Natural+Language+and+Natural+Selection+-+Pinker+&+Bloom


 * __Summary__**:

Some argue that human language evolution cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language evolved as a by-product of selection for other abilities or as a consequence of unknown laws of growth and form. Pinker and Bloom argue that it is appropriate and fits the requirements for Darwinian natural selection. Natural selection (in this article) states the only plausible explanation for the creation of near perfect organs is by adaptive complexity (where many interacting parts of a system arrange themselves to fulfill a specific function). For example, the complex design of the eye and the adaptation for visual imagery could only have occurred through a process of natural selection and those who did not need the function would not develop the eye. He then goes on to apply this to language, asking if language is a complex trait that has arisen through the process of natural selection? He then asks if it could also be used to explain the complex design of the cognitive mechanisms used in language? He concludes by discussing the difference between language evolution and language acquisition. The fact that early infants can distinguish different grammatical utterances and find the correct ones fairly quickly would indicate some cognitive mechanisms that are innate and much different to the evolution of how it got there. That this ability has been adapted to present complex functioning by natural selection and can continue to build upon it.


 * __Introduction__**:

1. Introduction -These and other facts suggest the ability to use a human language relates more to the study of human biology than of human culture:
 * All human societies have language, as far as we know they always did
 * Children are capable of learning language and have an innate ability to pick up on grammatical cues from other words they've learned
 * language is like echolocation in bats, not like inventing the wheel

Therefore it seems natural that language would be a product of natural selection

2. Role of Natural Selection in Evolutionary Theory
 * Gould frequently suggests that evolutionary theory is revolutionizing, adaptationism and gradualism are being questioned, if Darwinism is not an all-encompassing rule, it shouldn't be used to explain the origin of language

2.1 Nonselectionist Mechanisms of Evolutionary Change
 * Gould & Lewontin warn against "naive adaptationism" (see vocabulary section)
 * cite several nonadaptionist mechanisms that frequently aren't tested within evolutionary accounts: genetic drift, laws of growth & from, direct induction of form by environmental forces such as water currents or gravity, the effects of accidents of history, and "exaptation"

2.2 Limitations on Nonselectionist Explanations
 * Gould & Lewontin don't suggest so in their paper, but Gould has made suggestions such as that Darwinian natural selection be replace by "a better evolutionary theory (one based on 'exaptation')"
 * Main idea that undermines Gould and Lewontin's critique of adaptionism is that natural selection is the only scientific explanation of "adaptive complexity" (see vocabulary section)
 * i.e. it is impossible to make sense of structure of the eye without noting that it appears as if it was designed for the purpose of seeing, Darwin showed how such characteristics could come into being by the physical process of natural selection

2.3 Two Issues that are Independent of Selectionism
 * two other issues included in Gould's depiction of the scientific revolution in evolutionary theory which are largely independent of the role of selection in evolutionary change

2.3.1 Gradualism
 * Gould has suggested that "punctuated equilibrium" (see vocabulary section) has parallels with approaches to evolution that were discredited by the neo-Darwinian synthesis, such as "saltationism," "macromutations," or "hopeful monsters."

2.3.2 Exaptation
 * Exaptation is still gradual and driven by selection.
 * Theories of Gould, Lewontin, and Eldredge do not "invalidate gradual, natural selection."

3. Design In Language
 * Do the cognitive mechanisms underlying language show signs of design for some function in the way that the anatomical structures of the eye show signs of design for the purpose of vision?
 * What is the function (if any) of language?
 * What are the engineering demands on a system that must carry out such a function?
 * Are the mechanisms of language tailored to meet those demands?

3.1 An Argument for Design in Language
 * The human ability to aquire information (firsthand or from others) is advantagous to survival.
 * Language helps humans categorize and organize relationships between people and objects.
 * Grammar helps reduce ambiguity in intended meaning.
 * Some facts about substansive universals that help humans express ideas/knowledge.
 * Grammars are created around symbols.
 * Phrases can be combined to give more specific meaning.
 * Dog, my dog, those dogs, the dog that bit me.
 * Phrase structure can change the meaning of a sentence.
 * Order of words (linear order) can change meaning.
 * Man bites dog. Dog bites man.
 * Verb affixes help determine time categories.
 * John has arrived. John had arrived. John will have arrived.
 * Pronouns encode features.
 * He/she/it.

3.2 Is the Argument for Language Design a Just-So Story?
 * Its not entirety wrong to infer both special design and adaptationist origins on basis of function itself. Example being bats using sonar, not human noses holding spectacles on their faces.
 * Arguments that language is designed for communication of propositional structures is not accurate.
 * It has been suggested that convergent evolution, resemblance to man made artifacts, and a view of engineering efficiency are great places to find adaptation evidence. Although, there has yet to be a significant discovery of convergent evolution.

3.3 Language Design and Language Diversity?
 * Why do different languages have different grammar structures?
 * Grammars have different uses, but all grammars are "circumscribed," meaning that they are limited/restricted.
 * Chompsky believed that "...anything you find in one language can also be found in every other language..." just in different forms.
 * E.g. All languages have nouns that must be case marked.
 * Why is there more than one universal language?
 * Culturally different innovations.
 * Perhaps evolution has not yet found a way to evolve a "huge innate code."
 * Do we have a mechanism that helps us separate differences in language, or do we have a learning mechanism that led to the development of multiple languages?

3.4 Language Design and Arbitrariness
 * Piattelli-Palmirini believe that grammar lacks design and did not evolve by selection. But Pinker and Bloom go on to show that their position is invalid.

3.4.1 Inherent Tradeoffs
 * There is a conflict of interest between speakers and hearers.
 * Speakers want to minimize "articulatory effort.
 * Hearers want to minimize the effort of understanding, wanting clarity over brevity when listening.
 * There is also conflict between speakers and learners.
 * Subjacency helps us understand sentences like, "That's the guy that you heard the rumor about his wife leaving him."

3.4.2 Parity in Communications Protocols
 * "...the nature of language makes arbitrariness of grammar itself part of the adaptive solution of effective communication in principal."
 * Communication systems can have arbitrary protocol, as long as it is shared with others.

3.4.3 Arbitrariness and the Relation Between Language Evolution and Language
 * Acquisition
 * "If communicative function does not shape language in the individual, one might conclude, it probably did not shape language in the species."
 * Children can't learn any useful communicaton system or "natural language" because they must learn the language of their community.
 * Functionalist theories about the evolution of language can be true, but not their theories of language acquisition.
 * Children using words like "breaked" are understood, but eventually they learn rules that determine that that is not the proper way to communicate.
 * Summary: Grammatical devices may be important in language evolution, but not in language acquistion.

4. Arguments for Language Being a Spandrel
 * given that language satisfies the criteria of an adaptation, Pinker & Bloom examine the strength of the competing explanations by Gould, Chomsky, & Piatelli-Palmarini that language is a spandrel

4.1 The Mind as a Multipurpose Learning Device
 * Language learning is not considered programming. Parents provide their kids with sentences, not rules on sentences. Natural selection is suggested to be the programmer

4.2 Constraints on Possible Forms

5. The Process of Language Evolution
 * if universal grammar evolved by natural selection, it must not only be useful in a general sense, but there also must have been genetic variation amongst individuals in their competence.
 * there must have been a series of steps leading from no language to language as we now know it, each step produced by random mutation or recombination, and each useful to its possessor
 * there must be enough evolutionary time and genomic space separating our species from nonlinguistic primate ancestors
 * what we know from the biology of language & evolution makes each of these theories quite plausible

5.1 Genetic Variation According to Lieberman it is impossible for Chomsky's theory, universal grammar, to have evolved. The argument Lieberman makes is that syntax is acquired through learning and not innate.

5.2 Intermediate Steps
 * some doubt that an evolutionary sequence of increasingly complex and specialized universal grammars is possible, intermediate links have been suggested to be unviable communication systems. The arguments fall into three classes:

5.2.1 Nonshared Innovations Along with other ilk, Geschwind wondered in theory how the mutation of grammar would benefit, if some people's grammar evolved and others did not, leaving a gap in understanding.

5.2.2 Categorical Rules

5.2.3 Perturbations of Formal Grammars

5.3 Reproductive Advantages of Better Grammars

5.3.1 Effects of Small Selective Advantages

5.3.2 Grammatical Complexity and Technology

5.3.3 Grammatical Complexity and Social Interactions

5.3.3 Social Use of Language and Evolutionary Acceleration

5.4 Phyletic Continuity


 * __Conclusion__**:

6. Conclusion
 * Argue that language evolved by natural selection because:


 * 1) language shows signs of complex design for the communication of propositional structures
 * 2) the only explanation for the origin of organs with complex design is the process of natural selection
 * 3) none of the arguments by distinguished scientists amongst an array of fields that try to point to another source for language are compelling


 * New advancements in the field are always occurring that warrant further discussion and exploration of the origin of language, whether by natural selection or by some "catastrophic event."


 * __Vocabulary__**:


 * "adaptive complexity" - describes any system composed of many interacting parts where the details of the parts' structure and arrangement suggest design to fulfill some function
 * "exaptation" - new uses are made of parts that were originally adapted to some other function or of spandrels that had no function at all but were present for reasons of architecture, development, or history
 * Ergative: Relating to the subject of a transitive verb.
 * homeotic genes - genes that determine what parts of the body form what body parts (homeotic mutation, pg. 10)
 * Ideosyncratic: A mode of behavior peculiar to an individual.
 * "naive adaptationism" - a concept delineated by Stephen Jay Gould that refers to ad hoc and arbitrary evolutionary theories, such as noses being made for our glasses (inappropriate use of adaptive theorizing to explain traits that have emerged for other reasons)
 * Parity: The state of being equal.
 * Prosodic: Relating to the rhythmic aspect of language (wordnetweb).
 * "punctuated equilibrium" - theory which asserts that most evolutionary change doesn't occur continuously within a lineage, but is confined to bursts of change that are relatively brief on the geological time scale, generally corresponding to speciation events, followed by long periods of stasis.
 * saltation - sudden change from one generation to the next, this is large, or very large, in comparison with the usual variation of an organism, idea that new species arise as a result of large mutations
 * spandrels - tapering triangle spaces formed by the intersection of two rounded arches at right angles
 * Transitive Verb: A verb that is able to take a direct object. E.g. "Saw" in "He saw the donkey" (Dictionary.com).