KERA's Think Why we’ll never evolve to be perfect
May 12, 2025
Laurence D. Hurst, a professor of evolutionary genetics at the University of Bath and author of 'The Evolution of Imperfection,' dives into the fascinating world of human genetics. He reveals that our high mutation rate guarantees we’ll never achieve perfection. The discussion includes the differences in how humans and other species manage 'junk DNA,' the implications of genetic diversity, and the surprising realities of early pregnancy losses. Hurst highlights how evolution is more about adaptation than flawlessness, leaving us with a mix of marvel and mutability.
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Human Genetic Imperfections Revealed
- Humans exhibit high genetic abnormalities early in development, with 40-60% of fertilized eggs having the wrong chromosome count.
- Most embryos with abnormalities die early, explaining high miscarriage rates and showcasing genetic imperfections.
Human DNA Loaded with Junk
- About 90% of human DNA is non-coding 'junk' DNA, mainly remnants of jumping genes and viruses.
- Other species clear junk DNA more efficiently, making human DNA less optimized evolutionarily.
High Mutation Rate Harms Humans
- High mutation rates generally harm an organism as random DNA changes are more likely to be damaging than beneficial.
- Humans have one of the highest mutation rates recorded, impacting genetic health negatively.