Plate tectonics may have driven the evolution of life on Earth

The Cambrian explosion about 540 million years ago was when all the major living groups (phyla) of animal life appeared. Did a rise in oceanic trace elements initiate this event?
Credit: Wikia, CC BY-SA

When Charles Darwin published his theory of evolution by natural selection in 1859, the world hadn't even heard of plate tectonics. The notion that continents drifted on molten rock currents deep in the Earth's mantle was unimaginable.

So it would have come as a shock to Darwin to think the movement of the Earth's continental plates could have been a major driver of evolutionary change in all life.

In our research, published this month in Gondwana Research, we suggest that the regular collision of tectonic plates over the past 700 million years has been a prime driver of evolutionary change on Earth.

The essentials for life

We used laser technology housed in the Earth Science laboratories at the University of Tasmania to analyse more than 4,000 pyrite grains from seafloor mudstone samples collected from around the globe.

This enabled us to determine how concentrations of trace elements in the oceans have varied over the 700 million years. Trace elements included copper, zinc, phosphorus, cobalt and selenium, which are necessary for nearly all life – from marine phytoplankton through to humans – to function.

The most surprising finding was that there were certain periods in Earth's history when nutrient trace elements were highly enriched in the oceans, and other periods when levels of these critical trace elements were very low.

The nutrient-rich periods promoted rapid plankton growth in the short term, and this appears to correlate with periods of increased evolutionary change. An example of this is the rapid rise in trace elements preceding the Ediacaran (635 to 542 million years ago) and Cambrian (541 to 485 mya) periods, a time when multicellular animal life took off in a big way.

The Cambrian explosion, around 540 million years ago, is when most major groups of living animals appeared. This corresponds to a time when essential trace elements were peaking in the oceans, thus nutrient levels were very high.

The nutrient-poor periods caused depletion of plankton and promoted a slow-down in rates of diversification and ultimately could have played a role in three major mass extinction events. These occurred at the end of the Ordovician, Devonian and Triassic periods.

Although several possible explanations are given for these extinctions events, depletion in oceanic trace elements might be another plausible factor. Work is currently underway demonstrating that these events are tied to rapid declines in certain essential trace elements, particularly selenium.

Plate tectonics and nutrient cycles

Nutrients in the oceans ultimately come from weathering and erosion of rocks on thecontinents. Weathering breaks down the minerals in the rocks and releases thenutrient trace elements, which nourish life. Thus when weathering and erosion rates increase for extended periods, more nutrients are supplied to the oceans.

In the long term of geological history, erosion rates rise dramatically duringmountain building events caused by the gradual collision of tectonic plates.

Geologists have known since the 1960s that collisions of tectonic plates lead to the formation of huge mountain ranges. The Himalayas were formed when India, drifting northwards after splitting off from the supercontinent of Gondwana, slammed into Asia and pushed up the Tibetan Plateau. These collisions are called called orogenic events and their timing through Earth's history is now well established.

Continued erosion eventually depletes the surface of nutrients, causing a drop in the ocean's nutrients. This might have led to extinction events in the seas.

This is the first time nutrient trace element curves have been developed that demonstrate the relationship between tectonic collisions and the generation of cycles of nutrients.

While the link between these nutrient cycles as drivers of evolution and factors in mass extinction events remains to be proven, it really makes us think about evolution in a broad sense. Plate tectonics and evolution both operate on the same time scale of millions of years, and it seems logical that they could be causally related.

The relationship between increased nutrients in the oceans with bursts of evolutionary change are clearly correlated for the early part of the cycles, but less clear is the correlation with the evolution of advanced land animals.

Life out of the oceans

The origin of the first land animals, tetrapods about 370 million years ago, corresponds with a decrease in oceanic nutrients and a series of mass extinction events in the oceans. This could explain why certain sarcopterygian fishes with robust limbs left the seas when they did in order to leave the nutrient-poor ocean and make out on land.

But the first appearance of dinosaurs and mammals in the early Triassic, about 225 million years ago, has no correlation with trace element abundance.

Perhaps the cycles pertain mainly to biodiversity in the oceans. There is certainly a close correlation with the drop in nutrients and some global oceanic mass extinctions. These events are being tested and explored further in further research on selenium, to be released soon.

Τεράστιες δασικές πυρκαγιές στην Αθήνα Προάστια, Νότια Πελοπόννησο

Οι πυροσβέστες στην Ελλάδα μάχεται μαζικές πυρκαγιές στα περίχωρα της Αθήνας, και περισσότερες πυρκαγιές στη νότια Πελοπόννησο, που ανάγκασαν εκατοντάδες χωρικούς να εγκαταλείψουν.

Η φωτιά έξω από την πρωτεύουσα εξαπλώνονται γρήγορα, fanned από ισχυρούς ανέμους και καταβροχθίζουν τα μέρη των λόφων δημοφιλής με τους πεζοπόρους και τους τουρίστες. Σημεία της πόλης βρίσκεται σε παχύ καπνό.

Ο πρωθυπουργός Αλέξης Τσίπρας είπε ότι η Ελλάδα έχει ζητήσει βοήθεια από το στρατό της χώρας του και της δύναμης του αέρα, καθώς και το ευρωπαϊκό κέντρο αντιμετώπισης καταστάσεων έκτακτης ανάγκης. Δύο νερού-ρίψη αεροσκάφη είχαν απογειωθεί από τη δεύτερη μεγαλύτερη πόλη της χώρας, της Θεσσαλονίκης στο βορρά για να βοηθήσει με την φλόγα της Αθήνας, είπε.

Islamic State (ISIS) Child Jihadi Carries Out A Savage Beheading Of A Syrian Army Soldier

By BI: ‘Cub of the Caliphate,’  no older than about 10, is seen executing a Syrian Army soldier by decapitation as the terror group increasingly uses young boys to kill.

HEAVY  A new video (below) purportedly released by the Islamic State shows a young boy soldier beheading a Syrian army officer in Palmyra, Syria.

UK Daily Mail  Wearing camouflage and a black headdress, the boy’s face is uncovered – revealing a chilling dead-eyed stare that offers a glimpse of the evil he has witnessed carried out by ISIS’ killers.

The soldier is seen being forced to lay on his stomach as the young boy approaches him from behind, pulls his head back by the hair, and uses a small knife to slit the man’s throat and set about beheading him.

In a moment of true horror the child then lifts the victim’s severed head in a warped celebration of the brutal murder. He then places the head on the victim’s back.

Throughout the entire killing, a senior ISIS fighter is seen observing the shocking scene.  At the end of the video the older militant turns to the camera and makes a chilling threat to the West.

‘Our goal is not only Palmyra or Homs or Damascus, rather our goal is to conquer Bayt al- Maqdes [Jerusalem] and Rome, God willing,’ according to the UK-based Syrian Observatory for Human Rights, who say they were sent a copy of the video.

Fast Forward to 04:00 to skip the usual rantings

Bastille Day fireworks light up the Eiffel Tower in Paris

Βίντεο αποκαλύπτει τον ακριβή χρόνο της διαφυγής του Βαρωνου της κοκας Χοακίν "Ελ Chapo" Guzman--Revelan video del momento exacto de la fuga de Joaquín 'El Chapo' Guzmán

Η αστυνομία βίντεο δείχνει προσγείωση αεροπλάνου στην εθνική οδό--Police video shows plane landing on highway

ΟΙΚΟΠΕΔΑ ΙΟΝΙΟΥ και νοτίου ΚΡΗΤΗΣ: Παράταση στην... παράταση!

ΟΙΚΟΠΕΔΑ ΙΟΝΙΟΥ και νοτίου ΚΡΗΤΗΣ: Παράταση στην... παράταση!
Σήμερα 14 Ιουλίου 2015, στις 14.00, λήγει η προθεσμία υποβολής φακέλων προσφορών από τις εταιρίες που ενδιαφέρονται να αναλάβουν έρευνα και εκμετάλλευση υδρογονανθράκων στα οικόπεδα των περιοχών Ιονίου και νοτίως Κρήτης. Πρόκειται για την προκήρυξη που εξέδωσε η ελληννική κυβέρνηση προ ενός έτους (Υπ. Απ. D1/Α/12892/31.07.2014) και δημοσιεύθηκε στην Εφημερίδα της Κυβερνήσεως ως 2186/B/08.08.2014) ενώ δημοσιεύτηκε και στην Εφημερίδα των Ευρωπαϊκών Κοινοτήτων με αριθμό 2014/C400/03 στις 17 Νοεμβρίου 2014. Σ' αυτήν υπάρχουν οι χάρτες με τα υπό παραχώρηση 20 οικόπεδα.
Η αρχική προθεσμία έληξε στις 14 Μαίου 2015, χωρίς να παρουσιαστούν ενδιαφερόμενες εταιρίες! Δόθηκε παράταση 2 μηνών, μέχρι σήμερα δηλαδή. Ήδη, προ 4 ημερών, στις 10 Ιουλίου, εξαιτιας του κλεισίματος των Τραπεζών, η κυβέρνηση εξέδωσε ανακοίνωση με την οποία παρατείνει την υποβολή των προσφορών για 10 εργάσιμες ημέρες από την ημέρα που θα ανοίξουν οι Τράπεζες:
"Following restrictions applied on bank transactions in the context of the short-term bank holiday in Greece started in the 29th of June 2015, by means of the Legislative Act of the 28th of June 2015 (.......................) ...can be submitted to the Ministry (...), within a time period of ten (10) working days following the official end of the bank holiday."
Φαίνεται ωστόσο ότι τελικά δεν θα υπάρξουν προσφορές, εκτός ίσως από τα Ελληνικά Πετρέλαια (ΕΛΠΕ) που κατά πληροφορίες θα υποβάλλουν προσφορά για το οικόπεδο 1 (βορείως της Κέρκυρας) για το οποίο εξέφρασαν προσφάτως αμφισβητήσεις οι Αλβανοί.
Το γιατί δεν υπήρξε ενδιαφέρον από τις ξένες εταιρίες για τα οικόπεδα αυτά είναι ένα ζήτημα που έχει διάφορες αιτίες και ερμηνείες που ίσως αναλυθούν και λεπτομερέστερα σε άλλο ευρύτερο κείμενο. (Δρ Ι. Παρίσης / 14-7-15)

Οι μυστικες Πισίνες από τις Κατακόμβες του Παρισιού--The Secret Swimming Pools of the Paris Catacombs

The Secret Swimming Pools of the Paris Catacombs

It felt like the pavements of Paris could have melted this month. The city’s swimming pools were filled with splashing bodies and escape from the heat seemed futile. But there is one place, beneath the baking pavements, where only few will venture and plunge into the cool waters of the underworld. So let’s follow them to the deep end, the Parisian explorers known locally as the “cataphyles”, to find the secret swimming pools of the catacombs…

A friend of a friend of a friend, (that’s how these sort of clandestine connections only ever come about), an Australian ex-pat in Paris with a moustache that Dali would be proud of, Alexander J.E. Bradley can usually be found on the rooftops of Paris, 30 meters above ground or 30m below the streets in the catacombs, happily snapping away with his troupe of fellow creatives and urban explorers.

As an all-round purveyor of the occult in Paris, he’s teamed up with some pretty interesting characters of the underworld to create his films, stage his performance art and document it all with his camera over the past few years. One such character he’s encountered is a Parisian cataphyle who goes by the codename “Plongeur” (Diver), simply because he’s had the incredibly good fortune of going scuba diving beneath the city of Paris.

The often flooded and forgotten century-old tunnels have been his aquatic playground for more than 30 years and the brave diver has explored hundreds of meters of unknown galleries. The only reason the Department of Quarries inspection now knows of the existence of many of these tunnels is because he mapped them.

Together with the anonymous “Plongeur”, Bradley and his production team Mais Oui! made a fascinating short film about their experience following the local diver to plunge into the labyrinth of lost passages and discover what lies beneath the unknown waters of the catacombs. If you have any interest at all in Paris and its secrets of the underworld (which I have a sneaky feeling you do), “The City of the Sea” is something I think you really need to see…

Make sure to turn on the English subtitles if you need them in the bottom right hand corner. 

For a chilling moment there, it felt like they had discovered a lost “Atlantis” city beneath the streets of Paris.

Since his first descent into the watery deep of the catacombs with Plongeur, Bradley and his circle have began making their own trips to cool off in the secret swimming pools of the catacombs, and you can bet that he’ll be down there during the Parisian heat waves this summer for a clandestine pool party.

This is his privilege, having been passed on the knowledge and responsibility, from one cataphyle to another. So before you start enquiring if you can join on his next subterranean swimming session, bear in mind this is not in any way for a leisurely activity for beginners. Crouching over in one meter high pitch-black tunnels and trudging through murky waters up to your waist is not something you’re ever prepared for– even if there is the promise of crystal clear blue waters at the end of the tunnel. Cataphyles do not easily welcome first-timers, or what they call “tourists”. And of course, it’s all very illegal. So, be careful what you ask for.