Natural selection often favors traits that maximize reproductive fitness, even if it pushes them to a dangerous peak where a small step further leads to catastrophic failure. This "cliff edge" model helps explain disorders like schizophrenia or childbirth complications, where genes beneficial in moderation can be disastrous in excess.
Contrary to viewing adversity's effects as mere dysfunction, an evolutionary lens suggests they are adaptations. For example, accelerated puberty in response to a threatening environment increases the chances of passing on genes, prioritizing reproduction over long-term health, neatly summarized as 'live fast and die young.'
Humans evolved to have different "drugs of choice" as a survival mechanism. If everyone sought the same rewards, groups would quickly deplete a single resource. This once-adaptive trait now makes us vulnerable to a wide array of modern, hyper-stimulating temptations.
Mathematical models of evolution demonstrate a near-zero probability that natural selection would shape sensory systems to perceive objective truth. Instead, our senses evolved merely to guide adaptive behavior, prioritizing actions that lead to survival and reproduction over generating an accurate depiction of the world.
The success of iterative design processes hinges entirely on the metric being measured. An enzyme evolved for temperature stability won't necessarily remove clothing stains unless stain removal is the specific property being screened for. This highlights the critical importance of defining the right success metric from the start.
The MET-MET gene, which causes slower clearance of adrenaline, isn't a simple hindrance. It's a trade-off. It makes you less resilient to chaos ("a poor soldier") but exceptional at focused, obsessive work ("a good coder"). This genetic makeup is a finely-tuned system that excels under stable conditions but struggles under high stress.
Fears about unintended trade-offs from embryo selection are largely unfounded due to 'positive pleiotropy.' The genes for many diseases are positively correlated. This means selecting against a disease like severe depression often provides a 'free' reduction in the risk of other conditions like bipolar disorder and schizophrenia.
We age because natural selection favors genes that provide benefits early in life (e.g., faster growth, stronger immune response), even if those same genes cause deterioration later. Aging is the price we pay for traits that maximize reproductive success in our youth, not a fundamental law of biology.
Just as a blind person's visual cortex is repurposed for heightened hearing and touch, savantism might be an extreme case of this principle. An individual may develop superhuman skills by allocating a disproportionate amount of neural resources to one area, often at the cost of others like social skills.
Humans are biased to overestimate downside and underestimate upside because our ancestors' survival depended on it. The cautious survived, passing on pessimistic genes. In the modern world, where most risks are not fatal, this cognitive bias prevents us from pursuing opportunities where the true upside is in the unknown.
In restrictive environments where choices are limited, genetics play a smaller role in life outcomes. As society provides more opportunity and information—for example, in education for women or food availability—individual genetic predispositions become more significant differentiators, leading to genetically-driven inequality.