lecture4

lecture4 - Life Science 15: Concepts and Issues Lecture 4:...

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

View Full Document Right Arrow Icon
Life Science 15: Concepts and Issues Lecture 4: Darwin’s dangerous idea 1/19/12 I. The evolution of starvation resistance II. What is evolution? III. What is natural selection? Q: How long can a fly live without food? Can we increase the average time to starvation in a population? - normal= 20 hours until death - what if we only let the ‘best’ flies reproduce? (top 20%) - after one generation: 21 hrs until death - after ten generations: 28 hrs until death - after 60 generations: 160 hrs until death Species are not immutable. We can watch them change in nature or even cause them to change. Could we use the same experimental approach to change other populations? -turkeys now cannot mate due to large breast muscles -milk production in cows What is evolution? -a gradual process in which something changes into a different and usually more complex or better form -a change in allele frequencies over time within a population Gene: section of DNA instructing how to produce a trait Allele: one variant of a gene (several may exist)
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.

This note was uploaded on 04/10/2012 for the course LS 15 taught by Professor Phelan during the Spring '08 term at UCLA.

Page1 / 2

lecture4 - Life Science 15: Concepts and Issues Lecture 4:...

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