posted
The ozone layer was destroyed 35,000 years ago in a disaster which lasted 2,000 years. At that time, people were nomadic hunters, and it helped rather than slowed human evolution.
The cause was the closest supernova explosion in known history - the disruption of a star 150 light-years away - which ripped away the ozone layer and bombarded Earth with violent shock waves of cosmic rays. Evidence comes from the discovery of the element beryllium-10 in the Greenland and Antarctic ice caps. Prof Grant Kocharov, vice-chairman of the Cosmic Ray Council of the Soviet Academy of Sciences, said:
“The explosion must have unleashed violent showers of cosmic rays which smashed into nitrogen and oxygen molecules in the atmosphere, producing beryllium-10.”
Mr Ian Ridpath, editor of the British journal Popular Astronomy, said:
“For several months, the exploding star would have been brighter than the full Moon. It would have been painful to the eye to look at. It would have cast shadows and turned night into day.”
The physical effects on our ancestors would have been cataclysmic.
“In successive shock-waves that would have lasted for more than 100 human generations, the Earth would have been bombarded both by cosmic rays and by ultraviolet radiation from the Sun as the ozone layer was ripped away,” he said. “Those who were prone to cancer would have died prematurely, but descendants of the survivors would have developed immune defences.”
Novae, especially supernovae, would generate high energy cosmic rays that would impact on acceleration of creature DNA gene mutation during this period, thus create lots of new species. The best supernova rate estimate we can offer indicates that one or more supernova explosions are likely to have occurred within 10 pc or so of the Earth during the Phanerozoic era, i.e., during the last 570 million years since the sudden biological diversification at the start of the Cambrian. Reference https://www.physicsforums.com/threads/high-energy-cosmic-rays-and-the-origin-of-life.635338/[/I]
The whole matter of subtle mutations, reinforcing environmental pressures, aiding or provoking jumps in culture, coinciding with extraordinary periods of extra-solar or cosmic radiation bore deeper examination.
A severe blast of extra-solar or solar radiation would have caused extinctions amongst marginal species throughout the range of life. Hairless humans would have suffered and those who lived outside the tropics, the ones who were ‘white’, would have suffered most from strange solar peaks, if not catastrophically. The demise of the Neanderthals could have been accelerated quite simply because they were pale-skinned.
Dark-skinned races of Africa, tropical Asia and Australasia would have been least at risk from unrestrained ultraviolet radiation, but those bursts of cosmic radiation must have caused random mutation in all lifeforms.
Robert Uhlig went on to write:
Prof. Dar said this theory [meteor crash] did not explain the great leap in biodiversity following the mass extinctions. He argued that the vast amount of radiation produced by a neutron star collision explained why 166 the number of animal and plant species increased so quickly after mass extinctions.
At about the 80,000 years ago event, the out-of-Africa migration of modern people began, as shown by the genetic evidence. Critics of the theory have asked why it was that modern mankind began moving so purposefully about the planet at that time. The reason that I had to accept was that there was population growth following good times in eastern Africa and climatic change; a dry period in the northeast around the Horn, precipitated a nomadic thrust.
I have referred to Stephen Oppenheiner and his book Out of Eden (2003) and Christopher Springer & Robin McKie in African Exodus (1996) in previous discussion on this particular problem. But, the promotion of this behaviour may have been precipitated or facilitated by subtle mutation in their brains caused by cosmic radiation.
posted
I'm not 100% sure of this. It all depends on exactly when the OCA mutation first appeared. I would not be surprised if this was just one of many such solar events occurring in earth's history.
However, the OP is taken from a Physics forum consisting mostly of white posters. Many aspects of this theory are inferred veiled opinions that solar mutations caused the OCA mutation, and this is what led to Africa's explosion of diversity, as well as the evolution of white people.
-------------------- Selenium gives real life and true reality Posts: 4693 | From: Saturn | Registered: Apr 2012
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quote:Originally posted by kdolo: . "The demise of the Neanderthals could have been accelerated quite simply because they were pale-skinned."
Neandathals werent pale skin
See Llauesa-Fox, et. al. 2007 “A Melanocortin 1 Receptor Allele Suggests Varying Pigmentation Among Neanderthals,” www.sciencexpress.org / 25 October 2007 / Page 1 / 10.1126/science.1147417
Abstract
The melanocortin 1 receptor (MC1R) regulates pigmentation in humans and other vertebrates. Variants of MC1R with reduced function are associated with pale skin color and red hair in humans primarily of European origin. We amplified and sequenced a fragment of the MC1R gene (mc1r) from two Neanderthal remains. Both specimens have a mutation not found in ~3700 modern humans. Functional analyses show that this variant reduces MC1R activity to a level that alters hair and/or skin pigmentation in humans. The impaired activity of this variant suggests that Neanderthals varied in pigmentation levels, potentially to the scale observed in modern humans. Our data suggest that inactive MC1 variants evolved independently in both modern humans and Neanderthals.
Posts: 833 | From: Austin, TX | Registered: Jan 2007
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posted
Interesting that the KhoiSan people seemed to have endured this "cataclysm" with their apricot skin tone presumably on the open spaces of southern Africa. Rainforest pygmy people probably weren't affected much, nor northern populations wearing skin clothing most of the year.
Mainly people who spent all year only partly shadowed in tropical areas with little clothing would have probably had the strongest selection influence. Possibly this caused the change to conical thickly-thatched housing?
quote:Originally posted by kdolo: . "The demise of the Neanderthals could have been accelerated quite simply because they were pale-skinned."
Neandathals werent pale skin
See Llauesa-Fox, et. al. 2007 “A Melanocortin 1 Receptor Allele Suggests Varying Pigmentation Among Neanderthals,” www.sciencexpress.org / 25 October 2007 / Page 1 / 10.1126/science.1147417
Abstract
The melanocortin 1 receptor (MC1R) regulates pigmentation in humans and other vertebrates. Variants of MC1R with reduced function are associated with pale skin color and red hair in humans primarily of European origin. We amplified and sequenced a fragment of the MC1R gene (mc1r) from two Neanderthal remains. Both specimens have a mutation not found in ~3700 modern humans. Functional analyses show that this variant reduces MC1R activity to a level that alters hair and/or skin pigmentation in humans. The impaired activity of this variant suggests that Neanderthals varied in pigmentation levels, potentially to the scale observed in modern humans. Our data suggest that inactive MC1 variants evolved independently in both modern humans and Neanderthals.
Yes, as things stand today, this seems most plausible with Neanderthals having diverse pigmentation.
I may pick on Nina for her efforts to refute, yet maintain racial theory, but many of the small details in her work are sensible.
Nina Jablonski theorizes that modern white humans gained enhanced immunity systems by mating with Neanderthals implying that there may not have been any as light as "Caucasians" whose immunity was compromised by OCA.
She also agrees that RACE is no more than an artificial social construct.
Mutations are caused when energetic photons or particles cause damage to the DNA molecule. Only ionizing radiation is capable of causing such damage, therefore most sunlight is not destructive. (However, UV, which is mostly shielded by the atmosphere, can be dangerous, particularly if doses are increased). This makes evolutionary sense too, because life could not have existed in presence of background radiation with too high a mutation rate. However, as we have discussed earlier, astrophysical objects affecting the Earth can cause a radiation burst, which in turn can trigger the mutation process on a large scale.
Although there is ample evidence that our earliest ancestors migrated from Africa, most probably in search of new resources of food as early as 70,000-80,000 years ago, there exist only tiny glimpses of what we were capable of achieving at this time. For instance, around 80,000 years ago the peoples of the republic of Congo were making barbed bone hooks for fishing, while a community that inhabited a large cave at a place called Blombos on the southern coast of South Africa would seem to have fashioned the earliest known examples of expressive art. These take the form of incised pieces of red ochre, showing recurring cross-hatch designs, as well as perforated snail shell beads, once strung on a cord and worn either as a necklace or bracelet. All of these invaluable objects are thought to be around 75,000 years old. Then there is the recently discovered archaeological evidence from a remote mountain cave in Botswana sacred to the indigenous San bushmen. This shows that ritual activity has been occurring here in a similar manner for anything up to 70,000 years, around the time when the first migrations out of Africa are thought to have occurred. Strangely, this was also when the ice core samples tell us that there was a dramatic increase in cosmic radiation hitting the earth, the first of three major bursts in the past 100,000 years.
When it comes to visible and near-visible photons, the most damaging radiation to human DNA is UV, specifically UVB and UVC. UVC is very effectively shielded by the atmosphere. UVB is easily absorbed by the DNA and causes maximum damage. In order to get an increase in UVB the incident radiation should have enough energy to ionize the upper atmosphere and deplete the ozone layer. Once the ozone layer is depleted, solar UVB can easily pass through it and directly interact with the DNA. Sources of such radiation can be galactic gamma-ray bursts (GRBs), nearby supernovae, or energetic solar proton events.
Galactic GRBs, although not frequent, have a non-trivial probability of impacting the Earth on timescales of the order of a few hundred million years. The energy released by GRBs is up to 10x45J within a few seconds to a minute. Short GRBs have less total energy, but a harder spectrum as compared to the long, and are more frequent and therefore, total energy likely to be deposited in the atmosphere from such an event is similar. It has also been shown that the dominant parameter affecting the atmospheric damage is the total fluence, followed by the spectrum. The time development of the ionizing event has very little effect.
In this illustration, a jet is produced by an unusually bright gamma-ray burst. Credit: NASA/Swift/Cruz deWilde
These findings suggest that a nearby gamma-ray burst may have caused one of the five greatest mass extinctions on Earth, such as the Ordovician extinction that occurred 440 million years ago. The Ordovician extinction was the earliest of the so-called Big Five extinction events, and is thought by many to be the second largest.
According to their findings, when large amounts of radiation collide with the atmosphere, the life on our planet can have serious problems. When these particles crash with the ozone layer, they form large amounts o nitric oxide, for that an oxygen atom is used which breaks the ozone molecules. This is catastrophic for lifeforms as it destroys the shield that protects us from the most powerful solar radiation, causing the destruction of the DNA in cells of living organisms. This means mass extinction on Earth. Jimenez believes that some species might survive this catastrophe living deep beneath the surface.
Jimenez estimates that Earth has been “hit” by five of these gamma-ray bursts.
Energetic solar flares occur much closer to the Earth at a higher rate but the energy in a given event is several orders of magnitude smaller. It has been shown in some cases that particles are accelerated to an energy of ~20 GeV in extreme cases. The rate is not well constrained for large events. In such cases, in addition to the damage caused to the atmosphere, muons will be produced from extreme hard spectra events, causing damage to the surface and near-surface organisms. Since the energy of such particles is high enough to penetrate the geomagnetic field, the extent of damage will be global, unlike low energy particles, which are mostly concentrated near polar regions.
On timescales of a few hundred million-years, nearby supernovae can significantly increase the flux of high-energy cosmic rays. This can significantly increase the effects of solar UVB and muon radiation dose on the surface.
DNA Damage caused by radiation is directly proportional to the amount of energy deposited in the irradiated substance. Absorbed radiation dose, D is defined as the amount of energy absorbed per unit mass of the substance, D = dE/dM. The standard unit of D is Gray, defined as 1J/kg. This quantity is a broad indicator of the level of damage and corresponding radiobiological and clinical effects irrespective of the type and nature of the radiation source.
Another quantity to characterize biological damage is LET (Linear Energy Transfer), which is the average amount of energy deposited per unit length of the substance or LET = dE/dx. LET can be computed using the Bethe-Bloch equation for any given radiation source and substance. This equation gives at a microscopic level the amount of ionization produced in a substance and is a finer indicator of radiation damage as compared to the radiation dose.
It must also be mentioned that cells have natural repair mechanisms and the resulting biological damage cannot be completely characterized by simple physics equations. Since organisms are very complex and heterogeneous, radiation damage at certain sites have greater impact compared to others. Also, different radiation types produce different types of ionization trails, which are energy dependent. For example, a 10 keV photon and a 10 keV alpha particle will have very different ionization tracks and will produce different biological effects. In other words, different radiation types produce different effects, even if the absorbed dose is same. Some radiation types are more effective than others and a different measure called the Relative Biological Effectiveness (RBE) is used to quantify such differences.
Posts: 4693 | From: Saturn | Registered: Apr 2012
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quote:Originally posted by Clyde Winters: The idea solar energy influences the origin of human populations relate to my ideas about the role of melanin in evolution.
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Dr. Winters, this is a great integration of the spiritual with the scientific nature of black people. Where "black" signifies those with enhanced Eumelanin rich biologies.
Your paper was truly ahead of it's time and refreshes the reader with knowledge which has been known, but lost.
An updated version of this paper would be a clear best seller and guide to today's youth.
Today we know that Eumelanin is the human interface to interact with our cosmic reality, and the main Eumelanin components of Selenium and copper enable us to capture, integrate and store all of the energies and information contained in the universe, including the elusive and dominate, Dark matter.
This eumelanin laced throughout our physical bodies act to tether us to the universe as well as to the planet by way of our second external brain; The skin network of Eumelanin melanocytes. The second brain network is also what connects us to the universal intelligence of the cosmos. I believe that we not only receive information by this path, but the path is bi-directional, and the universe is able to receive real-time information from us as well.
Posts: 4693 | From: Saturn | Registered: Apr 2012
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quote:Originally posted by DD'eDeN: Interesting that the KhoiSan people seemed to have endured this "cataclysm" with their apricot skin tone presumably on the open spaces of southern Africa. Rainforest pygmy people probably weren't affected much, nor northern populations wearing skin clothing most of the year.
Mainly people who spent all year only partly shadowed in tropical areas with little clothing would have probably had the strongest selection influence. Possibly this caused the change to conical thickly-thatched housing?
Not all Khoi & San people have light skin:
Sometimes, it seems that some folks are "pushing" an agenda that all Khoisan peoples look like this little baby (Which isn't true at all) : Posts: 117 | From: Earth | Registered: Feb 2014
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posted
Actually the last photo's baby seems lighter than typical KhoiSan, perhaps some Boer mixture?
The second and third photos show a dark green background, atypical for the Kalahari, dark skin would be better camouflage. There's been lots of admixture since the Bantu diaspora etc., exact same thing with the Pygmies in some areas, darker and taller than the ones more isolated.
Unfortunately people tend to focus on just pictures of the face/body, not the architecture/culture/language elements.
If a Black person is any person with dark skin one could argue that is not an example of race But if you say that there is more to being identified as a Black person than just dark skin then you believe in race
Posts: 42922 | From: , | Registered: Jan 2010
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quote:Originally posted by DD'eDeN: Actually the last photo's baby seems lighter than typical KhoiSan, perhaps some Boer mixture?
The second and third photos show a dark green background, atypical for the Kalahari, dark skin would be better camouflage. There's been lots of admixture since the Bantu diaspora etc., exact same thing with the Pygmies in some areas, darker and taller than the ones more isolated.
Unfortunately people tend to focus on just pictures of the face/body, not the architecture/culture/language elements.
Babies, especially those possessing the OCA genetics, are often born light and darken as they age. This baby may become 2-3 times as dark in it's teen years.
So, with the exception of OCA1, you can't really gauge a person's adult skin tone from a baby photo.
Mayo Albinism Clinic
SKIN
For some people with albinism, skin pigmentation never changes. For others, melanin production may begin or increase during childhood and the teen years, resulting in slight changes in pigmentation.
So, it's very probable that the baby's skin tone may later develop to appear just like her mother or father's.
Posts: 4693 | From: Saturn | Registered: Apr 2012
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posted
I'd expect some tanning due to continuous daily solar exposure in the Kalahari, same thing in very melanized babies (though not visible to the naked eye).
quote:Originally posted by DD'eDeN: I'd expect some tanning due to continuous daily solar exposure in the Kalahari, same thing in very melanized babies (though not visible to the naked eye).
Albinos (real ones with pink eyes) don't tan.
Skin tone will darken because babies have not yet developed it's maximum number of skin melanocytes. Same with hair density, for example. Melanocyte density will increase over time, and as it increases, so does a darker skin tone. Environmental UV exposure also contributes to the number of melanocytes and density.
Posts: 4693 | From: Saturn | Registered: Apr 2012
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