How Many Species Are There on Earth and in the Ocean?

The diversity of life is one of the most striking aspects of our planet; hence knowing how many species inhabit Earth is among the most fundamental questions in science. Yet the answer to this question remains enigmatic, as efforts to sample the world’s biodiversity to date have been limited and thus have precluded direct quantification of global species richness, and because indirect estimates rely on assumptions that have proven highly controversial. Here we show that the higher taxonomic classification of species (i.e., the assignment of species to phylum, class, order, family, and genus) follows a consistent and predictable pattern from which the total number of species in a taxonomic group

can be estimated. This approach was validated against well-known taxa, and when applied to all domains of life, it predicts ~8.7 million (±1.3 million SE) eukaryotic species globally, of which ~2.2 million (±0.18 million SE) are marine. In spite of 250 years of taxonomic classification and over 1.2 million species already catalogued in a central database, our results suggest that some 86% of existing species on Earth and 91% of species in the ocean still await description. Renewed interest in further exploration and taxonomy is required if this significant gap in our knowledge of life on Earth is to be closed. Knowing the number of species on Earth is one of the most basic yet elusive questions in science. Unfortunately, obtaining an accurate number is constrained by the fact that most species remain to be described and because indirect attempts to answer this question have been highly controversial. Here, we document that the taxonomic classification of species into higher taxonomic groups (from genera to phyla) follows a consistent pattern from which the total number of species in any taxonomic group can be predicted. Assessment of this pattern for all kingdoms of life on Earth predicts ~8.7 million (±1.3 million SE) species globally, of which ~2.2 million (±0.18 million SE) are marine. Our results suggest that some

86% of the species on Earth, and 91% in the ocean, still await description. Closing this knowledge gap will require a renewed interest in exploration and taxonomy, and a continuing effort to catalogue existing biodiversity data in publicly available databases. Citation: Mora C, Tittensor DP, Adl S, Simpson AGB, Worm B (2011) How Many Species Are There on Earth and in the Ocean? PLoS Biol 9(8): e1001127. doi:10.1371/journal.pbio.1001127 Academic Editor: Georgina M. Mace, Imperial College London, United Kingdom.Received: November 12, 2010; Accepted: July 13, 2011; Published: August 23, 2011 – Copyright: © 2011 Mora et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Funding: Funding was provided by the Sloan Foundation through the Census of Marine Life Program, Future of Marine Animal Populations project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.  – Professor  Georgina 

Mace. Current collaborative research projects; Ecosystem Services for Poverty Alleviation (ESPA). I am Associate Director (Knowledge) for this seven year programme funded by DfID, NERC and ESRC.Valuing Nature Network. I am a Co-Investigator in this two year programme funded by NERC.The UK National Ecosystem Assessment. (NEA) I am coordinating lead author for the Conceptual Framework.Research Interests:Biodiversity assessment; Biodiversity is a concept that is hard to summarise but its increasing policy presence means that it is important to consider how best to measure it. In terms of many national and international policy contexts, this means that it needs to reflect more than simple measures of species and population diversity. I am interested in the ecological and evolutionary aspects of biodiversity science that should be incorporated into measures of biodiversity that relate to ecosystem services.Climate change impacts on species and ecosystems;Existing methods for assessing climate change impacts tend to include rather little biology and be based on

spatial distributions and environmental associations. Yet species, population and community responses to climate change will be mediated through their ecology and evolutionary history. Currently I am working with colleagues to identify and prioritise the aspects of species biology that will most affect species and population vulnerability. Part of this work is directed towards determining the extent to which biotas and regions at high risk in the future will differ from those now at risk. Species extinction risk; My interests are in the identification and characterisation of species at high extinction risk. I worked with IUCN to develop criteria and rules for species to be included in the IUCN Red List of Threatened Species. Current projects in this area are aimed at determining how well the pattern of current population decline serves as a reliable signal for the causes of the decline, and therefore a good predictor of future trends; and on criteria for listing species threatened by climate change in the IUCN Red List. Sources: Imperial College London & PLoS Biology : Publishing science, accelerating research

Dear friend,this is an open project and accepts the help of anyone willing to make positive thinking. Send your proposals (articles, cartoons, funny pictures and videos)

Editorial Staff Tel. +39 0574 442669
Promotion & Advertising Tel. +39 0574 1746090

Support and Spread the only e-magazine dedicated to good news and smiles!

Write to:

Show on your site a link to our

GOODNEWS Cerca il Meglio per te


Good News, good, news, network, positive, uplifting, l’agenzia di buone notizie e ufficio comunicati stampa online di informazione alternativa e positiva, di salute naturale ecoturismo bioedilizia, agricoltura biologica, alimentazione naturale, energie alternative fantascienza, misteri, parapsicologia, lavoro etico, autoaiuto, selfhelp, webreader,

Share This Post