The Ocean as a natural heritage

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THE ORIGIN OF LIFE

Microbial life originated in the ocean an estimated 3.6 billion years ago, and eukaryotic life some 2.1 to 3.0 billion years ago. A wide diversity of multicellular life appeared some 1.26-0.95 billion years ago. Land became colonized by green plants 0.60 billion years ago and man has joined life on earth a mere 200,000 years ago. The long evolution on Planet Ocean has generated a wealth of biodiversity at the gene, species and ecosystem level. Some aspects have received a disproportionate level of attention with concentration on a top down approach where organisms close to man such as whales, fish and shellfish have been prioritized. In contrast others have been neglected, such as the microbes and viruses. Genomics helps with this.

GENOMICS AND THE TREE OF LIFE

The Tree of Life
The Tree of Life describes the relationships of all living organisms, including bacterial (Eubacteria and Archaea) and eukaryotic organisms on earth in an evolutionary context. Whereas this was initially the task of biologists (taxonomists and systematicists), it has become a joint venture with evolutionary biologists and bioinformaticians. Highthroughput DNA sequencing has revolutionised the field. Comparing gene sequences has revealed completely new domains (and phyla), but has also made clear that morphologically similar but genetically different species abound and that the census to date represents serious underestimates.

A total of 212,000 species have been identified in the ocean (Jaume & Duarte 2006), but the tally on species diversity is expected to reach millions, possibly even more than on land. However, we know very little about most species identified, let alone those yet to be discovered. Building the ultimate Tree of Life is a huge challenge, and several conditions have to be met.

LOSS OF BIODIVERSITY

Why do we prepare seemingly endless lists of species of marine organisms? It is foremost an attempt to understand the functioning of the biosphere and hence to help manage the services and goods delivered. Organisms occupy habitats and form an integral part of ecosystems, whose function and dynamics are determined by the variety, abundance and activities of these organisms. The diversity shift is monitored through taxonomic experts and compiled in a global database Census of Marine Life – CoML. There is growing evidence for the loss of population diversity, where smaller or more delicate (e.g., deep-sea and polar) populations are the first victims (Reynolds et al. 2005).




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References

  1. Volckaert F.A.M., Barbier M., Canário A.V.M., Clark M.S., Glöckner F.O., Olsen J.L., Wesnigk J., Boyen C. (2008) Marine Genomics Europe. The European flagship of marine sciences for a sustainable future. 38 pp. Marine Genomics Europe, EC-FP6 GOCE-CT-2004-505403

Category:The European Flagship in Marine Sciences for a Sustainable Future