TB: Hacking Darwin (Metzl)
Core Thesis
The principles of Darwinian evolution are themselves evolving. Genetic technologies — IVF with preimplantation screening, CRISPR editing, whole-genome sequencing — are moving humans from passive recipients of evolution to active engineers of it. The question is not whether this will happen but how to govern it.
Key Takeaways
The biology baseline
- 3.8B years ago single-cell organisms emerged. Sex was invented ~1.3B years ago, dramatically accelerating evolution.
- Humans have ~21,000 genes, 3.2B base pairs. Epigenetics regulates how DNA is expressed — lifestyle choices significantly affect epigenetic instructions.
- 37 genes are in the mitochondria, inherited maternally.
- Most cells turn over roughly every two years on average.
Genetic technologies
- Sperm and eggs have been generated from skin cells and used to produce healthy mice.
- Scientists have produced viable offspring from two male mice.
- Arctic apples: CRISPR-silenced browning genes — a preview of routine agricultural editing.
- We will never have perfect knowledge of the genome, just as we never had perfect knowledge of fire before harnessing it, or cancer before treating it.
The coming transition
- Generalized medicine (based on population averages) will come to be seen as the equivalent of leeches.
- Conception through unassisted sex will increasingly be seen as unnecessarily risky when embryo screening is available.
- 28-year human generation time can be partially circumvented by breeding preimplanted embryos with each other.
Aging and death
- Aging is the leading cause of death — diseases that kill us most are diseases of aging. Curing any one disease (e.g., cancer) buys only ~3 additional years.
- Aging is probably a combination of many different systems decaying at different rates.
Ethics and diversity
- Eugenics killed or sterilized hundreds of thousands in the US and Nazi Germany. Diversity has been and remains the sole survival strategy of our species.
- Bostrom's Reversal Test: if you object to a change in one direction, you must articulate why the opposite (active) change would be unjustified.
- Optimism and hubris are built into our operating systems — important to recognize when designing governance.
Mental Models
- Inversion — Bostrom's Reversal Test is an inversion: if opposing X, explain why −X is worse