Presentation on theme: "Evolution. Slide 1 - Evolution Change in species over."— Presentation transcript:
Slide 1 - Evolution Change in species over.
Slide 2 People used to believe: Species are designed by a divine creator (aka god) and are fixed/unchanging and perfect. False belief Earth is only 6000 years old. Earth is actually 4.5 Billion Years Old.
Slide 3 Charles Darwin and Evolution s
Slide 4 - Darwin’s Voyage 1831 at age 22 Darwin took a job as a naturalist on the English ship HMS Beagle.
Slide 5 - Darwin’s voyage on the Beagle
Slide 6 - Galapagos Islands Species were unique but similar to species elsewhere.
Slide 7 - Galapagos Tortoise
Slide 8 - Galapagos Iguana
Slide 9 - Galapagos Finches
Slide 10 - Species Similar traits and can mate and produce fertile offspring. But species within a population are different in some way.
Slide 11 Natural Selection What causes evolution!
Slide 12 - Peppered Moths Birds eat peppered moths! What moth has the advantage? What moth population will be larger?
Slide 13 - Industrial Revolution Covered trees and buildings with soot making them dark. Now which population is favorable? Dark or white?
Slide 21 - Homologous Structures Homo = Same Same structures between species. Come from common ancestor!
Slide 22 - Analogous Structures Similar in function but not from common ancestor (e.g. Do bugs’ wings have bones like birds? No).
Slide 23 Homology Versus Analogy
Slide 24 - Vestigial Structure A body structure in a present-day organism that no longer serves its original purpose, but was probably useful to an ancestor.
Slide 25 - Stop and Think! What’s a vestigial organ in humans?
Slide 26 Vestigial Structure Examples: Mole Rat Ostrich
Slide 27 - Embryo
Slide 28 - Embryology Embryos have same structure among different species.
Slide 29 - Can you tell which will become a chicken? Cat? Bat? Snake? Human? Possum?
Slide 30 - How about now?
Slide 31 - Now??
Slide 33 - Biochemistry Some organisms have similar DNA sequences.
Slide 34 - For Example: Versus Chimpanzee Gorilla
Slide 35 - For Example: Versus Chimpanzee Rose Bush
History of Earth
Slide 38 - Geologic Time Scale Sequence of events from Earth’s birth to present-day (now). Four main eras: 1. Precambrian (Earth Born) – First life evolved 2. Paleozoic – Plants evolved. 3. Mesozoic – Dinosaurs evolved 4. Cenozoic (Present – day) – Humans evolved
Slide 39 - When Earth was born No life existed. SurfaceSo hot all of Earth was melted rock! AtmosphereNo O2 because no plants existed yet! Only gasses from outgassing (Volcanoes erupting). OceansNo liquid water. Too hot! Everything was Water vapor.
Slide 40 -Where did O2 come from? Photosynthesis from plants!
Slide 41 - Rocks Where fossils are found!
Slide 42 - Fossil Anything left from a living organism.
Slide 45 - Fast Fact! About 99% of species that have lived on Earth are extinct.
Slide 46 - How old are fossils? Relative Dating Fossils found in layers closer to the surface are younger than the deeper layers. Radiometric Dating Measuring how much of an element is still present in a fossil, using the half life.
Slide 47 - Half Life Amount of time it takes for a radioactive element to decrease by half.
Slide 48 - Paleontologist Person who studies fossils. Size of Animal How they moved What they ate. What climate they lived in. When organisms lived.
Slide 49 - Plate Tectonics Crust floats on the mantle which is composed of molten (melted) rock. Crust is divided into plates! Constantly moving (1-10 cm/year)
Slide 50 - Pangaea “All Land” All continents were once joined together.
Slide 51 - Pangaea Separated Laurasia and Gondwana
Slide 52 - Earth Today As continents moved species became isolated and started to evolve differently.
Slide 53 - Stop and Think Someone find a fossil of a polar bear that lived a billion years ago in Hawaii. What was the latitude of Hawaii a billion years ago?
Slide 54 - Australia Since it is so isolated from any other land, it has very unique species.
Slide 55 - Fossil Record Ordered levels of fossils in rock. Indicates that organism have evolved in sequence.
History of Life
Slide 57 - Overview Small Organisms = Bacteria (microscopic) Large Organisms = Non-microscopic (flies, humans, etc.)
Slide 58 Spontaneous Generation (SG) False idea that non-living things can produce life. Life “spontaneously” appears.
Slide 59 - Francisco Redi Proved Spontaneous Generation was wrong with a fly experiment.
Slide 64 - Biogenesis Living organisms come from other living organisms.
Slide 65 - So where did the first life come from?
Slide 66 - Biomolecules Bio = Life Molecules made by living things! Proteins (Muscles and Bone) Carbohydrates (Sugar) Nucleic Acids (DNA and RNA) Lipids (Fat)
Slide 67 - Alexander Oparin’s Hypothesis How Biomolecules formed. Lightning hit the atmosphere of early earth (ammonia, water vapor, methane, hydrogen gas) and caused amino acids to form.
Slide 68 - Stanley Miller and Harold Urey Tested Oparin’s Hypothesis and found that it worked!
Slide 70 - Speciation: When a species changes so much it evolves into a new species.
Slide 71 - Gene Pool: All the alleles in a population.
Slide 72 - Allelic Frequency The Percentage of any specific allele in the gene pool. Allele# of Alleles in Population Allelic Frequency R55/20 = ¼ = 25% r1515/20 = ¾ = 75% Total Alleles in population = 20
Slide 73 - Genetic Equilibrium When % of alleles does not change. Population is NOT evolving! Allele Evolving? R25%27% r75%73%