Högskolan Dalarnas logga och länk till högskolans webbplats

The main part of this thesis treats measurements in the HELIOS experiment of the production of e-mu and mu+mu-pairs in 450 GeV/c p-Be collisions. The mumu measurement covers the kinematical covers the kinematical range of 2Mmu < M < 1.5 GeV, 0.03 < xF < 0.25, and 0 < pT < 2 GeV. Production of the vector mesons rho, omega , and phi is observed. The branching ratio omega to mu+mu- is for the first time experimentally measured. The continuum at masses below the mu mass is studied, and compared with the contributions from known sources, normalized to the vector meson peaks in the mu+mu- mass spectrum, and to measurements in this experiment of the mu cross section. The res ult is compared with that of other experiments, discussed in terms of different background estimates used. A significant signal of unlike-sign e-mu-pairs is observed, forming a continuum peaking at a mass below 500 MeV. Correlations between e-mu and neutrino production are studied. The shape of the e-mu mass and missng-energy spectra indicate significant non-charm contributions. A search for lepton-number-violating decays is made, resulting in upper limits on a number of branching ratios. Also discussed here is the author's work in the DELPHI experiment, contributions that are related to analysis of heavy quark production. Keywords: muon. pair, dimuon, dilepton, lepton, low mass, continuum, eta, rho, omega, branching ratio, emu, e-mu, mue, mu-e, muon-electron, electron-muon, electron, charm, neutrino, missing energy

All you need is love… or what?

Language is essentially always present in groups of modern humans. Even in the exceptional groups that for some reason are formed without language, language will invariably emerge in short order. Examples of language emergence in recent times include deaf communities in e.g. Nicaragua and Israel. Such newly-formed languages converge within a few generations towards the same general form and features as mainstream human languages.

Language is essentially never present in groups of non-human primates. Even in the exceptional groups that are heavily exposed to language and explicitly trained in language use, progress in language acquisition is invariably modest at best. Language never emerges spontaneously in non-human groups.

What’s special with humans? It is sometimes argued that “all you need is merge” (e.g. Berwick 2007), that a small genetic change provided a language-ready brain and the rest is history. This saltational view of language evolution is wrong for many reasons (e.g. Tallerman 2014), but I would add here another one.

A language-ready brain is not an all-or-nothing affair, nor is it sufficient for language emergence. The results of language training in apes are modest, but not nil. Apes do learn to connect symbols with referents and use them communicatively. One may quibble about whether to call this “language”, and it is far from full human language, notably lacking in syntax. But it does show the presence of some language-relevant abilities in apes, and it is a functional communication tool at some protolinguistic level.

But if ape brains are protolanguage-ready, why doesn’t protolanguage emerge in the wild among apes, as it does among humans? Clearly, some extra-linguistic key factor is lacking. A language-ready brain is not all you need for language emergence. In a group of hypothetical creatures with a human language faculty (narrow sense) but otherwise ape-like in psychology and behavior, language would not emerge.

Human prosociality and shared intentionality are likely key ingredients in language emergence (e.g. Tomasello 2010), but are not the whole story. In this talk, I will explore the minimal extra-linguistic requirements for protolanguage emergence to get off the ground in protohumans.

References:

Berwick, R C (2011) All you Need is Merge: Biology, Computation, and Language from the Bottom-up.  In di Sciullo & Boeckx The Biolinguistic Enterprise OUP.

Tallerman M. (2014) No syntax saltation in language evolution. Language Sciences 46, 207-219.

Tomasello, M (2010) Origins of human communication. MIT Press.

Noam Chomsky (2005) proposed that a ‘third factor’, consisting of general principles and natural laws, may explain core properties of language in a principled manner, minimizing the need for either genetic endowment or experience. But the focus on third-factor patterns in much recent bio-linguistic work is misguided for several reasons: First, ‘the’ third factor is a vague and disparate collection of unrelated components, useless as an analytical tool. Second, the vagueness of the third factor, together with the desire for principled explanations, too often leads to sweeping claims, such as syntax “coming for free, directly from physics”, that are unwarranted without a case-by-case causal analysis. Third, attention is diverted away from a proper causal analysis of language as a biological feature. The point with biolinguistics is to acknowledge the language faculty as a biological feature. The best way forward towards an understanding of language is to take the biology connection seriously, instead of dabbling with physics.

1. Introduction

A major component in the evolution of language is the evolution of the human language capacity, whatever biological endowments humans have that make us language-ready. But the language capacity is not well understood and is difficult to study directly. Clues may come from biases displayed by humans in language acquisition and language change. Even weak underlying biases can lead to strong patterns in the resulting languages (Smith, 2011). Biases can be studied at the individual level in learning experiments (e.g. Culbertson, 2012, Tamariz et al., of natural languages (e.g. Dediu & Ladd, 2007). Biases can be seen either in the synchronic patterns of language features today, or in the diachronic patterns of transition probabilities between features as languages culturally evolve (e.g. Dunn et al, 2011).

Patterns that reveal biases may be found in any aspect of language, e.g. syntax, morphology, phonology, or lexicon, and may be subtle enough to be discernible only in large samples of languages. This work is an exploratory study across the widest possible set of languages, combining typological, phonological, lexical and phylogenetic data on a significant fraction of the languages of the world, with the goal of mapping any biases that may be present. Both synchronic and diachronic patterns are studied, with the emphasis on the latter.

2. Data set

The following data sources are used:

•Phylogeny and geography: Ethnologue (Simons & Fennig 2017); ~7,500 languages.

• Phonological inventories: PHOIBLE (Moran & McCloy & Wright 2014); ~1,800 languages.

• Typology: WALS (Dryer & Haspelmath 2013); ~2,500 languages.

• Lexicon (Swadesh lists): Rosetta Project Digital Language Archive (2009); ~1,300 languages.

All four types of data are available for ~300 languages. At least three types are available for ~1,600 languages from 132 different stocks. In order to keep the data set as homogeneous as possible, each type of data has been imported from a single source only. Languages are identified between data sources by their ISO codes. 3. Methods

The language phylogeny from Ethnologue is taken as given in the analysis. For the synchronic analysis, the phylogeny is taken into account in the character statistics by down-weighting multiple “hits” in the same family, in order to control for phylogenetic bias and lineage-specific patterns. Geographic data is also available to control for areal effects. Cross-correlations between different types of characters are analysed for possible patterns. For the diachronic analysis, the phylogeny together with modern-day character data are used to infer both ancestral character states up the language tree for phonological and typological characters, and transitional probabilities between states (including the probability of characters appearing and disappearing), in a bootstrapping process. 4. Some preliminary results

Well-known typological patterns are reproduced. But correlations between features are observed that go beyond those normally discussed in typology, or those observed by Dunn et al (2011). Interestingly, there are also some modest cross-correlations between grammatical features and phonemes. For example, the presence of aspirated consonants and nasal vowels correlates with certain word- order features, even after controlling for phylogeny. In the diachronic analysis, there are hints of patterns beyond the obvious one that transition probabilities into common features are larger, but much work remains to be done in the interpretation of these patterns.

The precise timing of the emergence of language in human prehistory cannot be resolved. But the available evidence is sufficient to constrain it to some degree. This is a review and synthesis of the available evidence, leading to the conclusion that the time when speech became important for our ancestors can be constrained to be not less than 500,000 years ago, thus excluding several popular theories involving a late transition to speech.

The precise timing of the emergence of language in human prehistory cannot be resolved. But the available evidence is sufficient to constrain it to some degree. This is a review and synthesis of the available evidence, leading to the conclusion that the time when speech in some form became important for our ancestors can be constrained to be not less than 400,000 years ago, thus excluding several popular theories involving a late transition to speech.

It is commonly assumed in evolutionary linguistics that language evolved for communication.But much recent work in biolinguistics, e.g. Chomsky (2010), proposes instead that languageevolved for purely internal use, as a cognitive tool, with no externalization until at a later stagein language evolution.How well supported is really our general assumption of communicative language origins? Doesit make sense to have instead an early stage with internal language only? I will review the argumentsinvoked in favor of the incommunicado hypothesis, and critically evaluate their strength.

Why do humans have language at all and how did we become language users? These are central questions in language evolution, but no general consensus exists on the answers, nor even on what methods to use to find answers. This is a complex topic that requires input from many disciplines, including, but not limited to, linguistics, evolutionary biology, palaeoanthropology, neurobiology, archaeology, cognitive science, and primatology. Nobody is an expert in all these areas, and experts in one area sometimes overlook needed input from other areas. Consensus does not even exist among linguists on what language is—opinions range from the physical speech acts themselves to language as an abstract social communication system to language as computational machinery in the individual and to language as an innate species-defining, genetically encoded capacity of humans. These different views of language imply very different evolutionary explanations. At the same time, all of these perspectives have some validity; the speech acts do occur, language use does take place in a social context, the individual language user does somehow produce and parse sentences, and human babies are born with a predisposition for language learning that ape babies lack. The disagreements are mainly a matter of emphasis, namely which aspects are regarded as of primary interest, requiring explanation. The preeminent linguist of the early 20th century, Ferdinand de Saussure, focused on the first two perspectives with his distinction between parole (speech acts) and langue (the social system). The preeminent linguist of the late 20th century, Noam Chomsky, focuses instead on the latter two, especially the computational machinery, and he regards the first two as not worthy of a linguist’s attention. But neither focus is adequate on its own; a viable theory of language evolution must be able to explain all aspects of language, notably both the evolution of the language capacity that resides in each human brain and the evolution of the human social context in which language is used. No generally accepted theory exists today. Instead of a single accepted theory, the field of language evolution is awash with a multitude of different models, scenarios, and hypotheses about how things might have happened. To make matters worse, there is something of a paradigm split in the study of language origins. The split is largely along the line between Saussure and Chomsky mentioned above. To put it simply, those researchers who use the label “biolinguistics” try to explain the origin of Chomsky’s computational machinery (see Biolinguistics) whereas most work on language evolution is concerned with explaining the origins of Saussure’s langue, language as a social system; the latter is here called “mainstream evolutionary linguistics.” Language evolution is not, however, about the origin of individual languages (English, Chinese, etc.). Sometimes “language evolution” is used to refer to diachronic language change in recent times, as studied by historical linguists, and an evolutionary perspective can indeed be fruitful in this area. But this article does not cover that kind of language evolution, except peripherally in Cultural Evolution.

Chomsky (e.g. 2010) and others regard unlimited Merge as the defining feature of language, that cannot evolve gradually. The neural implementation of Merge is not well understood (Rizzi 2012, Zaccarella et al 2017), but must involve something functionally equivalent to pointers in working memory. Every Merge requires two pointers, and full syntactic trees may require dozens. Other syntactic paradigms also need pointers.

Humans do hierarchies in general better than chimpanzees. Any hierarchical thinking requires nested pointers in working memory, but they are neurologically expensive and degrade with depth (Crawford et al. 2016). Humans have larger working-memory capacity than chimpanzees, which has been proposed as key to human cognitive evolution (Read 2008, Coolidge & Wynn, 2005). Gradual evolutionary growth of pointer capacity will allow gradually increasing syntactic complexity, without saltations in the underlying computational machinery. Both depth degradation and pointer capacity naturally limit Merge even in modern humans, consistent with corpus data (e.g. Karlsson 2010).

Chomsky, Noam. (2010). Some simple evo devo theses: how true might they be for language? In Richard K Larson, Viviane Déprez, & Hiroko Yamakido (Eds.), The Evolution of Human Language. Biolinguistic Perspectives. Cambridge: Cambridge University Press.

Coolidge, Frederick L & Wynn, Thomas (2005) Working memory, its executive functions, and the emergence of modern thinking. Cambridge Archaeological Journal 15:5-26.

Crawford, Eric & Gingerich, Matthew & Eliasmith, Chris (2016) Biologically plausible, human-scale knowledge representation. Cognitive Science 40:782-821.

Karlsson, Fred (2010) Syntactic recursion and iteration. In Harry van der Hulst, ed., Recursion and Human Language. Berlin/New York: Mouton de Gruyter,

Read, Dwight W (2008) Working memory: A cognitive limit to non-human primate recursive thinking prior to hominid evolution. Evolutionary Psychology 6:676-714.

Rizzi, Luigi (2012) Core linguistic computations: How are they expressed in the mind/brain? Journal of Neurolinguistics 25:489-499.

Zaccarella et al (2017) Building by syntax: the neural basis of minimal linguistic structures. Cerebral Cortex 27:411-421.

When we talk about protolanguage, it is typically in the singular. The name of this conference series is Exhibit A here, but also e.g. the authoritative Oxford Handbook of Language Evolution talks about “the protolanguage” (Tallerman, 2012, my emphasis). This leads us to imagine a single protolanguage being spoken (or signed or mimed or whatever) at some point in prehistory. At most we imagine multiple successive stages of more and more advanced protolanguages (e.g. Jackendoff & Wittenberg, 2014, Author, submitted a). 

But rarely has the likely diversity of protolanguages been considered. A literature search for “protolanguages” in the plural mainly returns results referring to the proto-forms ancestral to modern language families (proto-Indoeuropean, etc.); see Robbeets et al. (2020) for an example. There are rare exceptions referring to plural protolanguages in the sense used at this conference (e,g, Donald, 1999, Dowman, 2008) but they still do not have diversity in focus.

Is there any reason to believe that linguistic diversity in the world was any less in prehistory than it is today? The answer to that question depends on whether the forces driving linguistic diversification were operative already at the protolinguistic stage. If two groups speaking the same language get separated, their dialects will gradually drift apart over time until mutual intelligibility is lost, the linguistic equivalent of genetic drift in biology; this must have been operative for as long as we had conventionalized language at all. Differential language contact can also cause language change, with different subgroups accumulating different loanwords etc. In this way, diversity begets more diversity, and this would have been operative as soon as some diversity was present. Finally, if language is used as a marker of group identity, a group may intentionally steer their way of speaking away from the neighbors’. This requires a level of meta-linguistic awareness that need not have been present from the beginning. 

But even without the latter force, linguistic drift and language contact would have been quite sufficient to drive diversity among protolanguages. And even in the absence of synchronic diversity, linguistic drift would create diachronic diversity: over a millennium or so, a modern language changes beyond intelligibility, and across 10,000 years it changes beyond recognition even at the family level. Even if we assume for the sake of the argument that protolanguage was a single lineage, every 1,000 years what is spoken deserves to be called a new language.

A single lineage is, however, extremely unlikely. From the dawn of language, people have spread out over multiple continents, far out of touch with each other. Protolanguages must have diverged. But populations were sparse, estimates for world population at relevant times are typically below one million, sometimes well below (e.g. Huff et al. 2010), living in small tribes. From such numbers, a rough order-of-magnitude estimate of the total number of protolanguages ever spoken can be calculated (Author, submitted b). With any reasonable assumptions, the number is huge, much larger than current linguistic diversity.

Vad heter du? Den frågan har du fått många gånger.

Men varför heter du? Den frågan har du kanske inte tänkt på så ofta. Hur kommer det sig att du över huvud taget har ett namn, och varför ser det ut som det gör? Det vill Sverker Johansson berätta om i denna underhållande och tanke­väckande bok. Med blick för såväl de stora utvecklings­linjerna som för de kuriösa exemplen rör han sig mellan alla tider och platser för att fånga in namntraditionernas mångfald.

Beroende på var vi hamnar i tid och rum kan ett för­namn bestämmas utifrån veckodag, förfäder, vilka onda andar som ska luras eller vad modern ser när barnet föds. Förutom förnamn kan vi ha efternamn – men också föräld­ranamn, gårdsnamn, bynamn, barnnamn, kastnamn, mel­lannamn, generationsnamn eller tillnamn baserade på allt från lyten via yrken till tv-program. Visste du till exempel att Caligula betyder barnstövlar, att John är det vanligaste förnamnet på Wikipedia, att delfiner har namnmelodier och att Mao Zedongs mellannamn Ze kommer från en dikt som hans släkt i fjorton generationer hämtade namn ur?

Mycket pekar på att vi bär namn inte så mycket för att kunna tilltalas som för att kunna omtalas…

Neanderthal language abilities cannot be directly observed, but indirect evidence is available in their anatomy, archeology, and DNA. Neanderthal anatomy shows possible speech adaptations, and their archeology contains enough indicators of behavioral modernity, including symbols and ornaments, to conclude that their minds could handle symbolic communication. Neanderthal DNA, finally, indicates both that they possessed some of the language-relevant genes found in modern humans and that they could and did have children with modern humans. From the consilience of evidence from anatomy, archeology, and DNA, one can conclude that some language abilities, if not necessarily full modern syntactic language, were present in Neanderthals.

Midwives and the birth of language

Sverker Johansson

Dalarna University

Sweden

Language is a paradox in signal evolution theory. Cheap signals can evolve only between beings who trust each other, or who have totally aligned interests. But totally aligned interests is a utopia, and our knuckle-walking relatives generally do not trust each other? How and when did human trust evolve? This will set a baseline for language evolution – except that trust does not fossilize any more than language does.

What fossil and archeological proxies for trust can be found? Trust is a social matter, but even proxies for sociality are not trivial to identify (Johansson 2014). Probably the best proxy for human trust was identified by Hrdy (2011), in proposing cooperative breeding as a key innovation in human evolution. Ape mothers are paranoid about their babies, for good reason, and will not let anybody assist them. But in all human cultures, family and friends will routinely cooperate and help a mother with her children, and experienced women will serve as midwives in labor. This makes a huge difference for human fertility, our reproductive rate “in the wild” is roughly double that of other apes. This provides the Darwinian payoff needed to overcome the threshold of mutual mistrust, and paves the way for cheap linguistic communication.

Midwife assistance in labor may facilitate language evolution also in another way, as it eases obstetric constraints on brain size.

I will review here the fossil and archeological evidence indicating the presence among our ancestors of the modern human pattern of cooperative breeding and labor assistance. The conclusion is that the first midwife most likely was a Homo erectus… and maybe some millennia later a young erectus first cried “mama”, when left in the care of an auntie.

Hrdy, Sarah Blaffer (2011) Mothers and Others. The Evolutionary Origins of Mutual Understanding. Cambridge, MA.: Harvard University Press.

Johansson, Sverker (2014) How can a social theory of language evolution be grounded in evidence? In Lewis, Jerome, Daniel Dor & Chris Knight (eds.) Social Origins of Language. Oxford: Oxford University Press.

Ackermann et al. treat both genetic and paleoanthropological data too superficially to support their conclusions. The case of FOXP2 and Neanderthals is a prime example, which I will comment on in some detail; the issues are much more complex than they appear in Ackermann et al.

Sverker Johansson has written an unusual book on language origins, with its emphasis on empirical evidence rather than theory-building. This is a book for the student or researcher who prefers solid data and well-supported conclusions, over speculative scenarios. Much that has been written on the origins of language is characterized by hypothesizing largely unconstrained by evidence. But empirical data do exist, and the purpose of this book is to integrate and review the available evidence from all relevant disciplines, not only linguistics but also, e.g., neurology, primatology, paleoanthropology, and evolutionary biology. The evidence is then used to constrain the multitude of scenarios for language origins, demonstrating that many popular hypotheses are untenable. Among the issues covered: (1) Human evolutionary history, (2) Anatomical prerequisites for language, (3) Animal communication and ape "language", (4) Mind and language, (5) The role of gesture, (6) Innateness, (7) Selective advantage of language, (8) Proto-language.

Chomsky (e.g. 2010) and others regard unlimited Merge as the defining feature of language, that cannot evolve gradually. The neural implementation of Merge is not well understood (Rizzi 2012, Zaccarella et al 2017), but must involve something functionally equivalent to pointers in working memory. Every Merge requires two pointers, and full syntactic trees may require dozens. Other syntactic paradigms also need pointers.

Humans do hierarchies in general better than chimpanzees. Any hierarchical thinking requires nested pointers in working memory, but they are neurologically expensive and degrade with depth (Crawford et al. 2016). Humans have larger working-memory capacity than chimpanzees, which has been proposed as key to human cognitive evolution (Read 2008, Coolidge & Wynn, 2005). Gradual evolutionary growth of pointer capacity will allow gradually increasing syntactic complexity, without saltations in the underlying computational machinery. Both depth degradation and pointer capacity naturally limit Merge even in modern humans, consistent with corpus data (e.g. Karlsson 2010).

Identifying possible stages of protolanguage critically depends on the underlying nature of language. Theories of language differ in evolvability, and in whether they permit protolanguage stages. In this presentation, I will study the protolanguage potential and evolva­bility of Construction Grammar. Postulating that CG is a biologically real description of language, its evolvability through a sequence of intermediate protolanguages is investigated.

Hur blev människan med språk? Var, när och varför bör­jade vi tala? Det är en av historiens stora gåtor. Än är vi långt ifrån en lösning, men med hjälp av så olika vetenska­per som arkeologi, neurologi, lingvistik och biologi kan vi numera dra några slutsatser, avfärda vissa äldre hypoteser och uppställa nya frågor.

Med entusiasm och sakkunskap lotsar Sverker Johansson läsaren genom en djungel av ledtrådar och teorier. Sök­andet efter språkets ursprung börjar många miljoner år tillbaka i tiden, då dagens apor och människor gick skilda evolutionära vägar. Det slutar vid den punkt dit det går att härleda förlagorna till de språk som talas i dag, det vill säga för omkring fem tusen år sedan. Däremellan får vi stifta bekantskap med Homo erectus och neandertalare, med Darwin och Chomsky, med delfiner och näktergalar, med syntax och interjektioner.

Men hela tiden tycks spåren leda tillbaka den omväl­vande period för omkring en och en halv miljon år sedan, då våra förfäder i Afrika ställdes inför nya situationer och alltmer började skilja sig från övriga djur och där språket av allt att döma tycks ha spelat en nyckelroll.