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A more robust EDGE

By on August 24, 2011 in EDGE Updates, Mammals, Uncategorized

Last week a new paper was published by researchers at ZSL which included a new EDGE mammals list. The list is the result of updated information and a strengthening of the methods used to calculate EDGE rank. A species’ EDGE (Evolutionarily Distinct and Globally Endangered) score is calculated by combining a measure of the evolutionary history of that species and its global endangerment status (Critically Endangered, Endangered or Vulnerable on the IUCN Red List); in order to produce a list of species which have few or no relatives in the tree or life and are in need of urgent conservation. Click here to take a closer look at EDGE Science.

The paper and its updated list of mammals evaluates the effect of an updated phylogenetic tree, the discovery of new mammal species, changes to global IUCN Red List status, and trials a new technique for dealing with polytomies (unresolved evolutionary relationships between species ) that better represents their implied uncertainty.

“When we’re making choices about which species we should focus our limited conservation resources and attention on, we must do so with the best available information, and most robust scientific decision making tools.  Even in well studied groups like mammals, our knowledge of the relationships between species, and the risk of extinction they face, develops rapidly.  Our updated technique for discerning EDGE species allows us to better account for this new information and demonstrates how robust our prioritisation technique is to the inevitable vagaries of changing knowledge on the species about which we are so concerned.

Given that large numbers of evolutionarily distinct species are inadequately served by existing conservation strategies, the priority must be to fast-track the necessary Red Listing and phylogeny-building exercises for new groups of species, to ensure that an imminent loss of large quantities of our global evolutionary heritage does not occur” Said Dr. Ben Collen lead author of the publication.

As a result of the updated method in EDGE prioritization, the list of top 100 mammal species has undergone only a few changes, with six species dropping out of the top 100, replaced by six formerly lower ranked species.

Species moved into the EDGE top 100 mammals:

Ethiopian water mouse (Nilopegamys plumbeus)

Sclater’s Shrew (Sorex sclateri)

San Cristobal Shrew (Sorex stizodon)

Large Rock Rat (Cremnomys elvira)

Kondana soft-furred Rat (Millardia kondana)

Dinagat bushy-tailed Cloud Rat (Crateromys australis)

The following EDGE species have move down in ranking as a result of the changes in species knowledge, but most remain just shy of the top 100 with the exception of the  Brown-headed Spider Monkey:

Marley’s Golden Mole (Amblysomus marleyi)

Brown-headed Spider Monkey (Ateles fusciceps)

Red Panda (Ailurus fulgens)

Lorenz Von Liburnau’s Woolly Lemur (Avahi occidentalis)

Blunt-eared Bat (Tomopeas ravus)

Banded Hare Wallaby (Lagostrophus fasciatus)

Read Investing in evolutionary history: implementing a phylogenetic approach for mammal conservation in Philosophical Transaction of the Royal Society B. at Https://

Here at EDGE we never tire of staying at the forefront of conservation science and action .