December 3, 2010

Allen Buchanan: "Breaking Evolution's Chains" [CFI conference on biomedical enhancements]

Bioethicist Allen Buchanan is today's first presenter. His talk is entitled, "Breaking Evolution's Chains." Buchanan is a co-author of the book, From Chance to Choice: Genetics and Justice, which is a must-read in enhancement bioethics.

Buchanan is talking specifically about genetic modifications. His concern is the "ubiquity of suboptimal design in Unintentional Genetic Modifications (UGM)." Buchanan makes the distinction between UGM and IGM (Intended Genetic Modifications).

Darwin showed that we can explain evolution and diversity without design. Buchanan shows the audience a lengthy list of examples of poor human "design," including human inability to biosynthesize Vitamin C, our poor sinus, human birth canal, lower back, pharynx (dual function, ingestion/respiration--risk of death by choking), urinary tract in male mammals (passes through, not around prostate), etc.

Why is suboptimal design ubiquitous? Answers include insensitivity of natural selection to post-reproduction quality of life, hence cardiovascular degeneration, cancer, degeneration of muscles and joints, neural degenerations, and other aging related disorders.

In UGM, selection does not imply optimality -- it says nothing about the current relation to reproductive fitness. Purely backward looking. Optimality depends on fit between organism and environment (where the environment is constantly changing). So, optimality is fleeting, always changing.

What was optimal may now be fatal. Not a progressive kind of thing at all. What's optimal in evolution may not be aligned with human values. Also, under UGM, spread of desirable mutations may be too slow and too great a cost in human terms; little lateral gene transfer. Another problem of "evolution as usual" are "Pleistocene Hangovers" -- what was adaptive in the EEA may now be maladaptive (e.g. propensity to xenophobia, step-child abuse, attention deficit 'disorder'.

Master engineer? Fickle, morally blind, tightly-shakled tinkerer. Doesn't finish projects, discards much of value. Doesn't aim at human good, achieves it only by coincidence; methods have high moral costs.

Problems with the Master Engineer analogy: (a) making risky changes in the name of improvement and (b)
resting content with the status quo. But in UGM the status quo is constantly changing, precarious.

The existing human organism is not finely balanced, stable, completed product that will continue as is, absent deliberate intervention.

"We may have to enhance, in order to conserve the goods we have."

Possible examples:
  • Enhanced reproduction to counteract drastic decline in fertility due to environmental toxins
  • Enhancement of resistance to skin cancer if ozone layer depletes
  • Cognitive and/or affective enhancements to deal with global scale problems
Bioconservatives: the individual organism is like a seamless web. Traditional social conservatives: Society is like a seamless web. Both imply fragility: Cut one thread and the whole thing may unravel. 

Evidence against seamlessness: modularity of design, redundancy of systems, canalization ("you can make the same dish using different recipes"), natural selection requires incrementalism--being able to change one trait without changing the others. 

The worry about unintended consequences: How can we take the worry seriously? And get beyond vague platitudes like "use caution", "take it slow", etc. We need something more substantive, heuristic based. Otherwise it's too vague. 

Strategy: Take the hardest case: Unintended bad consequences of IGM (germline enhancements). Think about scientifically informed responses. 

Think ontogeny. Has to be sensitive to the ontogenic process. That's the key.

Evolutionary precautionary heuristics for IGM (as opposed to the precautionary principle). 
  • The IGM targets genes that lie "downstream" rather than "upstream" in the organism's developmental process
  • If successful, would not produce an enhancement that exceeds the upper bound of the current normal range (e.g. boost in cognitive performance beyond anything any human has ever had)
  • Effects are containable within the organism 
  • Involves a highly modularized system of or subsystem of the organism (mistakes can be contained within that modular)
  • Effects are reversible
  • Intervention does not require major morphological changes
  • If goal is to eliminate a trait, then the causal roles of the trait and of the genes targeted for elimination should be well understood
There is good reason to worry about unintended bad effects of BE in general and of IGM in particular. Reasonable precautions should be based on accurate understanding of evolution, not faulty metaphor of Master Engineer. 

A plurality of precautionary heuristics should change over time. 

The threat of loss of normal human capacities. Pseudogenization of genes needed for normal human capacities (e.g. loss of bitter taste receptors as a result of cooking food, loss of visual acuity, loss of ability to biosynthesize Vitamin C). If selective pressures are eased, mutations increase to the point of making a gene nonfunctional and the associated capacity is lost.


Buchanan is essentially "paving the way" for more substantive enhancements; we have to start where we are and in a responsible way.

What's possible and what's sci-fi fantasy? Risky to make predictions. Not confident that we'll be able to conduct meaningful IGM for various reasons.

How can we ever test IGM and go about the ethics of experimentation? More animal testing; need to know more about genetics and implications of modifications; but we shouldn't be complacent about the status quo -- it may be more reasonable or ethical to tolerate a little bit of risk. 

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