The Palaeontological Association.
Thursday 18th December 2005
When life first became complicated!
Leading a complicated life is one thing, but making all Life on Earth complicated is another. The first the steps in this direction were taken hundreds of millions of years ago! The 49th Meeting of the Palaeontological Association at the University of Oxford will be exploring this and many other questions raised about the evolutionary history of life on Earth, and the
first day of the meeting will concentrate on these first steps towards a complicated life.
Life appeared on Earth at least 3.5 billion years ago, but the first 3 billion years were dominated by microbial life. Life was really quite simple. Complex life has its origin in the most recent billion years of Earth history. Modern molecular clocks imply that animals originated 600-900 million years ago, a time period when Earth was close to being an Ice-house planet.
The explosion of complex life in the Cambrian Period (540-500 million years ago) has received much attention by authors such as Stephen J. Gould (Wonderful Life, 1989). The beautifully preserved fossils of the Burgess Shale (British Columbia, Canada) provided one of our first glimpses at these early animals, some 505 million years old. However, a group of even more ancient fossils pushed the timing of the origin of complex life back to a time when the planet was recovering from extensive glaciation, some 600 million years ago.
The assemblage comprises marine organisms of Ediacaran (latest Precambrian, 620 to 543 Ma) age, placing them among the oldest multi-cellular fossils known. These animals had their heyday some 20 million years or more, before the Cambrian Explosion when recognisably modern multicellular life began to diversify rapidly. These fossils have become collectively known as the Ediacaran fauna, after the important fossil locality in the Ediacara Hills in southern Australia. Ediacaran fossils are also known from localities in England, Ireland, Canada, Namibia, Russia, Ukraine and Scandinavia. Some of the fossils have been known since the 1860's, when they were discovered
by quarry workers in Shropshire, but they were originally thought to be impressions of ancient gas bubbles. They were subsequently recognised as early animals by one of the first professional geologists, John William Salter, in 1856, but were related to other elements of the Ediacara fauna only this year.
While early workers had an uphill battle to convince their colleagues that there could be fossils in such old rocks, their interpretation as soft bodied animals became acceptable in the 1960s and 1970s. Workers at that
time mostly considered them to be examples of modern groups such as sea pens, jellyfish, worms and arthropods, but more recently, they have been considered to be an evolutionary experiment in life, the fossils representing a type of life that was neither plant nor animal. The debate about
these rare and beautiful fossils is still raging today. This year’s Palaeontological Association meeting in Oxford will take the next step in unravelling this complex story of life on Earth.
For images and information on The Palaeontological Associations 49th meeting in Oxford, contact:
Dr Phil Manning, Publicity Officer (The Palaeontological Association), based at the University of Manchester.
Mobile: 07887 585487
Office: 0161-275-2660
email:[email protected]
Or
Conference organiser, Dr Derek Siveter, University Research Lecturer and Reader in Earth Sciences, University of Oxford, Tel: 01865 272953, email:
[email protected]
The Palaeontological Association.
Thursday 16th December 2004
Did the Earth Move for you?
Why don’t we have kangaroos bounding down Oxford Street today or herds of Wildebeest sweeping majestically past Torquay hotel windows? In the words of Jonathan Swift, ‘
The past is a different place, they do things differently there’.
Leading palaeontologists from the UK are flocking to the University town of Lille (France) this weekend to ponder such enormous questions. This is the 48th meeting of the Palaeontological Association (17-20 Dec.),
with some 250 scientists meeting to discuss the biggest story on the planet. Life.
The past was a very different place, if not a different world. Life on Earth has often left tantalising fossil clues for palaeontologists to reconstruct
this ancient world of extinct plants and animals. The meeting in Lille this weekend is highlighting the importance of fossils when reconstructing ancient
maps of the world (palaeogeographies) and the impact these geographies had on the course and diversity of life in the past.
Leading palaeontologist and best-selling author, Professor Richard Fortey of the Natural History Museum (London) is a key speaker at the meeting. His work on life in the ancient oceans, 500 million years ago, shows the
importance of fossil in defining ancient shorelines and long extinct oceans. The fossil evidence for these past worlds was recognised long before a mechanism was understood for the global ballet that moves continents, creates seas and destroys oceans. This relatively young science of matching ancients worlds to the plants and animals that inhabited them will provide answers
to many questions pondered by palaeontologists over the last two centuries.
As we sample fossil life from the planet’s past, spare a thought for the poor palaeontologist. The ‘story’ of life we weave is a reflection of the fossils we find and where they are found. If we dig in the ‘wrong’ place, our interpretation might lead something to be desired. It’s a bit like an alien spaceship sampling our world today…and they happen to choose Australia as their sample of life
on Earth. This would leave a rather inaccurate representation of life on Earth today, with sheep, pouched marsupials, egg-laying mammals and the occasional human making up their sample.
The relative position of land, seas and oceans has a major impact on climate, environment and the evolution of plants and animals that live on Earth today. By understanding the effects of these processes on life in the past, we might hope to understand how the Earth moves for life in the future.
For images and information on The Palaeontological Associations 48th
meeting in Lille, contact:
Dr Phil Manning, Publicity Officer
(The Palaeontological Association, London), based at the University of Manchester.
Mobile: 07887 585487
Office: 0161-275-2660
email:[email protected]
Or
Conference organiser,Dr
Thomas Servais, Universite de Sciences et Technologies de Lille, France