Mechanisms of Change Selection Types of Evolution Macroevolution

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Mechanisms of Change: Selection

Mechanisms of Change: Selection

Types of Evolution Macroevolution change of one kind of organism into another “macro” =

Types of Evolution Macroevolution change of one kind of organism into another “macro” = large this has not been observed, but is assumed in the current evolutionary theory

Types of Evolution – cont’d Microevolution small changes in organisms through selection “micro” =

Types of Evolution – cont’d Microevolution small changes in organisms through selection “micro” = small has been observed is assumed in current evolutionary theory to accumulate until a large change is seen

Discuss Explain the difference between macro- and micro- evolution

Discuss Explain the difference between macro- and micro- evolution

Selection Example to be used: A colony of clams lives at a particular beach.

Selection Example 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 rock underneath. The beach contains areas of light, dark and intermediate sand in various amounts.

Natural Selection – organisms which have the best-suited traits survive in their environment

Natural Selection – organisms which have the best-suited traits survive in their environment

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive Four types: directional selection one extreme of a trait is best and is selected

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive Four types: disruptive selection multiple extremes of a trait are best and are selected

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive Four types: stabilizing selection intermediate/average form of trait is selected

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive

Natural Selection – cont’d Natural Selection – organisms which have the bestsuited traits survive I made these Four types: just for YOU! La la laaaaaa!!!!!! sexual selection presence of a trait influences mating trait can be physical OR behavioral

Darwin’s 5 points 1. 2. 3. 4. 5. Population has variations. Some variations are

Darwin’s 5 points 1. 2. 3. 4. 5. Population has variations. Some variations are favorable. More offspring are produced than survive Those that survive have favorable traits. A population will change over time.

La. Marck’s Theory Jean Baptiste La. Marck: 1800’s Believed: Change Occurs Over Time inheritance

La. Marck’s Theory Jean Baptiste La. Marck: 1800’s Believed: Change Occurs Over Time inheritance of acquired characteristics acquired changes were passed to offspring Law of Use and Disuse If a body part were used, it got stronger If body part NOT used, it deteriorated Examples: Body builders or pierced ears

Discuss Name and describe the four types of natural selection. Give an example of

Discuss Name and describe the four types of natural selection. Give an example of each type of selection [NOT my example – pick another]

Artificial Selection – humans select desirable traits and breed out non-desirable traits crop farming

Artificial Selection – humans select desirable traits and breed out non-desirable traits crop farming

Artificial Selection – cont’d Artificial Selection – humans select desirable traits and breed out

Artificial Selection – cont’d Artificial Selection – humans select desirable traits and breed out non-desirable traits animal breeding

Discuss What is the difference between natural and artificial selection?

Discuss What is the difference between natural and artificial selection?

Selection – cont’d Selection works on POPULATIONS not on individuals we do not select

Selection – cont’d Selection works on POPULATIONS not on individuals we 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

Homework Complete the Darwin’s Five points worksheet title of worksheet = “Natural Selection”

Homework Complete the Darwin’s Five points worksheet title of worksheet = “Natural Selection”