Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




EARLY EARTH
'Cascade of events' caused sudden explosion of animal life
by Staff Writers
Oxford, UK (SPX) Sep 24, 2013


Theories for the Cambrian Explosion fall into three main categories - geological, geochemical and biological - and most have been claimed as standalone processes that were the main cause of the explosion.

The explosion of animal life on Earth around 520 million years ago was the result of a combination of interlinked factors rather than a single underlying cause, according to a new study. Dozens of individual theories have been put forward over the past few decades for this rapid diversification of animal species in the early Cambrian period of geological time.

But a paper by Professor Paul Smith of Oxford University and Professor David Harper of Durham University suggests a more holistic approach is required to discover the reasons behind what has become known as the Cambrian Explosion.

Theories for the Cambrian Explosion fall into three main categories - geological, geochemical and biological - and most have been claimed as standalone processes that were the main cause of the explosion.

Whatever the cause, this major evolutionary event led to a wide range of biological innovation, including the origin of modern ecosystems, a rapid increase in animal diversity, the origin of skeletons and the first appearance of specialist modes of life such as burrowing and swimming.

Among the weird and wonderful creatures to emerge in the early Cambrian was Anomalocaris, the free-swimming, metre-long top predator of the time with a mouth composed of 32 overlapping plates that could constrict to crush prey. It is distantly related to modern arthropods, including crabs and lobsters.

Vertebrate animals also made their first appearance in the Cambrian Explosion, the distant ancestors of modern fish, reptiles, birds and mammals.

Professor Smith, Professor Harper and a team of scientists have spent four years working on data from a site in northernmost Greenland, facing the Arctic Ocean.

The site, at Siriuspasset, is located at 83 N, just 500 miles from the North Pole in a remote part of north Greenland. Although logistically very difficult to reach, Siriuspasset attracted the team because of the high quality of its fossil material and the insights it provides.

Professor Smith and Professor Harper's findings are published in the latest edition of the journal Science.

Professor Smith, lead author of the report and Director of the Oxford University Museum of Natural History, said: 'This is a period of time that has attracted a lot of attention because it is when animals appear very abruptly in the fossil record, and in great diversity. Out of this event came nearly all of the major groups of animals that we recognise today.

'Because it is such a major biological event, it has attracted much opinion and speculation about its cause.'

Described by the researchers as a 'cascade of events', the interacting causes behind the explosion in animal life are likely to have begun with an early Cambrian sea level rise. This generated a large increase in the area of habitable seafloor, which in turn drove an increase in animal diversity. These early events then translate into the complex interaction of biological, geochemical and geological processes described in individual hypotheses.

Professor Harper, Professor of Palaeontology in the Department of Earth Sciences at Durham University, said: 'The Cambrian Explosion is one of the most important events in the history of life on our planet, establishing animals as the most visible part of the planet's marine ecosystems.

'It would be naive to think that any one cause ignited this phenomenal explosion of animal life. Rather, a chain reaction involving a number of biological and geological drivers kicked into gear, escalating the planet's diversity during a relatively short interval of deep time.

'The Cambrian Explosion set the scene for much of the subsequent marine life that built on cascading and nested feedback loops, linking the organisms and their environment, that first developed some 520 million years ago.'

Professor Smith said: 'Work at the Siriuspasset site in north Greenland has cemented our thinking that it wasn't a matter of saying one hypothesis is right and one is wrong. Rather than focusing on one single cause, we should be looking at the interaction of a number of different mechanisms.

'Most of the hypotheses have at least a kernel of truth, but each is insufficient to have been the single cause of the Cambrian explosion. What we need to do now is focus on the sequence of interconnected events and the way they related to each other - the initial geological triggers that led to the geochemical effects, followed by a range of biological processes.'

The paper 'Causes of the Cambrian Explosion' by M. Paul Smith and David A. T. Harper is published in Science, Vol. 341, 20 September 2013.

.


Related Links
University of Oxford
Explore The Early Earth at TerraDaily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EARLY EARTH
Researchers identify ancient ancestor of tulip tree line
Bloomington IN (SPX) Sep 16, 2013
The modern-day tulip tree, state tree of Indiana as well as Kentucky and Tennessee, can trace its lineage back to the time of the dinosaurs, according to newly published research by an Indiana University paleobotanist and a Russian botanist. The tulip tree, Liriodendron tulipfera, has been considered part of the magnolia family. But David Dilcher of Indiana University Bloomington and Mikha ... read more


EARLY EARTH
Mission to moon will boost research and awareness

Mighty Eagle Improves Autonomous Landing Software With Successful Flight

Watch Out for the Harvest Moon

Chang'e-3 lunar probe sent to launch site

EARLY EARTH
NASA Rover Inspects Pebbly Rocks at Martian Waypoint

Martian Life: Good or Bad?

Communications Tests Go the Distance for MAVEN

Curiosity Rover Detects No Methane On Mars

EARLY EARTH
"GRAVITY" is Almost Here

International Partnership Releases Space Exploration Benefits Paper

Iran to send second monkey into space

Voyager's departure from the heliosphere

EARLY EARTH
Chinese VP stresses peaceful use of space

China's space station to open for foreign peers

Last Days for Tiangong

China civilian technology satellites put into use

EARLY EARTH
New space crew joins ISS on Olympic torch mission

Station Crew Readies for Cygnus' Sunday Arrival

American, two Russians take shortcut to space

Tech glitch delays space station berthing to Saturday

EARLY EARTH
Arianespace and Astrium sign deal to begin production of 18 new Ariane 5 vehicles

Problems with Proton booster fixed

Decontamination continues at Baikonur after Proton abortive launc

Russia launches three communication satellites

EARLY EARTH
ESA selects SSTL to design Exoplanet satellite mission

Coldest Brown Dwarfs Blur Lines between Stars and Planets

NASA-funded Program Helps Amateur Astronomers Detect Alien Worlds

Observations strongly suggest distant super-Earth has water atmosphere

EARLY EARTH
Green photon beams more agile than optical tweezers

Space oddity: the mystery of 2013 QW1

Domain walls as new information storage medium

Invention jet prints nanostructures with self-assembling material




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement