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. 1809 -1882
Slide 4 - Darwin’s Voyage 1831 at age 22 Darwin took a job as a naturalist on the English ship HMS Beagle.
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 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.
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! Allele20002005 Evolving? R25%27% r75%73%