Upload
adrian-brooks
View
217
Download
4
Tags:
Embed Size (px)
Citation preview
Unit 5 – Lecture 3
Types of EvolutionMacroevolution
change of one kind of organism into another“macro” = largethis has not been observed, but is assumed in
the current evolutionary theory
Types of Evolution – cont’dMicroevolution
small changes in organisms through selection“micro” = smallhas been observedis assumed in in current evolutionary theory to
accumulate until a large change is seen
Discuss
Explain the difference between macro- and micro- evolution
SelectionExample to be used:
A colony of clams lives at a particular beach. These clams come in three varieties – white, grey, and black. Grey is, of course, an intermediate color between the two extremes, white and black. These clams are a part of a sea-bird’s natural diet – however, they are unable to see the clams well which blend into the background of the sand and rock underneath. The beach contains areas of light, dark and intermediate sand in various amounts.
Natural SelectionNatural Selection – organisms which have the
best-suited traits survive in their environment
Natural Selection – cont’dNatural Selection – organisms which have the
best-suited traits surviveFour types:
directional selectionone extreme of a trait is best and is
selected
Natural Selection – cont’dNatural Selection – organisms which have the
best-suited traits surviveFour types:
disruptive selectionmultiple extremes of a trait are best and
are selected
Natural Selection – cont’dNatural Selection – organisms which have the
best-suited traits surviveFour types:
stabilizing selectionintermediate/average form of trait is
selected
Natural Selection – cont’dNatural Selection – organisms which have the
best-suited traits surviveFour types:
sexual selectionpresence of a trait influences mating trait can be physical OR behavioral
La la la la la la la la
laaaaaa!!!!!!
I made these just for YOU!
Discuss
Name and describe the four types of natural selection.
Give an example of each typeof selection [NOT my example –
pick another]
Artificial SelectionArtificial Selection – humans select desirable
traits and breed out non-desirable traitscrop farming
Artificial Selection – cont’dArtificial Selection –
humans select desirable traits and breed out non-desirable traitsanimal breeding
Discuss
What is the difference betweennatural and artificial selection?
Selection – cont’dSelection works on POPULATIONS not on
individualswe do not select the best corn plant just to
plant one seed and make one plant!!just so, one animal with new
characteristics must cause change to the entire population for it to make a difference
HomeworkComplete the Darwin’s Five points worksheet
title of worksheet = “Natural Selection”
Label your MATERIALS check list with 2/8material = 3 Tabs
Take our your transcript, I will call you up in a minute.