A Col­lec­tion of News by Moos


The big­ger the evo­lu­tion­ary jump, the more lethal cross-​species dis­eases could be

pub­lished 20 April 2019 | mod­i­fied 20 April 2019

Zebra equine herpes virus jumped to polar bear in Wuppertal ZooChang­ing cli­mate and ecosys­tems, and zoos, may cause more and dif­fer­ent species to inter­act. This could increase the emer­gence of dis­eases in new host species when dis­eases cross the species bar­rier. When the host species between which the pathogen jumps are evo­lu­tion­ary less related, the dis­ease could be more lethal in the new host accord­ing a recent publication.

Some dis­eases which are fatal in one species can cause only mild dis­com­fort in another – but it’s hard for sci­en­tists to pre­dict how lethal a dis­ease will be if it leaps across species.

How­ever, a new paper pub­lished online on 29 March in the jour­nal PNAS indi­cates that the evo­lu­tion­ary rela­tion­ship between infected hosts can pre­dict the impact of diseases.

Cana­dian researchers used data from the World Organ­i­sa­tion for Ani­mal Health (OIE) to track dis­eases in domes­ti­cated mam­mals, trac­ing their paths and out­comes across the world.

The big­ger the evo­lu­tion­ary jump between species, the more likely the dis­ease could be lethal in its new host.

Jonathan Davies, co-​author, Botany, For­est, and Con­ser­va­tion Sci­ences & Bio­di­ver­sity Research Cen­tre, Uni­ver­sity of British Colum­bia, Canada; African Cen­tre for DNA Bar­cod­ing, Uni­ver­sity of Johan­nes­burg, South Africa

A dis­ease jump­ing from a buf­falo to a cow is mak­ing a short evo­lu­tion­ary jump, and is less likely to be fatal. A dis­ease jump­ing from a buf­falo to a cat involves a larger evo­lu­tion­ary jump and a higher chance of death. Luck­ily, this lethal­ity may cause the dis­ease to spread poorly amongst its new hosts.

Nev­er­the­less, such infec­tions are a con­cern. Many dis­eases are trans­mit­ted between domes­ti­cated ani­mals, wildlife and humans. A dis­ease that is less lethal, but easy to spread, could be even more prob­lem­atic than one with a high mor­tal­ity rate.

With the world’s ecosys­tems under­go­ing rapid trans­for­ma­tions and cli­mate change alter­ing species’ ranges, dif­fer­ent ani­mals are com­ing in con­tact for the first time. This may pro­mote the emer­gence of dis­eases in new hosts,” says Maxwell Far­rell, the lead author of the study who con­ducted the research while at McGill Uni­ver­sity. “Pre­dict­ing the out­come of these inter­ac­tions will pose a major challenge.”

The biol­o­gists hope to expand their research, look­ing at more species, includ­ing humans, to cre­ate a data­base of infec­tion outcomes.

We shouldn’t worry about the num­ber of dis­eases we have, we should be wor­ried about how vir­u­lent they are – whether they are in wildlife, domes­ti­cated ani­mals or humans,” con­cludes Davies.

(Source: the Uni­ver­sity of British Colum­bia media release, 28.03.2019)

UN Biodiversity decade

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
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