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Evo­lu­tion


A Col­lec­tion of News by Moos


Evo­lu­tion in the news, arti­cles that stood out and caught my attention.

Moos

201902Feb15:25

How new pri­mates and other species emerge

Infor­ma­tion
pub­lished 02 Feb­ru­ary 2019 | mod­i­fied 02 Feb­ru­ary 2019
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Inter­na­tional research team recon­structs the evo­lu­tion­ary his­tory of baboons

Baboon species distributionBaboon (Papio) species dis­tri­b­u­tion. (A) The appear­ance and cur­rent dis­tri­b­u­tion of each baboon species, and the loca­tions of three well-​documented active hybrid zones are also shown. x1: hybrid zone between P. hamadryas and P. anu­bis, x2: hybrid zone between P. cyno­cephalus and P. anu­bis, x3: hybrid zone between P. kin­dae and P. ursi­nus. Draw­ings of each species by S. Nash. (B) Dis­tin­guish­ing fea­tures of Papio species.
Rogers et al., 2019. The com­par­a­tive genomics and com­plex pop­u­la­tion his­tory of Papio baboons. Cre­ative Com­mons Attri­bu­tion Non­Com­mer­cial License 4.0 (CC BY-​NC)

Life on earth is com­plex and diverse. In the course of evo­lu­tion, more and more new species have emerged that are adapted to con­stantly chang­ing envi­ron­ments. Using mod­ern genetic analy­ses, researchers can now fully deci­pher the genetic infor­ma­tion of organ­isms in order to bet­ter under­stand their evo­lu­tion­ary his­to­ries and adap­ta­tions. Under the lead­er­ship of the Human Genome Sequenc­ing Cen­ter at Bay­lor Col­lege of Med­i­cine, USA, an inter­na­tional team of researchers, includ­ing sci­en­tists from the Ger­man Pri­mate Cen­ter (DPZ) – Leib­niz Insti­tute for Pri­mate Research, has recon­structed the phy­lo­ge­netic tree of the six African baboon species. The genetic infor­ma­tion of baboons also pro­vided clear indi­ca­tions that genes were exchanged between the species, i.e. that the species hybridized. The study, pub­lished on 30 Jan­u­ary in the jour­nal Sci­ence Advances, sheds new light on the fun­da­men­tal bio­log­i­cal processes that pro­duce new species. Since the baboons evolved at about the same time and in the same habi­tats as humans, the results of the study also allow con­clu­sions about the evo­lu­tion­ary his­tory of early human species.

Baboons are Old World mon­keys and the six dif­fer­ent baboon species are wide­spread in sub-​Saharan Africa. They are well stud­ied for their mor­phol­ogy, behav­iour and ecol­ogy. So far, how­ever, lit­tle has been known about their genetic adap­ta­tions and evo­lu­tion­ary history.

To inves­ti­gate these ques­tions in detail, the researchers sequenced the com­plete genomes of the six species. By com­par­ing the genomes and apply­ing dif­fer­ent phy­lo­ge­netic tree mod­els, the sci­en­tists detected that, in addi­tion to spe­ci­a­tion by lin­eage split­ting, spe­ci­a­tion by hybridiza­tion and asso­ci­ated gene exchange also occurred.

Baboon phylogenetic treeEvo­lu­tion­ary and demo­graphic his­tory for Papio baboons.
(A) Analy­ses using f-​statistics indi­cate that P. kin­dae was formed via input from both a south­ern clade lin­eage and a north­ern clade lin­eage, with con­tri­bu­tions esti­mated to be 52 and 48%. P. papio is inferred to have been pro­duced through 10% intro­gres­sion from an uniden­ti­fied ancient north­ern lin­eage into a pop­u­la­tion related to P. anu­bis. Dates for diver­gence and admix­ture events were inferred through CoalHMM, and inter­nal nodes rep­re­sent­ing those diver­gence or admix­ture events are labeled A through K. Our analy­ses of asym­met­ric hap­lo­type shar­ing also inferred admix­ture from P. cyno­cephalus into P. anu­bis approx­i­mately 21 gen­er­a­tions ago.
Rogers et al., 2019. The com­par­a­tive genomics and com­plex pop­u­la­tion his­tory of Papio baboons. Cre­ative Com­mons Attri­bu­tion Non­Com­mer­cial License 4.0 (CC BY-​NC)

The Kinda baboon, a species of baboon endemic to south­ern Africa, is most likely a prod­uct of the fusion of two ances­tral baboon lin­eages,” explains Chris­t­ian Roos, a sci­en­tist in the Pri­mate Genet­ics Lab­o­ra­tory at the Ger­man Pri­mate Cen­ter and one of the authors of the study. “We were also able to iden­tify genetic traits that could not be assigned to any of the baboon species liv­ing today, indi­cat­ing that gene flow from an extinct baboon lin­eage, a so-​called ghost line occurred.”

Hybridiza­tion between baboon species can still be observed today in areas where species’ ranges meet. Since baboons evolved in the same sub-​Saharan habi­tats as humans about two mil­lion years ago, they pro­vide an excel­lent anal­o­gous model for the evo­lu­tion­ary his­tory of the genus Homo, of which mod­ern humans are the only species which has survived.

Our col­leagues at the Max Planck Insti­tute for Evo­lu­tion­ary Anthro­pol­ogy in Leipzig and in other lab­o­ra­to­ries have already shown that mod­ern humans hybridized with other species such as Nean­derthals or Deniso­vans,” sum­ma­rizes Diet­mar Zin­ner, sci­en­tist in the Cog­ni­tive Ethol­ogy Lab­o­ra­tory at the DPZ and also one of the authors. “In con­trast to humans, whose sis­ter species are now extinct, hybridiza­tion and genetic exchange among baboon species can still be stud­ied today. This gives us a bet­ter under­stand­ing of the evo­lu­tion of our own species”.

Baboons are not only a model for hybridiza­tion stud­ies. They also serve as an excel­lent com­par­a­tive model for stud­ies of the impact of his­tor­i­cal cli­mate and envi­ron­men­tal changes on the evo­lu­tion of savan­nah pri­mates, includ­ing humans.

(Source: Ger­man Pri­mate Cen­ter (DPZ) press release, 30.01.2019)


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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