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Tuesday 3/17/15. AIM: How are species related? DO NOW: Why do scientists develop theories? Are theories facts? Why or why not? HOMEWORK: Text read pages 375-377.Reading check pages 375 and 377. Theory. An explanation to a natural phenomena
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Tuesday 3/17/15 • AIM: How are species related? • DO NOW: Why do scientists develop theories? Are theories facts? Why or why not? • HOMEWORK: Text read pages 375-377.Reading check pages 375 and 377
Theory • An explanation to a natural phenomena • After a hypothesis is tested and yields the same results theories are developed • Theories change if scientific results change • Ex: abiogenesis: life just appears randomly • NOT TRUE
Louis Pasteur • Pasteurization: boils liquids to kill microbes • He found microscopic organisms live in the air and water surrounding us
1920’s Alexander Oparin and John Haldane: postulated conditions of early earth
Theory of primordial Soup • Hypothesized the early conditions of earth • Boiling oceans, volcanic eruptions, lightning storms • Atmospheric gases methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O). • Energy sources electric current through lightning storms and sun’s UV light • Early earth’s conditions interacted to form amino acids and small nucleic acids
Tuesday 5/5/14 • AIM: How were the first cells developed? • DO NOW: What were the conditions of early earth? Could you survive in them? • HW: Textbook read pages 380-381. RC page381
Miller and Urey • Actually created a closed system simulating early earth conditions • Observed small simple organic compounds were formed • Amino acids • Nucleic • Supports primordial soup hypothesis
From amino acids to the protocell • Amino acids combines to form proteins • Proteins evolved into RNA • RNA into DNA • Somehow cell membranes were synthesized it is still unclear how
How did the first types of cells develop? • Small organic compounds combine to create some types of membrane surrounding molecules and nucleic acid • This was called a protocell
Wednesday 3/18/15 • AIM: What is the scientific explanation for the origin of life? • DO NOW: In your own words explain the scientific explanation of the origin of life by primordial soup. • HOMEWORK: Text read pages 375-377. Answer the reading check questions on pages 375 and 377
First cells • Prokaryotes: no nucleus • Most likely archaebacteria
How then did we go from single celled prokaryotes to eukaryotes?
Lynn Margulus: endosymbiont theory • 1960’s explains how eukaryotic cells arose • Eukaryotic cells evolved from symbiotic relationships with prokaryotic cells • Evidence is seen in the DNA of both chloroplasts and mitochondria of eukaryotes which has more similarities to prokaryotic DNA and not eukaryotic
Alternative theory of origin of life: Deep sea vents • Life originated in the hydrothermal volcanic vents in the deep sea • Chemosynthesis: used the digestion of living things to make food • Photosynthesis uses light To make food • Chemosynthesis uses digested molecules to make food
Assessment • In your own words explain the scientific explanation of the origin of life by primordial soup
AIM: What are some pieces of evidence for evolution? • DO NOW: In your own words explain the scientific explanation of the origin of life. • Homework: Textbook Read pages 423-426 questions 3 and 4 pg 430
Organic Evolution • The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother. • Biological evolution, simply put, is descent with modification. • Small-scale evolution (changes in gene frequency in a population from one generation to the next) • Basically offspring displays different traits than parents • Large-scale evolution (the descent of different species from a common ancestor over many generations).
Organic evolution • Looks at the mechanism of change • How does change happen
Thursday 3/19/15 • AIM: How do scientists determine common ancestry? • Do NOW: What is descent with modification? • HOMEWORK: text read 380-381. reading check on page 381
Darwin’s descent with modification • Each generation shows a slight variation from the prior • Successful variations remain in the gene pool • Unsuccessful variations are removed
Organic Evolution • Changes in the genetic characteristics of a population over generations b) Genetic changes alter: proteins produced by organism • Changes in proteins affect the physical trait
species • A group of organsims capable of mating and producing fertile offspring
Family Tree Diagrams • used to show probable evolutionary relationships • some interpretations • multiple species can evolve from a single ancestor • many species have become extinct
Evolution • Change over time • Natural selection vs Artificial Selection • Natural selection: environmental conditions are the selecting agents • Artificial selection: humans are the selecting agents
Theory of evolution by Natural selection • Nature chooses the physical trait best fit for survival
Evidence for Evolution • Fossils Evidence of a living thing show structural changes (skip to slide 48) II. Comparative Sciences • result from common ancestry • the greater the similarity, the closer the evolutionary relationship and the more recent the common ancestor • III. The geological record • IV. Biogeography (Pangea)
Fossil Formation: law of superposition • The relative age of a fossil is determined by the layer of rock it is found in • Lower layers are older than top layers • Older. Simple organisms(lower layers) are common ancestors to more complex (upper layers)
Comparative Studies looks for Similarities Between Species 1. Cytology 2. Anatomy (structure) 3. Development embryology 4. Biochemistry
Friday 3/20/15 • AIM: what are some pieces of evidence to change over time? • DO NOW: explain how the fossil record can help determine common ancestry • Comparing fossils in the same layer as well as to prior layers allows us to determine relatedness
Cytology • cells with similar organelles appear in virtually all species • similarities in cell structure suggest that all organisms may have evolved from a single ancestor
Comparative anatomy • Compares the physical structures of organisms within different species • Homologous structures • Analogous Structures • Vestigial
Tuesday 3/24/15 • AIM: How can we determine common ancestry by analyzing physical structures? • DO NOW: Choice 1: List and describe the different branches of comparative sciences • CHOICE 2: 1- Comparative __________ analyzes the developing embryos of different species. • 2- _____________ structures are similar in both structure and function. • 3- Comparative biochemistry studies ________. • HOMEWORK: Evidence of evolution analysis questions
Pair and share • 1- Which comparative study analyzes homologous and analogous strutures? • 2- What information can we get through the analysis of homologous and analogous structures?
Comparative anatomy • Compares the anatomical structures of different species to try and determine a common ancestor
Homologous Structures • structures in different species that are truly similar and develop in the same way • ex: vertebrate forelimbs • result from common ancestry d) may now be used for different purposes
Analogous structures • Similar in function but not structure • Gives evolutionary information about the natural environment the organisms were exposed to • Does not give common ancestry • Ex: wing of butterfly (chitin) • Wing of bat (bones)
Vestigial Structures (Vestiges) • useless structures “left over” from ancestors • ex: snakes have small leg bones inherited from their lizard ancestors c) human vestiges include: • appendix • coccyx (tail bones) • tonsils
Comparative Embryology • different species go through similar stages of early development Studies the embryological development of organisms