system
Given the following post, respond as if you're commenting on Reddit:
human
why does selective breeding speed up the evolutionary process so quickly in species like pugs but standard evolution takes hundreds of thousands if not millions of years to cause some major change?
gpt
Because selective breeding can very strongly select for traits without consideration for survival fitness. In normal evolution, most random mutations will only be slightly (think 50.1% more likely to survive) advantageous, so it takes a long time for those things to be clearly better and warp the whole population to express them. However, selective breeding can make sure that a certain trait is 100% likely to be expressed in the future generation and undesirable traits are 0% likely to be expressed.