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Uncover the process of evolution through time, from fossils to comparative studies like embryology and biochemistry. Learn about theories from Lamarck to Darwin, understanding natural selection and adaptations. Discover how new species develop through geographic isolation, leading to adaptive radiation and speciation. Explore the gradual change of life forms over time and the sudden shifts depicted by punctuated equilibrium. Dive into the origin of life with the primordial soup theory and the formation of organic molecules. Unravel the journey from simple bacteria to complex life forms, reflecting on the Miller and Urey experiments.
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EVOLUTION • The process of change through time. • Evidences of Evolution • Fossils-the remains of a once living organism • Types of fossilization: • Petrification • Imprint • Tar/Ice/Amber
FOSSILS • Fossils always form in sedimentary rock with the older organisms in the deeper layers.
COMPARATIVE STUDIES • Evidence for evolution is also found by comparing: • Embryology • Biochemistry • Cytology • Anatomy
COMPARATIVE EMBRYOLOGY • Animals go through similar stages of embryological development. • This may show that they are related and may share common ancestry
COMPARATIVE BIOCHEMISTRY • Organisms have similar chemicals, which may show common ancestry. • Ex. • Hormones are similar in many species. • Everything contains DNA. • Similar protein structure and construction. • Use ATP • ….
COMPARATIVE CYTOLOGY • The study of cells is CYTOLOGY. • All living things are made of cells, therefore, they may share a common ancestor.
COMPARATIVE ANATOMY • Comparing the structures of different animals to find similarities. • Homologous Structures • Analogous Structures • Vestigial Structures
HOMOLOGOUS STRUCTURES • Structures having a similar origin, but are adapted for different purposes. • Ex. Human arm and whale flipper • Same structure-Different function
ANALOGOUS STRUCTURES • Structures are different but have the same basic function. • Ex. Bee wing and Bird wing • Different structure-Same function
VESTIGIAL STRUCTURES • Structures that presently have no known function, but may once have been needed. • Ex. Tonsils, appendix, whale, snake
THEORIES OF EVOLUTION • Jean-Baptiste Lamarck (early 1800’s) • Theory of use and disuse • He said that characteristics which are acquired are inherited. • Ex. Giraffes & Human Muscles
THEORIES OF EVOLUTION • August Weismann (late 1800’s) • Disproved Lamarck’s theory • He said that acquired characteristics are NOT inherited. • Studied mice
THEORIES OF EVOLUTION • Hugo de Vries (late 1800’s) • One of the first geneticists • Developed mutation theory • Said mutations are a result of genes segregating, then recombining
THEORIES OF EVOLUTION • Charles Darwin • “Father of Evolution” • Observed variation in species on the Galapagos Islands • Famous for his study of finches, among others.
DARWIN’S THEORIES • Natural Selection • Organisms with favorable adaptations tend to survive and reproduce. • The 4 principles of Natural Selection: • 1. Overproduction-populations overproduce • 2. Competition-struggle for existence • 3. Variation-leads to new generations that are better adapted to environment • 4. Survival of the Fittest - the ones best adapted, survive.
VARIATION • A bell curve shows variation within a population.
GEOGRAPHIC ISOLATION • Species that are separated from one another by natural barriers (mountains, ocean, desert) can cause new species to develop. • Ex. Emu, Ostrich, Rhea
SPECIATION • Speciation • Over time, new species will develop due to their isolation. • Ex. Emu and Ostrich cannot interbreed
ADAPTATIONS • An adaptation is a characteristic of an organism that helps it to function in it’s environment.
ADAPTIVE RADIATION • The process by which a single species evolves into several different forms that live in different ways. • Causes diversity amongst the group of organisms.
GRADUALISM • Slow steady change over time (gradually)
PUNCTUATED EQUILIBRIUM • Stable population makes a sudden and rapid change into something new.
ORIGIN OF LIFE • In the beginning… • ______________, which happened about _____________ years ago. • Then… • Molten earth cooled, forming a ___________. • Then… • Volcanoes erupted, spewing gases, forming the ____________.
ORIGIN OF LIFE • The first gases in the primitive environment were: • NH4- Methane • CO2-Carbon Dioxide • NH3-Ammonia • H2S-Hydrogen Sulfide • These gases combined to form primordial soup
ORIGIN OF LIFE • Early Earth was being bombarded by lightning and comets. • Lightning caused molecules in the primordial soup to reassemble into CHON. • Therefore, an organic molecule is born!
ORIGIN OF LIFE • Simple organic molecules began to combine to form more complex molecules. • Ex. Simple proteins, carbohydrates, lipids and nucleic acids. • This occurred around 3 billion years ago.
ORIGIN OF LIFE • Simple archaebacteria are formed about 2.5 billion years ago. • Archaebacteria evolved and adapted to the environment, forming simple monera, which then evolved into____________, which then evolved into____________.
Miller and Urey Experiment • In the 1950’s, the scientists conducted an experiment to re create the formation of life.