Developing the Theory of Evolution Chapter 16 Developing the Theory of Evolution

How did life start ?

Origins: Early Ideas Spontaneous Generation Spontaneous Combustion Redi – Redi Experiement Rejected mid-1800’s Spontaneous Generation Theory of Biogenesis Louis Pasteur Only living organisms can give rise to other living organisms.

Origins: Modern Ideas Primordial Soup? Oparin & Haldane 1920’s Earth’s Atmosphere Mix of gases Lightning – energy source

Origins: Modern Ideas Photosynthesizing Prokaryotes Cellular Evolution First Cells – Prokaryotes Modern prokaryotes – archaea Live in extreme environments Photosynthesizing Prokaryotes Oxygen absent til 1.8 bya Produced oxygen Ozone layer Improved conditions for Eukaryotic cell development

Origins: Modern Ideas Miller-Urey Experiment Organic molecules could be produced from gases.

3 World Changing Biology Experiments

Origins: Modern Ideas Endosymbiont Theory Eukaryote “ate” prokaryote or bacteria Formed symbiotic relationships Prokaryote became the mitochondria Bacteria became chloroplasts Video Widely endorsed – do not know exact early steps.

Lamarck’s Theory of Evolution Inheritance of acquired characteristics Proposed that by selective use or disuse of organs, organisms acquired or lost certain traits during their lifetime These traits could then be passed on to their offspring Over time this led to new species

Lamarck’s Theory of Evolution Use & Disuse – Organisms could change the size or shape of organs by using them or not using them Blacksmiths & Their Sons (muscular arms) Giraffe’s Necks (longer from stretching)

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If Lamarck was right, then you should be able to work out and have stronger kids

Lamarck’s Mistakes Lamarck Did NOT Know how traits were inherited (Traits are passed through genes) Change Through Mutation Occurs Before An Organism Is Born

Charles Darwin (1809 – 1882)

copyright cmassengale Voyage of the Beagle Charles Darwin Born Feb. 12, 1809 Joined Crew of HMS Beagle, 1831 Naturalist 5 Year Voyage around world Avid Collector of Flora & Fauna Astounded By Variety of Life copyright cmassengale

Darwin returned 5 years later in 1836 Darwin Left England in 1831 Darwin returned 5 years later in 1836

The Galapagos Islands Small Group of Volcanic Islands 1000 km West of South America Very Different Climates Animals On Islands Unique Tortoises Iguanas Finches

The Galapagos Islands Island species varied from mainland species & from island-to- island species Each island had long or short neck tortoises

The Galapagos Islands Finches on the islands Resembled a mainland finch More types of finches appeared on the islands where the available food was different (seeds, nuts, berries, insects…) Finches had different types of beaks adapted to their type of food gathering

Darwin’s Observations Patterns of Diversity Unique Adaptations Species Not Evenly Distributed Australia, Kangaroos, but No Rabbits S. America, Llamas

Definition Evolution is the slow , gradual change in a population of organisms over time.

Publication of “On The Origin of Species” Upon His Return To England, Darwin Developed His Observations Into The Theory of Evolution

Darwin Finch Activity Part 1 Darwin’s Finches Darwin Finch Activity Part 1

Darwin Finch Sort Activity Darwin’s Finches Darwin Finch Sort Activity

Darwin’s Finches The Beak of the Finch

Darwin’s Finches Sorting Finch Species

What Darwin Never Knew

What Did T-Rex Taste Like?