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Evolution and Classification Unit 8. Earth’s History NoteS. Earth’s History. Theories Abiogenesis/spontaneous generation = Life from nonliving matter Redi’s experiment (textbook p.380) FALSE Biogenesis = Life from living matter Pasteur’s experiment (textbook p. 381) TRUE.
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Earth’s History • Theories • Abiogenesis/spontaneous generation= Life from nonliving matter • Redi’s experiment (textbook p.380) • FALSE • Biogenesis= Life from living matter • Pasteur’s experiment (textbook p. 381) • TRUE
Early History of Earth • Super hot • Colliding meteorites heating surface • Frequent volcanic eruptions (lava and gases released) • Atmosphere- No free oxygen • Atmosphere- Water vapor, carbon dioxide, nitrogen, other gases present • 4.4 bya Earth began to cool
Earth’s History • The 1st living organisms were said to be anaerobic (without oxygen) and prokaryotic (without a nucleus) and unicellular • Over time, these organisms became photosynthetic (release oxygen into atmosphere) • Then, these organisms evolved to be aerobic (with oxygen) and eukaryotic (with a nucleus) and multicellular
Endosymbiosis Theory Fig 14.15 p. 385 • Supportive Evidence: • Mitochondria and Chloroplast contain own DNA , surrounded by own plasmamembrane, and reproduce through binaryfission.
Exit Ticket • The theory that life is derived from nonliving matter is called abiogenesis or ______________ _____________. • The two scientists that disproved the theory of abiogenesis was _____________ and ______________. • (True/False) The early atmosphere had no free oxygen to support living organisms. • The early atmosphere was (hot/cold). • The 1st living organisms were said to be ________(without oxygen) and ____________(without a nucleus) and unicellular.
Endosymbiosis Theory Notebook Page ______ Front---Draw, Color, Label & Descriptions • Page 385 Figure 14.15 Back---Write questions & answers • Early Earths atmosphere was very (hot, cold) and contained no free (oxygen, nitrogen).Therefore, the very first organism were (aerobic, anaerobic). • Which types of cells appeared first? (prokaryote, eukaryote) 3. The chloroplast is the site of (cellular respiration, photosynthesis). 4. Describe the fossilization process.
History of Evolution • Charles Darwin – The “Father of Evolution” • Traveled to the Galapagos islands in 1831 • Islands off the coast of South America • Darwin studied the plants and animals of the islands
Darwin’s Finches • Darwin studied finches (a type of bird) • Finches were similar looking species except for their beaks • Each type of finch had adaptedto their diet! • Seed eaters = thick, rigid beaks • Fruit eaters = thinner, less rigid beaks • Nectar eaters = long, thin beaks
Evolution • Evolution= a gradual change over time • Occurs over many generations • Evolution can lead to the formation of a new species------speciation
Natural Selection • = nature selects the best traits for survival • Over time, the beneficialadaptationmakes up a much larger percentage of the population • Which leads to gradual change in a species over time • Also known as – Survival of the fittest
Artificial Selection • Breeding organisms with specific traits in order to produce offspring with identical traits
Exit Ticket • _________ ________the “Father of Evolution” and he travelled to the ______________ islands. • Define natural selection. • Natural selection is also called __________ ____ _____ _________. • Breeding organisms with specific traits in order to produce offspring with identical traits is called _____________ ____________. • _____________ -gradual change in a species over time.
Natural Selection • Natural Selection: Organisms that are best adapted to an environment to survive and reproduce more than others
Darwin’s Theory of Natural Selection occurs in four steps: • Overproduction • Variation • Competition • Selection
1. Overproduction • Each species produces more offspring that can survive
2. Variation • Each individual has a unique combination of inherited traits. • Adaptation:an inherited trait that increases an organism’s chances of survival
Why is Variation Important? • Because the environment changes. • The more variation within a species, the more likely it will survive • EX: If everyone is the same, they are all vulnerable to the same environmental changes or diseases • The more variation of types of speciesin an habitat, the more likely at least some will survive • EX: Dinosaurs replaced by mammals
Which community has a better chance of surviving a natural disaster? Community A Community B
3. Competition • Individuals COMPETE for limited resources: • Food, water, space, mates • Natural selection occurs through “Survival of the fittest” • Fitness: the ability to survive and reproduce • Not all individuals survive to adulthood
4. Selection • The individuals with the best traits / adaptations will survive and have the opportunity to pass on it’s traitsto offspring. • Natural selection acts on the phenotype(physical appearance), not the genotype(genetic makeup) • Ex: When a predator finds its prey, it is due to the prey’s physical characteristics, like color or slow speed, not the alleles (BB, Bb)
Descent with Modification • Descent with Modification – each living species has descended, with changes, from other species over time. • Common Descent – all living organisms are related to one another
How do we see natural selection? • Pesticide and antibiotic resistance (Textbook p. 399 Figure 15.5)
Bacterial Resistance to AntibioticsNotebook Page ______ Front---Draw, Color, Label & Descriptions • Page 399 Figure 15.5 Back---Write questions & answers • The development of bacterial resistance to antibiotics is ______________ evidence for evolution. • Define/explain Bacterial Resistance.
Exit Ticket • What are the four steps to natural selection? 1.______________ 3. ____________ 2.______________ 4. ____________ • An inherited trait that increases an organism’s chances of survival is called a(n) ___________. • Natural selection acts on the _________ (physical appearance), not the _________(genetic makeup). • ________ ____ _________ is the idea that each living species has descended, with changes, from other species over time. • Another name for Natural Selection. ______ __ __ ____.
Evidence for EvolutionNotes Charles Darwin
Individuals with traits that are not well suited to their environment either die or leave few offspring. • Evolution occurs when good traits build up in a populationover many generations and bad traits are eliminated by the death of the individuals.
Peppered Moth A • Which moth will the bird catch? B
Evidence for Evolution • Structural Adaptations • Fossils • Anatomical Evidence • Biochemical Evidence • Embryonic Structures (Embryology)
Structural Adaptations • Adaptation: process that enables an organism to respond to environmental factors and live to produce offspring • Ex: Blind mole rats (Fig 15.3 p. 396) • Mimicry: enables one species to resemble another species • Camouflage: enables species to blend with their surroundings
Fossils • Used to compare bone structures • Used to determine when an organism lived and where it lived • they can be ordered to help scientists understand which animals lived before others.
Fossils-found in sedimentary rocks • RelativeDating • A method of determining the sequential order of fossils and sediment • Younger layers on top of older layers • AbsoluteDating aka Radioactive Dating • Calculating the amount of radioactive substance left in the fossil • Ex. C-14
Anatomical Evidence • Homologous structures • Similar structure but different function • Common ancestor Example two anatomical structures in different species produced from the same embryonic tissues Arm of a Human and a Cat
Anatomical Evidence • Analogous Structures Different Structures but Similar function No common ancestor
Anatomical Evidence • Vestigial Structures = may have once had a function but have evolved to be useless over time • Examples: • Whale’s hipbone • Human appendix • Human wisdom teeth
Biochemical Evidence • Comparison of DNA, RNA and proteins (amino acids) between species Example Human insulin is more similar to chimpanzee insulin than mouse insulin
Embryology • = similarities among developing embryos
BUT what is the BEST way to determine the evolutionary relationship between species??? • Biochemical Evidence! • Comparing the amino acid sequences of their proteins • Comparing DNA
From these evidences, we can determine… • Common ancestry! = a group of organisms share common descent or a common ancestor