Interval estimates of language divergence times

1970 ◽  
Vol 7 (03) ◽  
pp. 781-784
Author(s):  
A. J. Dobson
Keyword(s):  
Common Ancestor ◽  
Romance Languages ◽  
Divergence Times ◽  
Language Family ◽  
Interval Estimates ◽  
Numerical Example ◽  
Point Estimates ◽  
Relative Chronology ◽  
Language Divergence

It is often convenient to construct a branching diagram to represent the relationships between languages belonging to the same language family (for example, between Romance languages such as Rumanian, Italian, French and Spanish). It is desirable that the diagram should illustrate both the closeness of the relationships (that is, which pairs of languages have an immediate common ancestor and which are more remotely related) and the relative chronology of the languages. In this paper, the problem of estimating the time since two languages had a common ancestor and were the same is considered. Interval estimates are sought since, in general, consistent point estimates may be impossible; a numerical example is given to illustrate this.

Interval estimates of language divergence times

1970 ◽  
Vol 7 (3) ◽  
pp. 781-784
Author(s):  
A. J. Dobson
Keyword(s):  
Common Ancestor ◽  
Romance Languages ◽  
Divergence Times ◽  
Language Family ◽  
Interval Estimates ◽  
Numerical Example ◽  
Point Estimates ◽  
Relative Chronology ◽  
Language Divergence

It is often convenient to construct a branching diagram to represent the relationships between languages belonging to the same language family (for example, between Romance languages such as Rumanian, Italian, French and Spanish). It is desirable that the diagram should illustrate both the closeness of the relationships (that is, which pairs of languages have an immediate common ancestor and which are more remotely related) and the relative chronology of the languages. In this paper, the problem of estimating the time since two languages had a common ancestor and were the same is considered. Interval estimates are sought since, in general, consistent point estimates may be impossible; a numerical example is given to illustrate this.

scholarly journals Methodological scheme for ranking interval expert estimates of the territories hydrocarbon potential

2019 ◽  
pp. 35-39
Author(s):  
Mykhailo Popov ◽  
Oleksandr Zaitsev ◽  
Iryna Piestova
Keyword(s):  
Hydrocarbon Potential ◽  
Software System ◽  
Interval Estimates ◽  
Numerical Example ◽  
Second Stage ◽  
A Priority ◽  
Two Stages ◽  
Hydrocarbon Deposit ◽  
Interval Valued

The problem of priorities establishing for expert interval-valued estimations when experts hold the opposite opinion is considered. The whole group of expert estimates is subdivided into subgroups, first of which provides the probability of the deposit presence, and the second one provides the probability of deposit missing. A ranking methodology for interval expert estimates of the territories’ hydrocarbon potential, consisting of two stages, is proposed. At the first stage, an estimates formed by two subgroups of experts are separately aggregated by optimization. Two aggregated interval estimates of the corresponding hypotheses probabilities are obtained as a result. In the second stage, a priority estimate is determined by comparing the results. A numerical example of the test territory evaluating for a hydrocarbon deposit presence was calculated. Interval-valued estimates by five experts were used in this example for the hypotheses of hydrocarbons presence/missing. Various metrics of the distance between interval values were used to calculate persistent minima of aggregating estimates. The results of the calculations indicate the hypothesis’ priority of a hydrocarbon deposit presence within the study area. The proposed methodology for ranking interval-valued expert estimates can be used in the “Geologist’s Computer Assistant” software system.The problem of priorities establishing for expert interval-valued estimations when experts hold the opposite opinion is considered. The whole group of expert estimates is subdivided into subgroups, first of which provides the probability of the deposit presence, and the second one provides the probability of deposit missing. A ranking methodology for interval expert estimates of the territories’ hydrocarbon potential, consisting of two stages, is proposed. At the first stage, an estimates formed by two subgroups of experts are separately aggregated by optimization. Two aggregated interval estimates of the corresponding hypotheses probabilities are obtained as a result. In the second stage, a priority estimate is determined by comparing the results. A numerical example of the test territory evaluating for a hydrocarbon deposit presence was calculated. Interval-valued estimates by five experts were used in this example for the hypotheses of hydrocarbons presence/missing. Various metrics of the distance between interval values were used to calculate persistent minima of aggregating estimates. The results of the calculations indicate the hypothesis’ priority of a hydrocarbon deposit presence within the study area. The proposed methodology for ranking interval-valued expert estimates can be used in the “Geologist’s Computer Assistant” software system.

Sound Correspondence and the Comparative Study of Miao-Yao Languages (語音對應與苗瑤語比較研究)

2017 ◽  
Vol 10 (1) ◽  
pp. 95-119 ◽  
Author(s):  
Feng Wang (汪鋒) ◽  
Wen Liu (劉文)
Keyword(s):  
Genetic Relationship ◽  
Similar Pattern ◽  
Language Contact ◽  
Historical Linguistics ◽  
Common Ancestor ◽  
Language Family ◽  
Genetic Position ◽  
Long Time ◽  
The Common ◽  
The Comparative Study

Rigorous sound correspondence is fundamental to historical linguistics. It serves as a solid start in studying genetic relationship. Regarding the genetic position of Miao-Yao languages, Li (1937) proposed a hypothesis that the Sino-Tibetan language family consists of Chinese, Tibeto-Burman, Kam-Tai, and Miao-Yao. Benedict (1942; 1975) excluded Miao-Yao from the Sino-Tibetan language family since sound correspondences between Miao-Yao and Chinese were considered to be caused by language contact. The key point in this debate has been ignored for a long time: are the related morphemes proposed in this debate supported by rigorous sound correspondence? In this paper, related morphemes across 11 Miao-Yao languages have been first identified under the requirement of complete sound correspondence, and then analyzed by the Rank Method. The result of the genetic relationship between the 11 Miao-Yao languages has been confirmed. The same procedure has been applied to Sino-Miao-Yao related morphemes, and similar pattern has been found. The Sino-Miao-Yao related morphemes were recognized to be inherited from the common ancestor of Chinese and Miao-Yao. Combined with the result from the perspective of pervasive sound correspondence (Wang 2015), the proposal of a genetic relationship between Chinese and Miao-Yao has been supported. The Inexplicability Principle has been used to weaken the possibility of Sino-Miao-Yao related morphemes being induced by borrowing from Chinese to Miao-Yao, since some sound correspondences are unlikely to be explained by natural phonetic mechanisms. Moreover, related morphemes in Chinese and Miao-Yao have been examined from the perspective of Old Chinese, and such an examination also supports the hypothesis of a genetic relationship between Chinese and Miao-Yao languages. 嚴格的語音對應是歷史比較的基礎，也是判定語源關係的必要條件。在苗瑤語的語源問題研究中，李方桂（1937）提出漢藏語系四語族學說，即漢語、藏緬語、侗台語和苗瑤語。Benedict（1942、1975）則將苗瑤語從漢藏語系中劃分出去，理由是苗瑤語和漢語有對應關係的語素是由接觸造成的。苗瑤語系屬問題的爭議焦點在於苗瑤語和漢語音近義同的一批關係語素是否有嚴格的語音對應支持，然而這一問題一直以來不被重視。本文基於完全對應得到苗瑤語族內部11個語言的關係語素，隨後應用詞階法分析，結果如願所示，這11個語言之間具有發生學關係。同樣的程序應用于漢-苗瑤語關係語素，結果與上述呈現的模式相同，即這些關係語素是來自漢語和苗瑤語共同的祖語，而非語言接觸的產物。結合普遍對應的研究（Wang 2015），漢語和苗瑤語的發生學關係可以得到支持。不可釋原則也顯示漢-苗瑤語關係語素是由苗瑤語從漢語借用的可能性較小，因為二者間的部分語音對應不可能通過自然音變來解釋。此外，從上古漢語的角度對漢-苗瑤語關係語素的校驗也支持二者的同源關係。

scholarly journals Age and rate of diversification of the Hawaiian silversword alliance (Compositae)

1998 ◽  
Vol 95 (16) ◽  
pp. 9402-9406 ◽  
Author(s):  
Bruce G. Baldwin ◽  
Michael J. Sanderson
Keyword(s):  
Common Ancestor ◽  
Error Variance ◽  
Diversification Rate ◽  
Recent Common Ancestor ◽  
Divergence Times ◽  
Sequence Evolution ◽  
Most Recent Common Ancestor ◽  
History Of ◽  
Fossil Records ◽  
Fossil Data

Comparisons between insular and continental radiations have been hindered by a lack of reliable estimates of absolute diversification rates in island lineages. We took advantage of rate-constant rDNA sequence evolution and an “external” calibration using paleoclimatic and fossil data to determine the maximum age and minimum diversification rate of the Hawaiian silversword alliance (Compositae), a textbook example of insular adaptive radiation in plants. Our maximum-age estimate of 5.2 ± 0.8 million years ago for the most recent common ancestor of the silversword alliance is much younger than ages calculated by other means for the Hawaiian drosophilids, lobelioids, and honeycreepers and falls approximately within the history of the modern high islands (≤5.1 ± 0.2 million years ago). By using a statistically efficient estimator that reduces error variance by incorporating clock-based estimates of divergence times, a minimum diversification rate for the silversword alliance was estimated to be 0.56 ± 0.17 species per million years. This exceeds average rates of more ancient continental radiations and is comparable to peak rates in taxa with sufficiently rich fossil records that changes in diversification rate can be reconstructed.

scholarly journals Genomic evidence for the Old divergence of Southern European wolf populations

2020 ◽  
Vol 287 (1931) ◽  
pp. 20201206
Author(s):  
Pedro Silva ◽  
Marco Galaverni ◽  
Diego Ortega-Del Vecchyo ◽  
Zhenxin Fan ◽  
Romolo Caniglia ◽  
...  
Keyword(s):  
Canis Lupus ◽  
Common Ancestor ◽  
Demographic History ◽  
Population Decline ◽  
Divergence Times ◽  
Single Population ◽  
History Of ◽  
Fragmented Distribution ◽  
The Last Glacial Maximum ◽  
The Last Glacial

The grey wolf ( Canis lupus ) is one of the most widely distributed mammals in which a variety of distinct populations have been described. However, given their currently fragmented distribution and recent history of human-induced population decline, little is known about the events that led to their differentiation. Based on the analysis of whole canid genomes, we examined the divergence times between Southern European wolf populations and their ancient demographic history. We found that all present-day Eurasian wolves share a common ancestor ca 36 000 years ago, supporting the hypothesis that all extant wolves derive from a single population that subsequently expanded after the Last Glacial Maximum. We also estimated that the currently isolated European populations of the Iberian Peninsula, Italy and the Dinarics-Balkans diverged very closely in time, ca 10 500 years ago, and maintained negligible gene flow ever since. This indicates that the current genetic and morphological distinctiveness of Iberian and Italian wolves can be attributed to their isolation dating back to the end of the Pleistocene, predating the recent human-induced extinction of wolves in Central Europe by several millennia.

scholarly journals Paleobiolinguistics of New World Crops and the Otomanguean Language Family

2015 ◽  
Vol 6 (1) ◽  
pp. 189-191 ◽  
Author(s):  
Cecil H. Brown
Keyword(s):  
Common Bean ◽  
New World ◽  
Common Ancestor ◽  
Chili Pepper ◽  
Language Family ◽  
World Language ◽  
Way Of Life ◽  
Language Groups ◽  
The Common

Several studies recently published in Ethnobiology Letters treat respectively the paleobiolinguistics of chili pepper, manioc, maize, and the common bean in New World language families. This includes the Otomanguean family of Mexico, one of the oldest language groups of the hemisphere, whose parent language may have been spoken at the latest around 6500 years ago. This communication addresses the possibility that Otomanguean paleobiolinguistics should be considered tentative since languages of the grouping are not yet conclusively demonstrated to be descended from a common ancestor. This challenges the proposal that words for chili pepper, manioc, and maize were in vocabularies of languages spoken two thousand or more years before development of a village-farming way of life in the New World.

A Crash Course in Bayesian Inference

2015 ◽  
Author(s):  
Edward P. Herbst ◽  
Frank Schorfheide
Keyword(s):  
Decision Making ◽  
Bayesian Inference ◽  
Linear Regression ◽  
Closed Form ◽  
Posterior Distribution ◽  
Ar Model ◽  
Model Parameters ◽  
Posterior Distributions ◽  
Interval Estimates ◽  
Point Estimates

This chapter provides a self-contained review of Bayesian inference and decision making. It begins with a discussion of Bayesian inference for a simple autoregressive (AR) model, which takes the form of a Gaussian linear regression. For this model, the posterior distribution can be characterized analytically and closed-form expressions for its moments are readily available. The chapter also examines how to turn posterior distributions into point estimates, interval estimates, forecasts, and how to solve general decision problems. The chapter shows how in a Bayesian setting, the calculus of probability is used to characterize and update an individual's state of knowledge or degree of beliefs with respect to quantities such as model parameters or future observations.

Ancient divergence and biogeography of Raukaua (Araliaceae) and close relatives in the southern hemisphere

2012 ◽  
Vol 25 (6) ◽  
pp. 432 ◽  
Author(s):  
Anthony Mitchell ◽  
Rong Li ◽  
Joseph W. Brown ◽  
Ines Schönberger ◽  
Jun Wen
Keyword(s):  
New Zealand ◽  
South America ◽  
Common Ancestor ◽  
Molecular Genetic ◽  
Divergence Times ◽  
South American ◽  
The South ◽  
Representative Species ◽  
The Common ◽  
Close Relatives

Molecular genetic analyses were used to reconstruct phylogenetic relationships and estimate divergence times for Raukaua species and their close relatives. A monophyletic group identified as the ‘greater Raukaua clade’ was circumscribed, with eight representative species; its basal divergence was estimated at c. 70 Mya, possibly after Zealandia had separated from Gondwana. Raukaua is paraphyletic because of the placement of Motherwellia, Cephalaralia, Cheirodendron and Schefflera s.s. The phylogeny supports a more narrowly circumscribed Raukaua that includes the New Zealand but not the South American or Tasmanian representatives. Ancestors of the monophyletic South American and Tasmanian Raukaua and the mainland Australian Motherwellia and Cephalaralia diverged at c. 66 Mya and their current disjunction may be vicariant, with overland dispersal between Australia and South America, possibly via Antarctica. Vicariance is also a likely mechanism for divergence at c. 57 Mya of the monophyletic Motherwellia, Cephalaralia and Tasmanian Raukaua. The common ancestor of New Zealand Raukaua¸ Cheirodendron and Schefflera s.s. is inferred to have existed c. 62 Mya in New Zealand, before the marine incursions during the Oligocene, implying that New Zealand Raukaua and Schefflera s.s. survived the inundation period or speciated outside New Zealand and subsequently colonised. Ancestors of Cheirodendron split from New Zealand Raukaua c. 43 Mya and dispersed over vast expanses of the south-western Pacific to Hawaii.

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