23 August 2010 Last updated at 21:26 GMT
‘Survival of fittest’ is disputed
By Howard Falcon-LangScience reporter, BBC News
Space is the final frontier for evolution, a study suggests.
It proposes that Charles Darwin may have been wrong when he argued that competition was the major driving force of evolution.
He imagined a world in which organisms battled for supremacy and only the fittest survived.
But new research identifies the availability of "living space", rather than competition, as being of key importance for evolution.
Findings question the old adage of "nature red in tooth and claw".
The study conducted by PhD student Sarda Sahney and colleagues at the University of Bristol is published in Biology Letters.
The research team used fossils to study evolutionary patterns over 400 million years of history.
Focusing on land animals - amphibians, reptiles, mammals and birds - the scientists showed that the amount of biodiversity closely matched the availability of "living space" through time.
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Read more here/Leia mais aqui: BBC
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Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land
Sarda Sahney1,*, Michael J. Benton1 and Paul A. Ferry2
+Author Affiliations
1Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol BS8 1RJ, UK
2Eikonworks, 805 3rd Street, Canmore, Alberta, Canada T1W 2J2
*Author for correspondence (s.sahney@bristol.ac.uk).
Abstract
Tetrapod biodiversity today is great; over the past 400 Myr since vertebrates moved onto land, global tetrapod diversity has risen exponentially, punctuated by losses during major extinctions. There are links between the total global diversity of tetrapods and the diversity of their ecological roles, yet no one fully understands the interplay of these two aspects of biodiversity and a numerical analysis of this relationship has not so far been undertaken. Here we show that the global taxonomic and ecological diversity of tetrapods are closely linked. Throughout geological time, patterns of global diversity of tetrapod families show 97 per cent correlation with ecological modes. Global taxonomic and ecological diversity of this group correlates closely with the dominant classes of tetrapods (amphibians in the Palaeozoic, reptiles in the Mesozoic, birds and mammals in the Cenozoic). These groups have driven ecological diversity by expansion and contraction of occupied ecospace, rather than by direct competition within existing ecospace and each group has used ecospace at a greater rate than their predecessors.
biodiversity diversity ecology expansion tetrapods vertebrates
Footnotes
Received December 9, 2009.
Accepted January 3, 2010.
© 2010 The Royal Society
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