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Evo­lu­tion


A Col­lec­tion of News by Moos


201616Jul10:57

The Cave Bear: a vegan gone extinct

Infor­ma­tion
pub­lished 16 July 2016 | mod­i­fied 16 July 2016
Archived

Cave bear from Goyet cave BelgiumSci­en­tists of the Senck­en­berg Research Insti­tute in Ger­many together with inter­na­tional part­ners have stud­ied the feed­ing habits of the extinct Cave Bear. Based on the iso­tope com­po­si­tion in the col­la­gen of the bears’ bones, they were able to show that the large mam­mals sub­sisted on a purely vegan diet. In the study, to be pub­lished in the sci­en­tific Jour­nal of Qua­ter­nary Sci­ence, the inter­na­tional team pro­poses that it was this inflex­i­ble diet that led to the Cave Bear’s extinc­tion approx­i­mately 25,000 years ago.

Today’s Brown Bears are omni­vores. Depend­ing on the time of year, they devour plants, mush­rooms, berries and small to larger mam­mals, but they will also take fish and insects. “The Cave Bear is a very dif­fer­ent story,” says Pro­fes­sor Dr. Hervé Bocherens of the Senck­en­berg Cen­ter for Human Evo­lu­tion and Palaeoen­vi­ron­ment (HEP) at the Uni­ver­sity of Tübin­gen, and he con­tin­ues to explain, “accord­ing to our newest find­ings, these extinct rel­a­tives of the Brown Bear lived on a strictly vegan diet.”

Cave bearCave Bears
Cave Bears (
Ursus spelaeus) lived in Europe dur­ing the most recent glacial period, approx­i­mately 400,000 years ago, until they became extinct about 25,000 years ago. With a length of 3.5 meters and a height of 1.7 meters at the shoul­der, these bears, which ranged from North­ern Spain to the Urals, were notice­ably larger than their modern-​day rel­a­tives. Despite their name, they did not actu­ally live in caves but only used them for hiber­na­tion. Nev­er­the­less, the occa­sional death of ani­mals in var­i­ous Euro­pean caves over sev­eral tens of thou­sands of years even­tu­ally led to enor­mous accu­mu­la­tions of bones and teeth from these large fur-​bearing ani­mals to be found in caves.

Sim­i­lar to today’s Giant Panda, the Cave Bears were there­fore extremely inflex­i­ble in regard to their food. We assume that this unbal­anced diet, in com­bi­na­tion with the reduced sup­ply of plants dur­ing the last ice age, ulti­mately led to the Cave Bear’s extinction
Pro­fes­sor Dr. Hervé Bocherens, co-​author, Senck­en­berg Cen­tre for Human Evo­lu­tion and Palaeo-​environment, Uni­ver­sity of Tübin­gen, Germany »

Sev­eral of these bones from the “Goyet Cave” in Bel­gium have now been exam­ined by the inter­na­tional team around Prof. Bocherens, with a spe­cial focus on the Cave Bear’s diet. “We were par­tic­u­larly inter­ested in what exactly the Cave Bears ate, and whether there is a con­nec­tion between their diet and their extinc­tion,” explains the bio­geol­o­gist from Tübingen.

Iso­tope study
To this end, sci­en­tists from Japan, Canada, Bel­gium and Ger­many con­ducted iso­tope stud­ies on the col­la­gen from the bears’ bones. Col­la­gen is an essen­tial organic com­po­nent of the con­nec­tive tis­sue in bones, teeth, car­ti­lage, ten­dons, lig­a­ments and the skin. The exam­i­na­tion of the iso­tope com­po­si­tion of indi­vid­ual amino acids in the col­la­gen shows that the bears lived on a strictly vegan diet. “Sim­i­lar to today’s Giant Panda, the Cave Bears were there­fore extremely inflex­i­ble in regard to their food,” adds Bocherens, and he con­tin­ues, “We assume that this unbal­anced diet, in com­bi­na­tion with the reduced sup­ply of plants dur­ing the last ice age, ulti­mately led to the Cave Bear’s extinc­tion.” Pre­vi­ously, there had been much spec­u­la­tion as to the cause of the large bears’ dis­ap­pear­ance. Was it due to increas­ing hunt­ing pres­sure from humans? The chang­ing tem­per­a­tures, or the lack of food? “We believe that the reliance on a purely vegan diet was a cru­cial rea­son for the Cave Bear’s extinc­tion,” explains Bocherens.

Dur­ing the inves­ti­ga­tion, another inter­est­ing aspect came to light. Even the col­la­gen of two Cave Bear cubs indi­cated a vegan diet – despite the fact that they were suck­led by their mother. The sci­en­tists inter­pret this find­ing as a reflec­tion of the nurs­ing female’s diet.

We now intend to exam­ine addi­tional Cave Bear bones from var­i­ous Euro­pean loca­tions with this new method, as well as con­duct­ing con­trolled feed­ing exper­i­ments with mod­ern bears, in order to fur­ther solid­ify our propo­si­tion,” adds Bocherens by way of a preview.


(Source: Senck­en­berg press release, 15.07.2016)


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Tiger range countries map

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

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