scholarly journals Inter-glacial isolation caused divergence of cold-adaptedspecies: the case of the snow partridge

2021 ◽  
Author(s):  
Hongyan Yao ◽  
Yanan Zhang ◽  
Zhen Wang ◽  
Gaoming Liu ◽  
Quan Ran ◽  
...  
Keyword(s):  
Population Size ◽  
Hengduan Mountains ◽  
Glacial Period ◽  
Ecological Niche Models ◽  
Effective Population ◽  
Cold Adapted ◽  
Climatic Oscillations ◽  
Glacial Periods ◽  
High Elevations

Abstract Deciphering the role of climatic oscillations in species divergence helps us understand the mechanisms that shape global biodiversity. The cold-adapted species may have expanded their distribution with the development of glaciers during glacial period. With the retreat of glaciers, these species were discontinuously distributed in the high-altitude mountains and isolated by geographical barriers. However, the study that focuses on the speciation process of cold-adapted species is scant. To fill this gap, we combined population genetic data and ecological niche models (ENMs) to explore divergence process of snow partridge (Lerwa lerwa). Lerwa lerwa is a cold-adapted bird that is distributed from 4,000 to 5,500 m. We found 2 genetic populations within L. lerwa, and they diverged from each other at about 0.40–0.44 million years ago (inter-glacial period after Zhongliangan glaciation). The ENMs suggested that L. lerwa expanded to the low elevations of the Himalayas and Hengduan mountains during glacial period, whereas it contracted to the high elevations, southern of Himalayas, and Hengduan mountains during inter-glacial periods. Effective population size trajectory also suggested that L. lerwa expanded its population size during the glacial period. Consistent with our expectation, the results support that inter-glacial isolation contributed to the divergence of cold-adapted L. lerwa on Qinghai-Tibetan Plateau. This study deepens our understanding of how climatic oscillations have driven divergence process of cold-adapted Phasianidae species distributed on mountains.

Glaciation of the Torngat Mountains, Northern Labrador

ARCTIC ◽  
1957 ◽  
Vol 10 (2) ◽  
pp. 66 ◽  
Author(s):  
J.D. Ives
Keyword(s):  
North America ◽  
Ice Sheet ◽  
Field Work ◽  
Glacial Period ◽  
Large Area ◽  
International Union ◽  
Northeastern North America ◽  
Glacial Periods

Considers role of these mountains in glaciation of Labrador-Ungava, assessing particularly events in late-Wisconsin times with respect to final disappearance of both continental and local ice masses. Conflicting theories are discussed, and evidence presented, based on physiography and findings from summer 1956 field work, including unmistakable erratics on summits at 4,000-5,000 ft. The highest summits were completely submerged by eastward moving continental ice during the Wisconsin glaciation; local glaciers never reached significant dimensions; rapid melting in situ of thick masses of ice occurred during the final Wisconsin stages. Two or three separate glacial periods are recognized from the morphology of the area. Instantaneous glaciation of a large area of the Labrador-Ungava Plateau probably initiated a continental ice sheet in northeastern North America at the onset of each glacial period. Also pub. in International Union of Geodesy and Geophysics, Association of Scientific Hydrology, 11th assembly report of proceedings 1958, v. 4, p. 372-86.

A DIRECT ASSESSMENT OF THE ROLE OF GENETIC DRIFT IN DETERMINING ALLELE FREQUENCY VARIATION IN POPULATIONS OF EUPHYDRYAS EDITHA

Genetics ◽  
1985 ◽  
Vol 110 (3) ◽  
pp. 495-511
Author(s):  
Laurence D Mueller ◽  
Bruce A Wilcox ◽  
Paul R Ehrlich ◽  
David G Heckel ◽  
Dennis D Murphy
Keyword(s):  
Population Size ◽  
Effective Population Size ◽  
Genetic Drift ◽  
Allele Frequencies ◽  
Frequency Variation ◽  
Effective Population ◽  
Variable Environment ◽  
Euphydryas Editha ◽  
Two Populations

ABSTRACT Estimates of allele frequencies at six polymorphic loci were collected over eight generations in two populations of Euphydryas editha. We have estimated, in addition, the effective population size for each generation for both populations with results from mark-recapture and other field data. The variation in allele frequencies generated by random genetic drift was then studied using computer simulations and our direct estimates of effective population size. Substantial differences between observed values and computer-generated expected values assuming drift alone were found for three loci (Got, Hk, Pgi) in one population. These observations are consistent with natural selection in a variable environment.

The Role of Dispersal in Structuring the Chitwan Tiger Population

Behaviour ◽  
1993 ◽  
Vol 124 (3-4) ◽  
pp. 165-195 ◽  
Author(s):  
JAMES L. DAVID Smith
Keyword(s):  
Social Interactions ◽  
Population Size ◽  
National Park ◽  
Genetic Variance ◽  
Effective Population ◽  
The World ◽  
Chitwan National Park ◽  
Tiger Population ◽  
Stochastic Events

AbstractDispersal in tigers was studied in Royal Chitwan National Park, Nepal. Thirty six adult and young were studied to monitor movements and social interactions relative to dispersal. Fourteen subadults were followed from before their dispersal until they died or established post-dispersal territories. Subadult tigers became semi-independent of their mother when her next litter was born. They usually remained within her natal area until the subsequent litter began to move with her at about 2 mos of age. Animals dispersed between 19 and 28 mos. Males dispersed farther than females and settled in poorer habitat. Three of 4 females settled adjacent to their mothers; in two cases the mother shifted her territory allowing the daughter to take over a large portion of the mother's former territory. Wounds on young prior to dispersal indicated that aggression prompted dispersal. Fjghts were observed between dispersers and residents. After fights, dispersers always left the resident's area. All 4 dispersing females established breeding territories. Females settled next to their mothers tending to reduce the genetic variance of a male's offspring. Eight of 10 males became localized in temporary, post-dispersal territories; 4 of the 8 survived. Two males died of poisoning and 2 from intrasexual aggression. Surviving males either expanded temporary territories or shifted to new areas to establish breeding territories. The Chitwan tigers are an isolated remnant of a population once continuous across the lowlands of Nepal. Effective population size was estimated to be <30 animals. Tigers did not disperse across cultivated areas but did travel through degraded forest habitat. No animal dispersed outside the Chitwan region and there appear to be effective barriers separating Chitwan from the two nearest populations 150 and 250 kms distant. The Chitwan population is probably one of the largest tiger populations remaining in the world. Isolation and small size threaten these populations with stochastic events that may lead to further reduction in population size.

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