Lecture 3- Mutations - Lecture 3: Mutations 2/13/08...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 3: Mutations 2/13/08 Evolution A species’ genetic component changes as the individuals reproduce due to… Non-random changes (natural selection): some individuals are better at passing on their genes than others Random changes (genetic drift/bottleneck) Mutations add new alleles or genes Evolution can occur randomly, by genetic drift o 1 st generation: Several individuals…RR, Rr, and rr…if everybody passed on genes or if everyone had same genes then evolution wouldn’t take place. Not everyone individuals and there’s different genes/traits. o 2 nd generation: Only 5 out of 10 from 1 st generation left offspring (only the RR’s could reproduce). .theres still a mix o 3 rd generation: only 2 from previous generation could reproduce, so everyone is RR. .same phenotype and genotype o Change in traits and change in DNA of species (due to evolution) o Random chance that only some could reproduce…has nothing to do with genotype…changes occur (not because something is advantageous or disadvantageous). If everyone reproduces at same rate, genetic drift. o If the RRs have an advantage and are better able to reproduce, then this is natural selection . o The evolutionary outcome is similar: changes in traits as reproduction takes place…it’s the reason behind why the traits change that determines whether its natural selection or genetic drift Other random evolution: Bottleneck o Original population: imagine a bottle filled with lots of purples, lots of whites, some yellows….bottlenecking event happens…only a few individuals survive (the ones that pour out of bottle). Criteria still the
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

Lecture 3- Mutations - Lecture 3: Mutations 2/13/08...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online