scholarly journals Convergence of knowledge in a stochastic cultural evolution model with population structure, social learning and credibility biases

Author(s):  
Sylvain Billiard ◽  
Maxime Derex ◽  
Ludovic Maisonneuve ◽  
Thomas Rey

Understanding how knowledge emerges and propagates within groups is crucial to explain the evolution of human populations. In this work, we introduce a mathematically oriented model that draws on individual-based approaches, inhomogeneous Markov chains and learning algorithms, such as those introduced in [F. Cucker and S. Smale, On the mathematical foundations of learning, Bull. Amer. Math. Soc. 39 (2002) 1–49; F. Cucker, S. Smale and D. X. Zhou, Modeling language evolution, Found. Comput. Math. 4 (2004) 315–343]. After deriving the model, we study some of its mathematical properties, and establish theoretical and quantitative results in a simplified case. Finally, we run numerical simulations to illustrate some properties of the model. Our main result is that, as time goes to infinity, individuals’ knowledge can converge to a common shared knowledge that was not present in the convex combination of initial individuals’ knowledge.

2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.


2001 ◽  
pp. 225-249 ◽  
Author(s):  
Jose Luis Fernandez Aleman ◽  
Ambrosio Toval Alvarez

Despite the fact that the Unified Modeling Language (UML) has been adopted by the Object Management Group (OMG2 ) as the standard notation for use in Object-Oriented (OO) Systems Development, it still does not have a truly formal semantics. There is currently much effort directed towards formalizing particular aspects or models of UML. However, the literature gives little insight into the appropriate strategy for tackling this problem within an integrated basis including the language evolution. This chapter identifies and discusses three feasible strategies which can be applied to formalize UML. One of these strategies is selected to underpin the four-layer architecture on which UML is based. The approach is based on the soundness of algebraic specification theory, which, in addition, provides suitable theorem-proving capabilities for exploiting the UML formal model obtained. The formal models proposed are specified using an executable algebraic specification language called Maude.


1985 ◽  
Vol 17 (1) ◽  
pp. 97-106 ◽  
Author(s):  
John H. Relethford

SummaryA method is presented for examining the relationship between effective population size and accumulated random inbreeding in human populations. For a set of populations, the inverse of inbreeding is regressed on effective population size using a linear regression model. This procedure allows testing of several hypotheses regarding the common and unique influences on population structure. Deviations from the expected curve suggest demographic or historical change. This method is applied to surname data from nine Irish isolates. The results show that the method is very useful in assessing differential influences on population structure.


2020 ◽  
Vol 10 (2) ◽  
pp. 188-229
Author(s):  
Gareth Roberts ◽  
Betsy Sneller

Abstract Half a century ago, Uriel Weinreich, William Labov, and Marvin Herzog laid out a programmatic vision for the study of language change. This included establishing five fundamental problems for the field and a radical shift from a focus on idiolects to a focus on population-level change (grounded in their concept of orderly heterogeneity). They also expressed an explicit desire to see an integrated evolutionary study of language change. In spite of this, the newer fields of language evolution and cultural evolution make little contact with the field of sociolinguistics that emerged out of their work. Here we lay out a program, grounded in their five problems, for a more integrated future. We situate each problem in modern sociolinguistics and identify promising points for theoretical exchange, making comparisons with Tinbergen’s four questions, which play a similar role in the evolutionary sciences. Finally, we propose cultural-evolutionary experiments for making empirical progress.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Eran Elhaik ◽  
◽  
Tatiana Tatarinova ◽  
Dmitri Chebotarev ◽  
Ignazio S. Piras ◽  
...  

2009 ◽  
Vol 32 (5) ◽  
pp. 451-452 ◽  
Author(s):  
A. Charles Catania

AbstractThis commentary argues that Evans & Levinson (E&L) should expand their two-track model to a three-track model in which biological and cultural evolution interact with the evolution of an individual's language repertories in ontogeny. It also comments on the relevance of the argument from the poverty of the stimulus and offers a caveat, based on analogous issues in biology, on the metaphor of language as a container, whether of meanings or of other content.


Author(s):  
Marieke Woensdregt ◽  
Kenny Smith

Pragmatics is the branch of linguistics that deals with language use in context. It looks at the meaning linguistic utterances can have beyond their literal meaning (implicature), and also at presupposition and turn taking in conversation. Thus, pragmatics lies on the interface between language and social cognition. From the point of view of both speaker and listener, doing pragmatics requires reasoning about the minds of others. For instance, a speaker has to think about what knowledge they share with the listener to choose what information to explicitly encode in their utterance and what to leave implicit. A listener has to make inferences about what the speaker meant based on the context, their knowledge about the speaker, and their knowledge of general conventions in language use. This ability to reason about the minds of others (usually referred to as “mindreading” or “theory of mind”) is a cognitive capacity that is uniquely developed in humans compared to other animals. What we know about how pragmatics (and the underlying ability to make inferences about the minds of others) has evolved. Biological evolution and cultural evolution are the two main processes that can lead to the development of a complex behavior over generations, and we can explore to what extent they account for what we know about pragmatics. In biological evolution, changes happen as a result of natural selection on genetically transmitted traits. In cultural evolution on the other hand, selection happens on skills that are transmitted through social learning. Many hypotheses have been put forward about the role that natural selection may have played in the evolution of social and communicative skills in humans (for example, as a result of changes in food sources, foraging strategy, or group size). The role of social learning and cumulative culture, however, has been often overlooked. This omission is particularly striking in the case of pragmatics, as language itself is a prime example of a culturally transmitted skill, and there is solid evidence that the pragmatic capacities that are so central to language use may themselves be partially shaped by social learning. In light of empirical findings from comparative, developmental, and experimental research, we can consider the potential contributions of both biological and cultural evolutionary mechanisms to the evolution of pragmatics. The dynamics of types of evolutionary processes can also be explored using experiments and computational models.


2018 ◽  
Author(s):  
Mashaal Sohail ◽  
Robert M. Maier ◽  
Andrea Ganna ◽  
Alex Bloemendal ◽  
Alicia R. Martin ◽  
...  

AbstractGenetic predictions of height differ among human populations and these differences are too large to be explained by genetic drift. This observation has been interpreted as evidence of polygenic adaptation. Differences across populations were detected using SNPs genome-wide significantly associated with height, and many studies also found that the signals grew stronger when large numbers of subsignificant SNPs were analyzed. This has led to excitement about the prospect of analyzing large fractions of the genome to detect subtle signals of selection and claims of polygenic adaptation for multiple traits. Polygenic adaptation studies of height have been based on SNP effect size measurements in the GIANT Consortium meta-analysis. Here we repeat the height analyses in the UK Biobank, a much more homogeneously designed study. Our results show that polygenic adaptation signals based on large numbers of SNPs below genome-wide significance are extremely sensitive to biases due to uncorrected population structure.


2019 ◽  
Author(s):  
Ke Wang ◽  
Iain Mathieson ◽  
Jared O’Connell ◽  
Stephan Schiffels

AbstractThe genetic diversity of humans, like many species, has been shaped by a complex pattern of population separations followed by isolation and subsequent admixture. This pattern, reaching at least as far back as the appearance of our species in the paleontological record, has left its traces in our genomes. Reconstructing a population’s history from these traces is a challenging problem. Here we present a novel approach based on the Multiple Sequentially Markovian Coalescent (MSMC) to analyse the population separation history. Our approach, called MSMC-IM, uses an improved implementation of the MSMC (MSMC2) to estimate coalescence rates within and across pairs of populations, and then fits a continuous Isolation-Migration model to these rates to obtain a time-dependent estimate of gene flow. We show, using simulations, that our method can identify complex demographic scenarios involving post-split admixture or archaic introgression. We apply MSMC-IM to whole genome sequences from 15 worldwide populations, tracking the process of human genetic diversification. We detect traces of extremely deep ancestry between some African populations, with around 1% of ancestry dating to divergences older than a million years ago.Author SummaryHuman demographic history is reflected in specific patterns of shared mutations between the genomes from different populations. Here we aim to unravel this pattern to infer population structure through time with a new approach, called MSMC-IM. Based on estimates of coalescence rates within and across populations, MSMC-IM fits a time-dependent migration model to the pairwise rate of coalescences. We implemented this approach as an extension to existing software (MSMC2), and tested it with simulations exhibiting different histories of admixture and gene flow. We then applied it to the genomes from 15 worldwide populations to reveal their pairwise separation history ranging from a few thousand up to several million years ago. Among other results, we find evidence for remarkably deep population structure in some African population pairs, suggesting that deep ancestry dating to one million years ago and older is still present in human populations in small amounts today.


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