scholarly journals Unravelling the evolutionary history of Eucalyptus cordata (Myrtaceae) using molecular markers

2014 ◽  
Vol 62 (2) ◽  
pp. 114 ◽  
Author(s):  
Peter A. Harrison ◽  
Rebecca C. Jones ◽  
René E. Vaillancourt ◽  
Robert J. E. Wiltshire ◽  
Brad M. Potts

We studied the evolutionary processes shaping the genetic diversity in the naturally fragmented Eucalyptus cordata, a rare homoblastic tree endemic to the island of Tasmania. A genome-wide scan showed that E. cordata and the endangered heteroblastic E. morrisbyi were closely related, suggesting a neotenous origin of E. cordata from an endemic heteroblastic ancestor. Bayesian cluster analysis based on nuclear microsatellites assayed in 567 E. cordata and E. morrisbyi individuals revealed five genetic clusters. Two clusters comprised populations that correspond to putative ancestral gene pools linking E. cordata and E. morrisbyi. Another cluster included populations that transgressed the drowned Derwent River valley, suggestive of a wider glacial distribution. However, the majority of individuals occurred in the two genetic clusters distributed in the south-west and north-east of the range of E. cordata. The elevated genetic diversity in populations comprising these clusters suggests that they represent two recently fragmented cores of the distribution. Genetic evidence suggests that the newly described, localised E. cordata subspecies quadrangulosa has been recently selected from within the morphologically diverse, south-western cluster. We argue that multiple phases of isolation and drift have led to the contemporary pattern of molecular variation and the scattering of relictual and more recently derived populations across the species distribution.

2021 ◽  
Vol 7 (13) ◽  
pp. eabe4414
Author(s):  
Guido Alberto Gnecchi-Ruscone ◽  
Elmira Khussainova ◽  
Nurzhibek Kahbatkyzy ◽  
Lyazzat Musralina ◽  
Maria A. Spyrou ◽  
...  

The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules.


2006 ◽  
Vol 38 (7) ◽  
pp. 794-800 ◽  
Author(s):  
Anelia Horvath ◽  
Sosipatros Boikos ◽  
Christoforos Giatzakis ◽  
Audrey Robinson-White ◽  
Lionel Groussin ◽  
...  

Genetics ◽  
2013 ◽  
Vol 196 (3) ◽  
pp. 829-840 ◽  
Author(s):  
Timothy M. Beissinger ◽  
Candice N. Hirsch ◽  
Brieanne Vaillancourt ◽  
Shweta Deshpande ◽  
Kerrie Barry ◽  
...  

1999 ◽  
Vol 17 (S1) ◽  
pp. S49-S54 ◽  
Author(s):  
J.S. Barnholtz ◽  
M. de Andrade ◽  
G.P. Page ◽  
T.M. King ◽  
L.E. Peterson ◽  
...  

2007 ◽  
Vol 144B (2) ◽  
pp. 193-199 ◽  
Author(s):  
M.A. Escamilla ◽  
A. Ontiveros ◽  
H. Nicolini ◽  
H. Raventos ◽  
R. Mendoza ◽  
...  

1999 ◽  
Vol 17 (S1) ◽  
pp. S621-S626
Author(s):  
Li Hsu ◽  
Corinne Aragaki ◽  
Filemon Quiaoit ◽  
Xiangjing Wang ◽  
Xiubin Xu ◽  
...  

2018 ◽  
Vol 116 (1) ◽  
pp. 187-192 ◽  
Author(s):  
Tin Yau Pang ◽  
Martin J. Lercher

Even closely related prokaryotes often show an astounding diversity in their ability to grow in different nutritional environments. It has been hypothesized that complex metabolic adaptations—those requiring the independent acquisition of multiple new genes—can evolve via selectively neutral intermediates. However, it is unclear whether this neutral exploration of phenotype space occurs in nature, or what fraction of metabolic adaptations is indeed complex. Here, we reconstruct metabolic models for the ancestors of a phylogeny of 53Escherichia colistrains, linking genotypes to phenotypes on a genome-wide, macroevolutionary scale. Based on the ancestral and extant metabolic models, we identify 3,323 phenotypic innovations in the history of theE. coliclade that arose through changes in accessory genome content. Of these innovations, 1,998 allow growth in previously inaccessible environments, while 1,325 increase biomass yield. Strikingly, every observed innovation arose through the horizontal acquisition of a single DNA segment less than 30 kb long. Although we found no evidence for the contribution of selectively neutral processes, 10.6% of metabolic innovations were facilitated by horizontal gene transfers on earlier phylogenetic branches, consistent with a stepwise adaptation to successive environments. Ninety-eight percent of metabolic phenotypes accessible to the combinedE. colipangenome can be bestowed on any individual strain by transferring a single DNA segment from one of the extant strains. These results demonstrate an amazing ability of theE. colilineage to adapt to novel environments through single horizontal gene transfers (followed by regulatory adaptations), an ability likely mirrored in other clades of generalist bacteria.


2003 ◽  
Vol 123A (2) ◽  
pp. 140-147 ◽  
Author(s):  
Diego F. Wyszynski ◽  
Hasan Albacha-Hejazi ◽  
Mohammed Aldirani ◽  
Moustafa Hammod ◽  
Hikmat Shkair ◽  
...  

2009 ◽  
Vol 20 (6) ◽  
pp. 386-392 ◽  
Author(s):  
Rongrong Chen ◽  
Jun Ren ◽  
Wanbo Li ◽  
Xiang Huang ◽  
Xueming Yan ◽  
...  

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