What is gradualism and punctuated evolution? Agenda for Monday Nov 15 th 1.Finish Fossil Lab 2.Theories of Evolution Notes: Lamarck 1.Lamarck’s Giraffes

Theories of Evolution Evolution – change in the inherited traits of a population of organisms over time 2 Main contributors – Lamarck and Darwin

Jean Baptiste de Lamarck Proposed similar species descended from a common ancestor Living species were descended from similar extinct species

Lamarck Use and disuse of organs – developing/changing structure and function of old organs Inheritance of acquired traits – Acquired trait – a trait that arises during the lifetime of an organism – acquired traits were passed on to the organism's offspring

Lamarck Organisms acquire traits and then pass these traits on to their offspring

Lamarck Right and Wrong Incorrect Not all traits acquired get passed on Important Introduced Evolution/change Realized organisms are changing

What was Lamarck’s Theory of Evolution? Agenda for Tuesday Nov 16 th 1.Theories of Evolution: Darwin 1.Lamarck’s Giraffes 2.Darwin’s Postulates

Darwin

Quit Medical School and became a naturalist H.M.S. Beagle – 5 year journey to survey Wrote The Origin of Species

Charles Lyell Wrote Principle of Geology Uniformitarianism Darwin – Habitats change slowly = requires organisms to adapt to these changes in order to survive

Galapagos Islands Darwin landed in the Galapagos Islands and noticed differences in animal species Drew and made observations while in the Galapagos Back in England he looked at his findings – Tortoises and Finches

Galapagos Islands Finches – collected 13 similar but separate species of finches – Each had a distinct bill (beak) Finches implied a shared recent common ancestor – Adapting to different environments Darwin reasoned over millions of years = many large differences

Darwin’s Theory Natural selection – organisms best suited for their environment reproduce more successfully than other organisms Over several generations organisms with favorable traits increase

Darwin’s Theories Descent with Modification Newer forms in the fossil record are modified forms of older species All species descended from one or a few original types of life

Darwin’s Theories Modification by Natural Selection Influenced by Thomas Malthus – Populations have the potential of doubling and redoubling their numbers – Human pop. have been limited by war, disease, etc. – Darwin noted most pop. have limited growth

Modification by Natural Selection Env’t affect individual organisms in different ways – natural selection Adaption – traits that enhance the survival and reproductive success – Resulting change in the genetic makeup of a population is evolution

2 types of Adaptations Camouflage and mimicry

Modification by Natural Selection An organism’s genetic contribution to the next generation is fitness – Greater fitness = better adapted to env’t = reproduces more successfully Favorable traits give organisms an adaptive advantage Environment “selects” traits – Favorable traits depend on demands of env’t

Postulate 1 Postulate 1 – Variation within a population

Postulate 2 Traits are inherited/passed on

Postulate 3 More offspring are produced than can survive

Postulate 4 Individuals with advantages traits survive

Summary of Darwin Inherit traits Natural Selection – organisms best suited/best adapted to the environment survive and reproduce – Adaptations

What is Natural Selection? Agenda for Wednesday Nov 17 th 1.Lamarck’s Giraffes Coloring 2.Darwin’s Postulates

What are Darwin’s Postulates of Evolution? Agenda for Thursday Nov 18 th 1.Go over Postulates Worksheet 2.Lab 3.Rat Island Evolution

Agenda for Friday Nov 19 th 1.Quiz 2.Galapagos Islands Video