enzh-TWfrderues

Evo­lu­tion


A Col­lec­tion of News by Moos


201726Mar08:13

Tool-​using Sea otters not closely related and ahead of dol­phins using tools

Infor­ma­tion
pub­lished 26 March 2017 | mod­i­fied 26 March 2017
Archived

Sea otter using toolTool use by sea otters to break open well-​armoured food is not nec­es­sar­ily a fam­ily mat­ter, accord­ing to a new study pub­lished this week by the Smith­son­ian Con­ser­va­tion Biol­ogy Insti­tute (SCBI) and part­ners. Unlike pre­vi­ous research that has found that a group of tool-​using Indio-​Pacific bot­tlenose dol­phins share a com­mon genetic lin­eage, this study found that tool use in sea otters is ubiq­ui­tous and actu­ally has lit­tle to do with genetic ties.

Sea otters and bot­tle­neck dol­phins both use tools and they are eco­log­i­cally sim­i­lar, so we thought they might have a sim­i­lar genetic pat­tern,” said Kather­ine Ralls, sci­en­tist emer­i­tus at SCBI’s Cen­ter for Con­ser­va­tion Genomics and lead author of the paper, pub­lished on 22 March in the jour­nal Biol­ogy Let­ters. “Sur­pris­ingly, what we dis­cov­ered is that sea otters that most fre­quently use tools are no more related to each other than to the pop­u­la­tion as a whole.”

Although not all indi­vid­u­als in a pop­u­la­tion use tools, sea otters com­monly use rocks or other hard objects to break open their meals – marine snails, crabs and abalones, for exam­ple. The paper’s authors included in the study indi­vid­ual otters they had observed using tools for at least 40 per­cent of cap­tured prey. SCBI’s Cen­ter for Con­ser­va­tion Genomics analysed the genetic infor­ma­tion col­lected from indi­vid­ual sea otters along the Cal­i­for­nia coast between 2000 and 2014.

DNA analy­sis is crit­i­cal to bet­ter under­stand­ing our nat­ural world and our world’s nat­ural his­tory, in this case help­ing us get a bet­ter grasp on the little-​known world of tool use in marine ani­mals,” said Nancy Rotzel McIn­er­ney, man­ager of SCBI’s Cen­ter for Con­ser­va­tion Genomics lab­o­ra­tory and co-​author on the paper. “Our lab spe­cial­izes in obtain­ing large amounts of genetic infor­ma­tion from small amounts of tis­sue, hair or scat sam­ples from rare and endan­gered species that are dif­fi­cult to cap­ture. In this case, we were able to obtain a whole lot of infor­ma­tion from a small sam­ple taken when indi­vid­u­als were tagged for identification.”

Accord­ing to the study’s authors, the dif­fer­ence in genetic pat­terns between tool-​using otters and tool-​using dol­phins may be the result of how long each species has been using tools. While tool use in dol­phins appears to have devel­oped within the past 200 years, sea otters may have been using tools for many thou­sands – or even mil­lions – of years and may there­fore be more innately pre­dis­posed to do so. Researchers aim to con­firm how long sea otters have been using tools by exam­in­ing fos­sil sea otters for the kinds of phys­i­cal indi­ca­tions of tool use seen in mod­ern otters.

Con­ser­va­tion sta­tus
The Inter­na­tional Union for Con­ser­va­tion of Nature Red List of Threat­ened Species clas­si­fies sea otters (Enhy­dra lutris) as Endan­gered. Only 2,000 sea otters existed world­wide by the end of the com­mer­cial fur trade in 1911, and the pop­u­la­tion has been rebound­ing since, though the species still faces var­i­ous threats, includ­ing attacks by sharks and oil spills.

(Source: Smith­son­ian News­desk news release, 22.03.2017)


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.
Fol­low me on: