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Evo­lu­tion


A Col­lec­tion of News by Moos


201622Oct11:02

New species are evolv­ing but that’s not good news

Infor­ma­tion
pub­lished 22 Octo­ber 2016 | mod­i­fied 22 Octo­ber 2016
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The London underground mosquitoSpecies across the world are rapidly going extinct due to human activ­i­ties, but humans are also caus­ing rapid evo­lu­tion and the emer­gence of new species. A study pub­lished on 29 June sum­marises the causes of man-​made spe­ci­a­tion, and dis­cusses why newly evolved species can­not sim­ply replace extinct wild species. The study was led by the Cen­ter for Macro­e­col­ogy, Evo­lu­tion and Cli­mate at the Uni­ver­sity of Copenhagen.

A grow­ing num­ber of exam­ples show that humans not only con­tribute to the extinc­tion of species but also drive evo­lu­tion, and in some cases the emer­gence of entirely new species. This can take place through mech­a­nisms such as acci­den­tal intro­duc­tions, domes­ti­ca­tion of ani­mals and crops, unnat­ural selec­tion due to hunt­ing, or the emer­gence of novel ecosys­tems such as the urban environment.

Although tempt­ing to con­clude that human activ­i­ties thus attribute to as well as deplete global bio­di­ver­sity, the authors stress that extinct wild species can­not sim­ply be replaced with newly evolved ones, and that nature con­ser­va­tion remains just as urgent.

The prospect of ‘arti­fi­cially’ gain­ing novel species through human activ­i­ties is unlikely to elicit the feel­ing that it can off­set losses of ‘nat­ural’ species. Indeed, many peo­ple might find the prospect of an arti­fi­cially bio­di­verse world just as daunt­ing as an arti­fi­cially impov­er­ished one
Joseph Bull, lead author, Post­doc, Cen­ter for Macro­e­col­ogy, Evo­lu­tion and Cli­mate, Uni­ver­sity of Copenhagen »

Humans cre­ated the ‘Lon­don Under­ground mos­quito’
The study which was car­ried out in col­lab­o­ra­tion with the Uni­ver­sity of Queens­land was pub­lished on 29 June in Pro­ceed­ings of Royal Soci­ety B. It high­lights numer­ous exam­ples of how human activ­i­ties influ­ence species’ evo­lu­tion. For instance: as the com­mon house mos­quito adapted to the envi­ron­ment of the under­ground rail­way sys­tem in Lon­don, it estab­lished a sub­ter­ranean pop­u­la­tion. Now named the ‘Lon­don Under­ground mos­quito’, it can no longer inter­breed with its above ground coun­ter­part and is effec­tively thought to be a new species.

We also see exam­ples of domes­ti­ca­tion result­ing in new species. Accord­ing to a recent study, at least six of the world’s 40 most impor­tant agri­cul­tural crops are con­sid­ered entirely new” explains Joseph Bull.

Fur­ther­more, unnat­ural selec­tion due to hunt­ing can lead to new traits emerg­ing in ani­mals, which can even­tu­ally lead to new species, and delib­er­ate or acci­den­tal relo­ca­tion of species can lead to hybridiza­tion with other species. Due to the lat­ter, more new plant species in Europe have appeared than are doc­u­mented to have gone extinct over the last three cen­turies. It also means that we should be cau­tious about rewil­d­ing land­scapes as a con­ser­va­tion measure.

(click ‘cc’ for subtitles)

We have to decide what kind of nature we want
Although it is not pos­si­ble to quan­tify exactly how many spe­ci­a­tion events have been caused through human activ­i­ties, the impact is poten­tially con­sid­er­able, the study states.

In this con­text, ‘num­ber of species’ becomes a deeply unsat­is­fac­tory mea­sure of con­ser­va­tion trends, because it does not reflect many impor­tant aspects of bio­di­ver­sity. Achiev­ing a neu­tral net out­come for species num­bers can­not be con­sid­ered accept­able if weigh­ing wild fauna against rel­a­tively homo­ge­neous domes­ti­cated species. How­ever, con­sid­er­ing spe­ci­a­tion along­side extinc­tion may well prove impor­tant in devel­op­ing a bet­ter under­stand­ing of our impact upon global bio­di­ver­sity. We call for a dis­cus­sion about what we, as a soci­ety, actu­ally want to con­serve about nature”, says Asso­ciate Pro­fes­sor Mar­tine Maron from the Uni­ver­sity of Queensland.

Researchers do agree that cur­rent extinc­tion rates may soon lead to a 6th period of mass extinc­tion. Since the last Ice Age, 11.500 years ago, it is esti­mated that 255 mam­mal and 523 bird species has gone extinct, often due to human activ­ity. In the same period, humans have relo­cated almost 900 known species and domes­ti­cated more than 470 ani­mals and close to 270 plant species.

(Source: Cen­ter for Macro­e­col­ogy, Evo­lu­tion and Cli­mate press release, 29.06.2016)


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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