BIO120H1 Lecture Notes - Lecture 5: Genetic Drift, Heritability, Antimicrobial Resistance

• School: UTSG
• Department: Biology
• Course: BIO120H1
• Professor: Spencer C H Barrett

Document Summary

Everywhere we look in nature, we see animals that seem beautifully designed to fit their environment, whether that environment be the physical circumstances of life (temperature, humidity) or other organisms (competitors, predators, prey) Natural selection is everywhere -> scrutinizing individuals, culling the unfit, promoting the genes of the fitter. Natural selection can change the genetic composition of a population therefore increasing the proportion of genetic variants that enhance survival and reproduction (ex: coat colour in wild mice) Selection is a process/description of how genes that produce better adaptations become more frequent over time. Adaptation to the environment is inevitable if a species has the right kind of genetic variation. Evolution by selection is a combination of randomness (mutations-generate an array of genetic variants) and lawfulness (natural selection-orders this variation by keeping the good) It is the filtering of that variation by natural selection that products adaptation, it does not happen by chance.