منابع مشابه
How many species are there?
'How many species are there' is a question receiving more attention from biologists and reasons for this are suggested. Different methods of answering this question are examined and include: counting all species; extrapolations from known faunas and regions; extrapolations from samples; methods using ecological models; censusing taxonomists' views. Most of these methods indicate that global tot...
متن کاملHow Many Species of Algae Are There?
Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on-line taxonomic database AlgaeBase (http://www.algaebase.org). Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the va...
متن کاملHow many species are there on Earth?
This article surveys current answers to the factual question posed in the title and reviews the kinds of information that are needed to make these answers more precise. Various factors affecting diversity are also reviewed. These include the structure of food webs, the relative abundance of species, the number of species and of individuals in different categories of body size, along with other ...
متن کاملHow many species of prokaryotes are there?
T microorganisms classified in the two prokaryotic domains of the tree of life, Bacteria and Archaea, possess immense metabolic diversity, and their activities are critical in processes ranging from sewage treatment to regulating the composition of the atmosphere. Especially in light of the rate of modern climate change, it is essential to understand how microbial communities affect ecosystem f...
متن کاملHow many species of giraffe are there?
In a recent paper in Current Biology, Fennessy and colleagues [1] conclude that there are four species of giraffe and that their numbers are declining in Africa. Giraffes (Giraffa camelopardalis) are presently classified as one species, with nine subspecies, which are considered 'Vulnerable' on the IUCN Red List [2]. The present consensus of one species divided into nine subspecies has previous...
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ژورنال
عنوان ژورنال: Biodiversity and Conservation
سال: 1994
ISSN: 0960-3115,1572-9710
DOI: 10.1007/bf02291892