Darwin’s Theory of Evolution AP Biology

Monday 3/7 at a Glance Howdy AP Bio, Sorry I’m out sick today. Due to this, quiz retakes will be possible through Wednesday 3/9.-Ms. Vazquez In class today: *Darwin Lecture *Intro. To Darwin Packet -Note: The Darwin game (packet p. 4) will happen later. Homework: Choose your own adventure, do ONE of the following: Read Section 21.1 (p )—take brief notes & answer CC #1- 3OR… Watch first 11 minutes of the lecture called “Genes, variation, and evolution” & take good notes!

Shaping Darwin’s Theory Carolus Linnaeus – Specialized in taxonomy – Came up with binomial system for naming organisms Homo sapiens – H. sapiens = human Escherichia coli – E. coli bacteria Georges Cuvier – Studied fossils (paleontology) Each deeper layer of rock contains different species The further away the layer the more dissimilar the fossils – Catastrophism James Hutton – Geological features (mountains, rivers, etc.) are the product of a slow but continuous process – Gradualism Charles Lyell – Uniformitarianism Geological processes seen today have not changed throughout Earth’s history … rate of mountain building is constant

Jean Baptiste Lamarck – Use and Disuse Body parts used the most will develop and those that aren’t used will waste away Blacksmith big biceps and long neck of giraffes – Acquired characteristics Modifications within own lifetime are passed on to offspring THIS DOES NOT HAPPEN Thomas Malthus – Much of human suffering is due to population increasing faster than food supplies and other resources allow Darwin applied this research to other life on earth

Meet Darwin Born in 1809 in England Studied science at Cambridge Thought about becoming a priest

Darwin and the Beagle What was the Beagle? – A research ship Darwin spent 5 years on a journey around the world. ( )

What did Darwin observe? Found fossils of animals that are now extinct. Glyptodont – Similar to armadillos today Darwin wondered how these animals might be connected.

Different Animals in Similar Climates Argentine Grasslands – Guanaco and tapir Australian Grasslands – Wallaby and wombat

Darwin’s Stop in the Galapagos

The Galapagos Islands Important stop on Darwin’s trip!

Important Galapago’s Animals Darwin collected birds from the island and studied them.

Darwin’s Theory of Natural Selection 1)Organisms reproduce others of their kind & more offspring are produced in nature than can survive to reproduce 2)There are variations (genetic differences) among offspring within a population 3)Some variations are favorable and allow individuals to survive & reproduce better 4)Over long periods of time, favorable adaptations are inherited by most of the population

Descent with modification All organisms are related through a common ancestor. Diverse modifications, or adaptations, emerged due to various habitats populated by members of the common ancestor. These “new” modifications help fit them to a specific way of life.

Evolutionary Tree of Elephant Family Evidence based on: – Fossils – Anatomy – Order of appearance – Geographical distribution

Artificial Selection Humans select the traits they want and breed those particular organisms to create new variations very quickly

Natural Selection in the Works! Insecticide-Resistance in Insects – The ones with the resistance gene survive and reproduce Antibiotic-Resistance in Bacteria – The ones with the “super-powered” plasmid survive and reproduce Drug-Resistant HIV

Evidence for Evolution There are 5 main pieces of evidence showing organisms have evolved

Fossil Record Shows a tremendous variety of organisms Organisms come and go Reconstruct changes of organisms Infer behaviors (ex: sharp teeth = carnivore)

Morphology Similar types of body structures Homologous Structures – Show common ancestry – Example: teeth of a bear and teeth of a dog – Example: arm of a human and flipper of a whale Analogous Structure – Common function but not a common anscestor – Example: wings of a bird and wings of butterfly

Biochemical and Molecular Same chemical makeup in biomolecules – Carbohydrates (sugars) – C,H,O – Proteins (amino acids) – C,H,O,N,S – Lipids (fats/oils) – C,H,O – Nucleic acids (DNA, RNA) – C,H,O,P The more similar the DNA sequence (A,T,G,G’s) or the protein sequence (amino acids), the more recently a common ancestor existed between two organisms Similar metabolic processes from humans to bacteria (same chemical reactions such as Glycolysis) Process of: DNA RNA protein is the same

Embryology Embryos of fish, lizards, turtles, chickens, pig, mice and humans are very similar. Embryonic pattern of development seems to be retained in many organisms.

Biogeographical data Organisms unique to a certain location that has been isolated for a long time. – Example: Madagascar has a variety of unique organisms (lemurs) Organisms with very similar body plans are found in different areas around the world. – Example: Flightless birds (kiwi, ostrich, rhea, emu, cassowary)