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JRMG Bio1 2009. Evolutionary Evidences. Fossil Record and Geology Morphology Embryology Biochemistry Biogeography/ Geographical Distribution. Evidences. Fossils relics or impressions preserved because the material that surrounds the organism prevents it from decaying
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JRMG Bio1 2009 Evolutionary Evidences
Fossil Record and Geology Morphology Embryology Biochemistry Biogeography/ Geographical Distribution Evidences
Fossils • relics or impressions • preserved • because the material that surrounds the organism prevents it from decaying • Mostly in sedimentary rocks • Proposed: Earth- hundreds of millions in age rather than thousand years old Fossil Record
Fossil Record • Fossils in layers of rocks • gradual change over time • Succession is compatible with other evidences of the major branches of descent in the tree of life
Cold places: animals might fell into crevasses in ice or trapped in snow fields Trapped in sticky sap of trees: amber When trapped in peat bogs (certain kind of quicksand) Fossil formation Mummy Juanita is a frozen Inca mummy of a teenage girl who died more than 500 years ago and was discovered in Peru in 1995 by anthropologist Johan Reinhard and his Peruvian climbing partner Miguel Zarate. Also known as Momia Juanita (original Spanish), the Ice Maiden, the Lady of Ampato and the Frozen Lady, this mummy is unfortunately going through quite a difficult modern life and not doing so well. In 2006 daily newspaper El Comercio published that an expert from the U.S. Smithsonian Institution who was vacationing in the southern Andean city of Arequipa detected dampness inside the mummy's glass-enclosed refrigeration compartment. Shown above: Mummy Juanita when found on Mount Ampato in Peru in 1995. Otzi the Iceman is a well-preserved natural mummy of a man from about 3300 BC, found as shown in the above astonishing photographs by two German tourists, Helmut and Erika Simonby in 1991 in a glacier of the Otztal Alps in Italy, near its border with Austria. Otzi rivals the Egyptian "Ginger" as the oldest known human mummy, and has offered an unprecedented view on the habits of Chalcolithic (Copper Age) Europeans. peat bog is a type of wetland whose soft, spongy ground is composed largely of living and decaying Sphagnum moss. Decayed, compacted moss is known as peat, which can be harvested to use for fuel or as a soil additive
Many organism die and vanish without leaving a trace • SR: only in certain bodies of water • Organisms that live on mountains and deserts* • When exposed to weathering reveals fossils • Fossil reconstruction • Radioactive dating • Potassium 40- old fossils • Carbon 14- new fossils Problems in Assembling the Puzzle
Represents the preserved collective history of the earth’s organisms Shows the change followed change on earth What fossil records tell us
Similarities in Body Structure • Homologous structures • meet differential needs but developed from the same body parts • different mature forms but developed from the same embryonic tissue • Vestigial Organs • Reduced in size or traces of homologous organs in other species • No or little function • Doesn’t affect an organism’s ability to survive and reproduce Morphology
Transformation to vestigial organs • new adaptations that make some organs unnecessary • Serves as a clue to an animal’s evolutionary ancestry
Study of organisms at an early stages of development Embryology
Shows similar genes at work • Hox genes* • Occur because of the same basic control mechanism • Although organisms are different and evolved through mutations, similarities are retained** • Same groups of embryonic cells develop in the same order and in similar patterns*** Similarities in early development
“Ontogeny recapitulates phylogeny” • Ontogeny (development of an individual organism) is a replay of the evolutionary history of species (phylogeny) • Ontogeny provides clues to phylogeny
Use of DNA and proteins to reflect the relationships among species DNA sequences divergence human vs. chimpanzee 1.2% human vs. gorilla 1.6% human vs. baboon 6.6% • DNA of all eukaryotic organism • Always has the same basic structures and replicates in the same way • RNA of various species • may act little differently but are similar in structure • from one species to the next Biochemistry
Species differ through their distribution • Islands have many species of plants and animals that are endemic but closely related to the nearest mainland. • Islands with similar environmental conditions but in different parts of the world are not populated by closely related species. Geographic Distribution of Living Species
Examples: • Darwin’s Finches • Armadillos in South America • Australia’s pouched mammals Geographic Distribution of Living Species