Tuesday, January 24, 2006

Reclassifying Chimps and Enhancing Humans

Two recent articles caught my attention and it is pure coincidence that one is about new evidence for reclassifying chimps in the evolutionary tree and the other is about re-engineering humans.

Dr. Soojin V. Yi* and her colleagues 'performed a large-scale analysis of lineage-specific
rates of single-nucleotide substitutions among hominoids.' They 'found that humans indeed exhibit a significant slowdown of molecular evolution compared to chimpanzees and other hominoids.'
Nucleotides are structural elements of DNA. During evolution, a nucleotide in a DNA sequence can be replaced or substituted. The substitution may result, depending on internal and external factors related to the organism, in phenotypical and organismic differences thus contributing to the temporal and cladistic divergences of Species. Nucleotide substitution is an important component of what is called a Generation Time of a species, or the history of the DNA of this species, or the molecular clock of the species. Generation Time for a species is the average rate of Nucleotide substitution per Loci (localisation on the DNA sequence) and per year. The less there are Nucleotides substitutions, the more the Generation Time is slow.

According to this approach:
Nucleotides substitutions differences between Hominoids and Chimps indicate that Hominoids diverged recently.
Chimps still have the slowest Generation Time among non Hominoids.
Chimps' Generation Time is, among non Hominoids, the closest to that of Hominoids.

Because of this, researchers conclude that Chimps and Hominoids didn't diverge very much and propose reclasifying Chimps among Hominoids.

That's an interesting proposal based entirely on the study of DNA sequences and changes in DNA sequences across species and across time. However small the difference can be between us humans and our closest cousins, the Chimpanzes, one must admit that behavioural differences are huge. We are today studying the Chimpanzes genome and kindly proposing to make them even closer to us, Chimps cannot do this. How this came to happen with such a small difference between them and us ?
Some people might say Language, others might say Technology and I think the second answer contains both since language was the first technology among humans. Language is Technology at its source, the emergence of fine (handy) motor skills, as their practice was made possible in Bipeds, paved the way for a better performance by the speech muscles. There are certainly other concomittant factors that contributed to this first technology, however we have to remember that language is technology and action before it is cognition. Language came first and higher cognition after.

Since it mastered this first technology, our species built on it to extend the power and the number of its tools. Technology, and its cumulative progress, became part of our phenotype and an integral part of our phenotypic expression. It acts on the phenotype the same way nucleotide substitution acts on it. This is exactly what separates us from Chimps and makes the behavioural divergence great despite the small nucleotide substitution.

Now that we are ready to aknowledge our kins as part of our larger Hominoids group, it seems to me that we are ironically using technology to 'enhance' or modify our human phenotype, and the new modifications we are seeking for our phenotype are not just external, they are internal to what defines us as humans; Memory, Intelligence, Mood and so on...

Under the title ' Science will soon give some of us the tools to make ourselves cleverer and stronger. What will it mean for our humanity? ' Madeleine Bunting** wrote a fictional piece based on this new trend in technology that may be called Human Enhancement Technology. Although all technologies are basically enhancement in a certain form or another, the race for making ourselves stronger, brighter, and less depressed, will be routine 25 years from now. It will be based on a two way approach: Genetic manipulations and cognitive enhancement, tools which are used already now in a restrictive manner for people who need them (challenged andor mentally ill people, and might become routine for anybody trying to cope with the ever increasing challenges of life. Bunting's piece, although fictional, is totally convincing because it relies on two premices: our hunger for new technology serving personal purposes like perfection, the ever increasing personal and professional challenges of our societies, and the fact that the technology she describes is already in motion.
''My daughter is 10. Fast forward 25 years, and she is having her first child - early by the standards of all her friends, but she's keen on "natural". Of course, she did pre- implementation genetic diagnosis, and she and her husband (yes, very old fashioned, they married) had some agonising days deciding on whether to modify a genetic predisposition to depression and whether to splice in a gene for enhanced intelligence. In the end, they felt they had no option but to give their baby the best possible start in life.
Five years later, my little grand-daughter is starting school. Again her parents have talked over the pros and cons of cognitive enhancement. A pharmcogenetic package is now routinely offered on the NHS after the government decided that, given international competition in the global knowledge economy, there was no option but to ensure the nation's schoolchildren had better powers of memory and concentration. I had my doubts, but I have to admit that my little granddaughter is proving a wonderfully clever creature - a constant source of amazement to me.
My doubts were in part assuaged by the fact that I had already started stronger doses of the same cognitive enhancement drugs. They've helped hugely with my forgetfulness (I'm just hitting my 70s). They are part of a cocktail of drugs I'm now taking to postpone many of the effects of ageing. I dithered a bit but in the end there was no option. I'm doing the childcare for all my five grandchildren and I need to be strong and fit for them. My age expectancy is now 110, so the plan is that I can help out a bit with the great grandchildren too.
What we've been unhappy about is that my daughter has been very tired trying to hold down her job and be a mum, and she's come under a lot of pressure from her boss to get help. What they mean is that she should go on to Provigil. They point out that if she was taking it, she could miss several nights of sleep without any problem. Her colleagues call her a bio-Luddite for refusing. She's already the only one not to have taken her company's early diagnosis - she said she didn't want to know whether she was going to get Alzheimer's disease in 30 years' time.

A delicious piece of writing. None of this will be fiction in a couple of years and I don't think we will wait 25 years from now to make this technology routine. Surely, Chimps can still hope catching us one day but we have been, since the dawn of humanity, running in the other direction, a direction opposite to Nature. It is la fuite en avant, as they say in French. As we are starting a new era, the Human Enhancement Technology with its new tools focused on cognitive enhancement will become the technology that will modify the very notion of Humanity itself. As we race towards 'perfection' and pull ourselves from the natural world to a world created by our own making, how would we still define ourselves and, most importantly, how would we adapt our moral values to this new reality ?

*Variable molecular clocks in hominoids (Proceedings of the national Academy of Science, January 31, 2006, vol. 103, no. 5, p.1370–1375)
**There is no stop button in the race for human re-engineering, Madeleine Bunting, The Guardian, Monday January 30, 2006.


tc said...

I find your identification of language as a technology to be unconvincing. The evolution of Language involved a series of heritable adaptations that in turn enabled rapid evolution/co-evolution of cognition. In humans the capacity for language is innate (heritable) whereas technology is a cultural product that is transmitted socially, not genetically. Higher Apes have the capacity for symbolic communication and of course cognition but both may not have evolved as dramatically as in humans. I also would suggest that the idea of chimps catching up with us is problematic as chimps have not evolved to catch up with humans and as such their evolutionary trajectory (if it were allowed to continue) may lead to a different result (or extinction, whichever comes first). Finally one thing to appreciate is that since evolution and its mechanisms (including natural selection) are always at work, even man induced enhancements may be subject to these forces. Anyone familiar with domestic dog, cat or pigeon breeds knows that enhancement of one trait may come at an expense of deficiency of others. It is not always a quid pro quo but there is indeed a law of unintended consequences at work. One must be careful what one wishes for.

Sonia Mansour-Robaey said...

My identification of language as a technology may be unconvincing. However I would like to size upon your comment to explicit more my point. I don't think that you can draw a clear line between biology and culture: both interact and participate to the building of our phenotype and there is strong evidence in modern developmental neurobiology for this. Work by Michael Meaney and colleagues highlight the importance, and in some way, the prevalence over genetic heredity, of 'culturally' transmitted traits in the reaction to stress in rats.
Having made this point I now return to the argument of language as a technology. Certainly language is a biological trait which evolved over a long time but then Chimps have the brain areas for language that we have. New and ongoing evidence point to the factors that may have made the difference between us and apes:
The liberation of the hands by switching from trees to open space and from quadripeds to bipeds. Hands use contributed to the emergence of fine motor skills, so instead of saying Hoo, Hoo, Hoo, we started shouting There ! A Buffalo ! Or whatever...The transition might not have been so sharp but it is this kind of transition that enabled us to speak languages. William Calvin defends this kind of hypothesis and there is scientific evidence for it.
In light of all this, language is a tool, it is the creation of the fine motor skills of our lips, tongue, mouth... in the same way the first stone tools, a creation of the fine motor skills of our hands served us well.
I hope I am a little bit more convincing now.

tc said...

First I want to commend you on this web site which deserves a wide readership for the quality of its posts and their relevance to the broad theme of science and society. You clearly put lots of loving effort into your posts and it shows.

It appears to me that the jist of your argument here is that humans are distinguished from their closest primate relatives (Chimps) by being technology heavy with technology becoming part of the human phenotype, first manifesting as language and later evolving to a capacity to manipulate once own genome and implictly, direct our own evolution. I still find your definition of langauge as a technology to be highly problematic and unlikely to convince, even after you clarifications. Better define it as a technology enabling biological trait.I would be wary of conflating the motor execution of language with technology, the latter being a social rather than a biological (heritable) phenomenon. To me the back to nature twist at the end of your piece can be reformulated as a question of whether one could ever escape the forces of evolution (nature) at work. I think not and I am always impressed at how events seemingly trivial at the time can have profound implications in the long term. Hence my comments about tinkering with dog breeds to obtain improved performance/intelligence or even looks and finding all sorts of unintended negative consequences croping up down the line scuh as disease and morbidity.

Sonia Mansour-Robaey said...


You are right about unintended consequences. The difficulty is that we may come to realize some unintended and negative consequences on dog breeds for example and on the environment but we may not be able to realize this when it comes to us because we are at both ends of the cause-consequence chain. As for my argument on language as a motor skill and a technology, I understand that you make a difference between, lets say, a car which is entirely a cultural creation and artifact, and language which is a natural biological capacity (a biological category according to R. Millikan) when it is difficult to view a car as a bilogical category. I have a problem with this kind of clear-cut differences as I have with other ontological differences made up by philosophers. I am not an essentialist, I am interested by how things work, but if I have to see those things from an essentialist point of view, I would say that all cultural and technological items, even religion, are biologiocal categories because they are the products of us humans who are biological categories in the first place.
This is not to say that I am a reductionnist because I don't work on the basis of the assumption that things should be reduced to their elementary components but that compnents make us understand things. In the contrary, I believe once we understand things on the basis of their components we should expand our knowledge by including larger components to things. For example, organisms or persons are not entities different from the world they live in. I believe that biological organisms and persons are embedded in a larger system which comprehends the physical and cultural environment they live in. Making ontological differences in the system can be useful to a certain point but I am mostly interested by the dynamics of the system and what results from it. It is rather a larger view and by looking at the system with this knd of view I feel authorized to view Language and Cars as technological tools taking part in the interactions going on inside the system without regard to their essence.

Thank you for your kind and critical comments.