms of pathology and how one abnormality in one organ system might affect other organs around it.”

Stedman’s team made their discovery in the course of their work on muscular dystrophy. They have been working for several years on using gene transfer to restore normal muscle function. This led them to look at myosin, which governs muscle contraction. In the course of this work, they ran across the missing genes that led to the weakening of the human jaw.

As for why this mutation spread, Stedman dismisses the standard explanation that attributes it to dietary changes. Instead, he points out that primate jaws are used as weapons when they fight to establish dominance. He suspects that changes already taking place in the brain at the time may have helped the mutation along. At some time in ancient prehistory, he said, “It’s possible that an especially cunning male chimp might have been able to outwit a more powerful one, and if this mutation lifted an evolutionary constraint on brain growth, you can see where this all leads.”

Stedman said his team intends to explore the possibility that this mutation may have led to changes in the skull that made room for a larger brain. “We are simply not in a position to make any dogmatic assertions about how all of this happened, but we’re only half joking when we call this the room for thought mutation,” he said.

The World of Weird Things explains the physiological details
<< Human intelligence coming from a genetic defect just two base pairs long? Impossible! Balderdash! Evolutionist cultists losing their minds! It’s not like a single gene can produce a protein that determines how big a jaw muscle can grow and where it will ultimately attach, shaping the brain case. Oh wait, that’s exactly what MYH16 does.

By providing a blueprint to encode the protein myosin (or myosin heavy chain 16 if you want to get specific), it determines how big the muscle is going to be and with two missing base pairs, it just didn’t have enough protein to anchor the jaw muscles to a crest at the top of an ape skull as it should’ve. Instead, the muscle attached itself to the side of the head. In a normal ape, the fusion of the muscle with the crest forced the brain case to seal itself shut in just a few years. Without a huge jaw muscle sealing the skull, hominids would grow much larger heads. It was an evolutionary trade-off. We didn’t have killer jaws anymore, but we had a big new brain and with it, the beginnings of intelligence.>>

Margarita