On the basis of empirical evidence it is claimed that the view of the gradual oxygenation of oceans is wrong. The abstract of the article explains the findings.
Reconstructing the oxygenation history of Earth's oceans during the Ediacaran period (635 to 539 million years ago) has been challenging, and this has led to a polarizing debate about the environmental conditions that played host to the rise of animals. One focal point of this debate is the largest negative inorganic C-isotope excursion recognized in the geologic record, the Shuram excursion, and whether this relic tracks the global-scale oxygenation of Earth's deep oceans.
To help inform this debate, we conducted a detailed geochemical investigation of two siliciclastic-dominated successions from Oman deposited through the Shuram Formation. Iron speciation data from both successions indicate formation beneath an intermittently anoxic local water column. Authigenic thallium (Tl) isotopic compositions leached from both successions are indistinguishable from bulk upper continental crust (ε205TlA≈-2) and, by analogy with modern equivalents, likely representative of the ancient seawater ε205Tl value. A crustal seawater ε205Tl value requires limited manganese (Mn) oxide burial on the ancient seafloor, and by extension widely distributed anoxic sediment porewaters.
This inference is supported by muted redox-sensitive element enrichments (V, Mo, and U) and consistent with some combination of widespread (a) bottom water anoxia and (b) high sedimentary organic matter loading. Contrary to a classical hypothesis, our interpretations place the Shuram excursion, and any coeval animal evolutionary events, in a predominantly anoxic global ocean.
The absence of oxygenation before the Expolosion is also the TGD based prediction. The TGD based model predicts that the mysterious Cambrian Explosion in which advanced multicellulars suddenly emerged involved an increase of Earth radius by factor 2 in a geologically short time scale (see this and this).
This view conforms with TGD inspired cosmology in which a smooth cosmological expansion is replaced with a serious rapid step-wise expansions, which are essentially quantum phase transitions involving astrophysical quantum coherence scales.
The Earth would have been like Mars now (not much water at surface, even the radius would have been very near to Mars radius) and life would have evolved in underground oceans (being shielded from cosmic rays and meteors), in the womb of Mother Gaia. The evidence for the underground life on Mars is accumulating. The water in underground oceans would have oxygenated by photosynthesizing life and the underground water would have bursted to the surface and give rise to the oxygenated oceans covering most of the Earth's surface since then.
The basic objection is that photosynthesis was not possible. The core of the Earth however produces radiation in the same wavelength range as the Sun and in the TGD framework this could allow the development of photosynthesis (see this).
Whether the interpretation of the article that life evolved in anoxic global ocean is consistent with the TGD view that this oceans was essentially absent, is not of course clear.
What other objections can one invent against the TGD view? The first objection against the TGD proposal is that fossils of complex multicellular life forms have been found with age of 600 million years to be compared with the fossils dating back to 550 years ago when Cambrian explosion could have started. The story of their discovery told in the popular article "How 2 Teens Accidentally Solved Charles Darwin's Most Vexing Problem" (see this) is fascinating.
In 1956, a teenage girl by the name of Tina Negus found a strange looking fossil in Charnwood Forest in Leicestershire, England. The plant fossil should not have been there since the rock was 600 million years old and the Cambrian explosion started roughly 60 million years later. Tina Negus showed a pencil rubbing to his geography teacher but he didn't believe her.
A year later, in 1957, three teenage boys were playing near the same rock face when they, too, noticed the same fossil. One of these teens, fifteen-year-old Roger Mason, found the second fossil. Roger Mason contacted Trevor Ford, a local geologist, who wrote about the finding to the Journal of the Yorkshire Geological Society. The new plant was named Charnia Masoni. Charnia is a genus of frond-like life forms belonging to the Ediacaran biota. Charnia came from Charnwood Forest in Leicestershire, England where Tina Engus found it. Masoni is after Roger Mason.
Does the TGD based view survive these findings? Note first that the Charmia Masoni does not conform with the conclusion that the oceans that possibly existed at that time did not contain oxygen. Furthermore, Charnia Masoni does not change the basic facts: complex multicellular life forms emerged as if from nowhere. The time span from Charnia Masoni fossils about 600 billion years to the beginning of Cambrian Explosion about 538.8 million years ago is about 10 per cent.
Can one explain the finding in the TGD view of the Cambrian explosion?
- If the surface of Earth did not contain much water before the Cambrian Explosion, one can imagine that water leaked from the underground oceans locally at some places but not everywhere. Instead of oceans, there were oxygenated lakes, where multicellular life forms survived.
- Another possibility is that the expansion of Earth involves periodic oscillation typical of resonances so that bursts of oxygenated water containing the highly evolved life forms emerged to the surface. I have considered this kind of explanation for the periodic oscillations found to be associated with the Cambrian explosion.
See the article Expanding Earth Hypothesis and Pre-Cambrian Earth or the chapter Quantum gravitation and quantum biology in TGD Universe.
For a summary of earlier postings see Latest progress in TGD.
For the lists of articles (most of them published in journals founded by Huping Hu) and books about TGD see this.