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Human evolution: FoxP2 and speech

A friend warns, wisely in my view, that we be skeptical about vast claims made in the popular science press about human evolution.

One paper asserts that FOXP2 was probably involved in the evolution of speech and language, but another paper has cautioned about being too hasty in making this conclusion.

Well, after the “Ida” fossil took in Michael Bloomberg, I’d be cautious about anything evolutionary biologists say. So should Bloomberg, herafter.

For what it is worth, I also don’t believe that Flores man is really a separate human species, because I have seen proportionately formed women on the streets of Toronto who were not more than one metre tall. But it’s just the sort of squabble no one cares about, and figures like Michael Bloomberg do not get involved.

Here’s one assessment from the science literature: “The finding that FOXP2 is critical to speech and language does not by itself demonstrate the role of this gene in the origin of human speech, because the function of FOXP2 could have remained unchanged during human evolution while other speech-related genes changed.” (Jianzhi Zhang, David M. Webb and Ondrej Podlaha, “Accelerated Protein Evolution and Origins of Human-Specific Features: FOXP2 as an Example,” Genetics, Vol. 162:1825–1835 (December 2002).)

Here’s a suitably cautious paper by by Alec MacAndrew on the subject:

No-one should imagine that the development of language relied exclusively on a single mutation in FOXP2. They are many other changes that enable speech. Not least of these are profound anatomical changes that make the human supralarygeal pathway entirely different from any other mammal. The larynx has descended so that it provides a resonant column for speech (but, as an unfortunate side-effect, predisposes humans to choking on food). Also, the nasal cavity can be closed thus preventing vowels from being nasalised and thus increasing their comprehensibility. These changes cannot have happened over such a short period as 100,000 years. Furthermore the genetic basis for language will be found to involve many more genes that influence both cognitive and motor skills

Human mind needs human cognition and human cognition relies on human speech. We cannot envisage humanness without the ability to think abstractly, but abstract thought requires language.

One thing to keep in mind is that human language is also governed by the need to communicate things that no ape would need to communicate. So understanding language requires understanding mind.

Assume I have a car. Assume the mechanic at Canadian Tire is trying to explain to me what is wrong with my car.

I don’t know much about cars but I know that the car is not working. I accept his explanation and his promise to fix it. And my big question is, “What will this cost?”

That question assumes an exceedingly complex system of social transactions around that unpleasant subject, money.

I’d also like to know, “When will the car be ready?”

“Some time” won’t cut it around here. I need to know when to show up again on the transit, pay, and drive the car away. I have other things to do. So does the mechanic. He even has a time sheet. So do I.

But that assumes a “clock” view of time, again a complex human idea.

Also, that car is only drivable due to roads and bridges, which are again complex constructions, involving many social transactions that require language.

To me, the nonsense around ape “language” fails to distinguish the way in which human language conveys ideas about things that are meaningless in principle to animals.

If I were an ape, maybe I could solve all my problems by aiming a coconut at another ape’s head and then swinging rapidly through the trees.

Oh, you know what? Compared to paying $499.95 plus PST plus GST at Canadian Tire … maybe … find someone who really irritates me and … WHACK!!!

Naw. He can’t help being an ape and I can’t help being human. Just how life is. Better keep the coconut for Christmas baking.

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4 Responses to Human evolution: FoxP2 and speech

  1. The FoxP2 gene is by no means inconsistant with common descent. However, like the HAR1F, it is a highly stable gene that is decidedly different in humans than in the other mammals. Two facts need to be rectified when the HAR1F is considered.

    1 – This gene’s high stability would indicate that any single mutation in the FoxP2 is net deleterious.

    2 – Behe’s “The Edge of Evolution” effectively rules out two mutations if both, on their own, are deleterious.

    3 – The modified FoxP2 causes changes to the structure of over 100 protiens. As 99.*% of protein modification is either neutral or deleterious, pulling off an edit that affects so many proteins, without producing a genetic catastrophy is highly unlikely.

    The FoxP2 presents a serous challenge to the neo-Darwinian hypothesis.

    Its nice to see a thread on data, rather than just philosophy. (Not to undervalue the philosophy, only to value the evidenciary case.)

  2. Paleoanthropologists have been trying to work out what H. floresiensis is ever since the material was first discovered. Glad you could solve the problem without even laying eyes on the skeleton, much less performing any kind of analysis of the material:

    For what it is worth, I also don’t believe that Flores man is really a separate human species, because I have seen proportionately formed women on the streets of Toronto who were not more than one metre tall.

    One problem with this statement is that Homo floresiensis does not have the same body proportions as anatomically modern H. sapiens. Then, of course, there are all those traits linking H. floresiensis to H. erectus and other traits linking H. floresiensis to the australopithecines.

  3. grannyape92, living as I do in a multicultural city, I am familiar with specimens of homo sapiens who have strikingly diverse body proportions – though they usually resemble their own relatives, for whatever reason.

    What struck me about homo Flo was that they lived pretty much the same way all humans of their generations lived.

    Yes, doubt is a dangerous thing – but misplaced faith is much more so.

  4. Oh, now you are changing your story. Before it was

    …I have seen proportionately formed women on the streets of Toronto who were not more than one metre tall

    now its

    …I am familiar with specimens of homo sapiens who have strikingly diverse body proportions…

    certainly achondroplastic dwarfs have limb length proportions unlike others, they are also unlike H. floresiensis. You also failed to address the point that H. floresiensis shares quite a few traits in common with H. erectus and the earlier australopithecines (the aforementioned limb length proportions being one). At this point, there is quite a bit of doubt as to what H. floresiensis actually is and the taxonomic position and phylogenetic status of H. floresiensis will be the subject of a lot of future research. So your last point is kind of meaningless considering the unsettled status of H. floresiensis.

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