evidence of evolution the genetic changes in a species over time

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Slide 2 Evidence of Evolution Slide 3 The genetic changes in a species over time Slide 4 What evidence is there of the theory of evolution? Slide 5 Fossils Comparative anatomy Embryology Biochemistry/genetics Slide 6 any trace or remains of an organism that has been preserved by natural processes Slide 7 Indirect evidence left by an organism Can be footprints, burrows, and fossilized feces Moving through sediment as they move on the ocean bottom while feeding 5 toed lizard- like marks Slide 8 Impression of an organism Mold An empty space left in a rock when an organism dies and decays Cast Minerals fill in empty space of mold and harden in the same shape of the organism which used to be there Slide 9 Cast (above) Mold (below) Found in 1983. Only footprint found of the T-rex Slide 10 Petrified Original material of organism replaced by minerals Slide 11 Amber entire organisms are preserved in resin (from trees), which turns into amber Slide 12 Ice in the Arctic, entire organisms have been found preserved in ice Slide 13 Slide 14 Bones sometimes the mineral parts, like teeth and bones, of animals are preserved Slide 15 Modern whales (land to sea) Giraffes Elephants Horses Mollusks Suggest new species evolved from and replaced previous species Slide 16 Slide 17 Slide 18 Fossils can be big or small A fossil will only form under a precise combination of conditions Many animals die without leaving fossils Incomplete evidence in the fossil record Fossils form in sedimentary rock Layers of sediment build up on top of the dead organism to eventually form rock Slide 19 Provides evidence about the history of life on Earth. Shows how different groups of organisms, including species changed over time Slide 20 Most fossils are found in sedimentary rock. Law of Superposition Law of Superposition oldest layers are at the bottom; youngest layers are on the top Slide 21 Slide 22 Slide 23 relative dating is a method of determining the order in which events occurred; does not give the precise age of a fossil. absolute dating is a method that determines the actual age of the fossil Slide 24 fossils that permit the relative dating of rocks within a narrow time span Example: trilobites Slide 25 Correlation: matching layers of sedimentary rock to show relationships among organisms from different regions Slide 26 Is the length of time required for half of the radioactive atoms in a sample to decay Radioactive dating the use of half-lives to determine the age of a sample Certain rocks have radioactive elements in them that decay at a steady rate Slide 27 Carbon-14 is taken up by living things while they are alive Carbon-12 is also in an organism but it does not decay Scientists can compare the amount of Carbon-14 to the amount of Carbon-12 to determine the age of the sample based off Carbon-14s half-life of 5,730 years Slide 28 Carbon-14 has a short half-life and can only be used on samples that are younger than 60,000 years old Potassium-40 and Argon-40 have half-lives of 1.26 billion years (check to see if these ones are used) Slide 29 3 things you learned 2 things you found interesting 1 question you still have Slide 30 What are three ways an organism can be preserved? Slide 31 Fossils Comparative anatomy Embryology Biochemistry/genetics Slide 32 Comparative anatomy: study of structural similarities and differences among living things. Slide 33 Parts of different organisms that have similar structures, but different functions. Homologous structures are evidence that some species evolved from a common ancestor!!!. Slide 34 Human Whale CatBat Bird Slide 35 Analogous structures have similar functions, but different internal structure. Ex.) wings of insects and birds Slide 36 Slide 37 When natural selection causes non- homologous structures (not the same) to have similar functions that resemble one another Slide 38 Slide 39 Structures that are in organisms but have reduced in size and serve little or no function human body has more than 100 vestigial structures Slide 40 Slide 41 Slide 42 Slide 43 Slide 44 Slide 45 Slide 46 Slide 47 Slide 48 Slide 49 Define: Vestigial structure, Homologous Structures, and Analogous structures Slide 50 Fossils Comparative anatomy Embryology Biochemistry/genetics Slide 51 The study and comparison of the early stages of development of different species. These similarities suggest a common ancestor. Slide 52 Fish Chicken PigHuman Slide 53 Slide 54 In the early embryotic stages, fish, turtles, chickens, mice, and humans all develop tails and gill slits. ONLY FISH, TURTLES AND MICE RETAIN SUBSTANTIAL TAILS ONLY FISH HAVE GILLS Slide 55 The answer is in the genes of their ancestor The similarities in the embryo mean that the ancestral vertebrates possessed genes that that produce tails and gills Since they have those genes they will develop in a similar way during the early developmental stages Slide 56 Fossils Comparative anatomy Embryology Biochemistry/genetics Slide 57 DNA is the genetic material found in ALL living organisms. The more closely related species are to one another, the greater the similarity in DNA. Slide 58 The ability to quickly determine the sequence of nucleotides in a DNA molecule is a relatively new technology If scientists know the sequence of nucleotides of one organism they can compare it to the sequence of another organism Slide 59 Slide 60 The protein cytochrome c is present in the cells of all plants, all animals, and many single-celled organisms and performs the same function. This suggests that these diverse organisms share a common ancestor that had cytochrome c in its cells Slide 61 Describe how embryology, analogist structures, and homogeneous structures are used to explain evolution Slide 62 The origin of life is not completely understood, but genetic and structural evidence suggests that all life on Earth has a remote common ancestor Slide 63 the geologic time scale is the earths history. 4 major eras: 1. Precambrian (oldest) 2. Paleozoic(age of invert., fish, and amphibians) 3. Mesozoic(age of reptiles) 4. Cenozoic(age of mammals and humans)most recent Geologic Time Scale Slide 64 The belief that life can come from nonliving matter. Ex: rotting meat gives rise to maggots. The Theory of Spontaneous Generation Slide 65 provided evidence AGAINST spontaneous generation in a series of experiments. Francisco Redi Slide 66 placed different kinds of meat in open jars. maggots appeared on the meat. Slide 67 The maggots developed from the eggs laid on the meat by the flies. Slide 68 placed meats in tightly sealed jars. no maggots appeared on the meat! Slide 69 setup jars covered with gauze to allow air in, but keep flies out. NO MAGGOTS APPEARED ON THE MEAT! Third Part: Slide 70 Slide 71 father of microbiology and its effect on life. In 1864, he used a broth and boiled the substance. Disproved the theory of spontaneous generation. He hypothesized that water alone could not produce microorganisms Slide 72 Slide 73 Biogenesis: idea that living things arise from other living things. The question still remained--- Where did the first life forms arise from, and how did the first life forms inhabit the Earth? Slide 74 Earths first atmosphere contained: H 2, H 2 0, ammonia (NH 3 ) and methane (CH 4 ). Temperature was extremely hot. What is missing? No oxygen! NO photosyn./aerobic resp. Slide 75 Slide 76 the synthesis of organic compounds from inorganic raw materials requires energy. 1953-Stanley Miller and Harold Urey recreated the primitive Earth environment What gasses were present? he then exposed the environment to electric sparks (simulated lightning). Slide 77 Slide 78 In a few days, organic molecules started to form. With constant energy and enough time (millions/billions of years), organic molecules form. Slide 79 clusters of organic molecules within them chemical reactions occurred released energy (anaerobic respiration) obtained nutrients from the environment (heterotrophs) Grew in size (growth) Split in half (reproduction) considered the first life forms. Slide 80 Slide 81 The idea of how the first life forms originated on Earth. First life forms were anaerobic heterotrophs--- that is they obtained food from the environment. Slide 82 no free O 2 the first organisms-- anaerobic respiration. It increased level of CO 2 Slide 83 ~3.5 bya organisms evolved that were able to capture light energy. This released oxygen in to the air. Slide 84 Organisms use light energy and CO2 for photosynthesis This process added O 2 into the atmosphere Now Aerobic Respiration could take place Slide 85 ANAEROBIC HETEROTROPHS Added CO 2 to the air ANAEROBIC AUTOTROPHS Added O 2 to the air AEROBIC HETEROTROPHS AEROBIC AUTOTROPHS

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