As natural selection acts by life and death, by the survival of the fittest, and by the destruction of the less well-fitted individuals, I have sometimes felt great difficulty in understanding the origin or formation of parts of little importance;
Hautespen naturalak biziaz eta heriotzaz-egokienen biziraupenaz eta egokitasun eskasena dutenen suntsipenaz-, jokatzen duenez gero, zailtasun handia nabaritu izan dut batzuetan, garrantzi txikiko atalen sorrera edo formakuntza ulertzeko;