Sunday, April 11, 2010

evolutionary linguistics

On page 176, Coyne claims that "biological speciation resembles the speciation of two closely related languages". On a different note, what is the role of the speech function in human evolution? Elaborate on the coevolution of linguistics and of the brain/skull. How does the progression of human evolution demonstrate morphological modifications conducive to the development of sophisticated language? what are the selective advantages and how has language shaped the evolution of society and culture? Compare to the evolution of other primates. Be sure to consult outside sources.


  1. Evolutionary adaptation, division, and genetic drift can be closely paralleled to the changes of language through time. In language, if a specific group has been isolated for long periods of time may "drift" away in new directs as each generation teaches their children the language slightly differently, eventually, the language is nearly unrecognizable by the original speakers. Similar things known as genetic drift, which usually occur most rapidly in small groups, is constant add up of mutations, and eventually will be nearly indistinguishable from its original species. For example, in language, take Mandarin Chinese for example, has many dialects, if a Northeastern Chinese person (people most often hired for news reporting) were to travel to southeastern china, the dialect would be so strong it would sound like a different language. In genetic drift, creatures that are separated, and usually most noticeable in a small group, such as "1900 hunting of the northern elephant seal off the Pacific coast had reduced its population to only 20 survivors" and as the population later increased, all of their descendants shared the same traits and were drastically different from other populations that weren't exposed.
    Looking at the Chinese language again, long ago, a common language that Mandarin and Cantonese "descended" from split into the two current languages. With the separated cultures between Beijing and Southern China, eventually the one language became two distinct languages, however, they still share many of their old traits. Speciation in animals occurs when different environments are presented to two populations, and eventually they speciate: such as between humans and apes about 11 million years ago. Where one was open savannas, the other was tropical forests, the two populations obviously split due to adaptation towards their environments.
    Finally, is the adaptation of creatures to fit their environments. In evolution, this occurs everywhere, whether in humans or in wolves. To understand this in terms of language, take this analogy. Say a government system bans the use of specific words, phrases, or knowledge about a subject. Eventually those words will be used less and less as the government enforces these rules. Then, eventually, the language will no longer have these words. The opposite of this would be the introduction of new words, and as popularity of it spread, it would eventually become part of the language.
    Evolutionary adaption, speciation, and drift can be easily represented by how language changes throughout time. Except in one, death and physical isolation is the controlling factor, and the other is communication and the rules created by society.

    Biology Book

  2. I like Tianyu's take on languages and society. I would like to focus more on the physical aspect of speech.
    There is clearly a selective advantage of communication among hunters. A good example is watching dogs bark at each other while playing. They are able to let other dogs know when they are excited, afraid, or angry by auditory means. K9's are model hunters. They often hunt in packs. Wolves are known to hunt moose. This is a kill that requires teamwork and communication. If a pack can kill one, the nutrition aids each member to survive and reproduce. The same advantage helped early humans.
    So how do we communicate? The first step is recognition. This takes place in the parietal lobe. This lobe interprets frequency of sound waves as they hit our ears. There is a selective advantage for our ear shape. Fish that lack this advantage, don't have protruding ears. Our enlarged brain has many connections that allow us to differentiate different frequencies and timbres. We can even tell the difference between hundreds of voices without seeing people's faces. Imagine early humans on the hunt. With this feature, they could be able to tell which group member was saying a particular message without looking.
    Next, humans would have to actually make the sound. All that's required for communication is one or two different sounds. This is why Morse Code works. However, the human voice can make an abundance of sounds. We're familiar with over 29 different sounds (A-Z, th, sh, ch). There are more as these vary by culture. The permutation of how many words a human can say is infinite. The mechanisms that allow us to create these sounds are the larynx, tongue, lips, and facial muscles. All of these features co-evolved due to the selective advantage of speech.
    These messages need to be loud enough to reach their intended subject. The mechanisms involved in this is the diaphragm, intercostal muscles, and every tube and air sack in between. These allow a dynamic range from a whisper to an opera singer. The selective advantage for this range is that humans can talk at appropriate volumes given a situation. If there's a predator is near, a loud yell can save the lives of the group. If the predator is 5 feet away, a whisper may be more appropriate. This is just one example of the use for volume control. There are many social advantages as well.
    Together, these features allow us to make many different sounds at a wide volume range. We can then interpret what is being said and who is saying it.

    Wolf diet
    the brain