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History of Life and the Origin of Species. Mrs. Stewart Honors biology Central Magnet School. Standards:. CCSS ELA 9-10.2 I can trace the historical development of the theory of evolution I can summarize the evidence for the theory of evolution CCSS ELA 9-10.8
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History of Life and the Origin of Species Mrs. Stewart Honors biology Central Magnet School
Standards: • CCSS ELA 9-10.2 • I can trace the historical development of the theory of evolution • I can summarize the evidence for the theory of evolution • CCSS ELA 9-10.8 • I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.
Objectives (today, I will…) • Differentiate between spontaneous generation and biogenesis • Differentiate between Charles Darwin and Jean-Baptiste Lamarck
Choose… • But choose wisely. • Decide which partner is the bird and which is the cat.
History of Life • Biogenesis: • All living things come from other living things • Spontaneous Generation: • Living things could arise from nonliving things
Redi’s experiment • Previous idea: Flies were created from rotten meat • Redi: Meat kept away from adult flies would not produce maggots
Spallanzani& Pasteur • Spallanzani – tried to disprove that microorganisms arose from a “vital force” in the air • Pasteur – improved spallanzani’s experiment to eliminate the flaw of “no air”
Cats • Tell your bird how Pasteur improved upon Spallanzani’s experiment to disprove spontaneous generation
Endosymbiosis • Where/how did mitochondria get their own DNA? • How did chloroplasts become so specialized? • Theory of Endosymbiosis: • Aerobic prokaryotes were engulfed by eukaryotic cells evolved into mitochondria (which perform aerobic respiration) • Photosynthetic prokaryotes were engulfed by plant cells and evolved into chloroplasts (where photosynthesis occurs)
Ch. 15.1 – 15.2History of Evolution Mrs. Stewart Honors Biology Central Magnet School
What is Evolution? • Dictionary: • The gradual development/change of something; especially from a simple to complex form. • Text book: • (In biology) Generally, the process of change by which new species develop from pre-existing species over time • Evolution of Dance
Birds • Tell your cat what Evolution means. Give an example (not one that Mrs. Stewart used)
18th Century Ideas • About living species: • About the Earth: • Uniformitarianism All species were permanent and unchanging. Earth was only a few thousand years old and unchanging. 19th Century Ideas Idea by Charles Lyell that said geologic processes happed slowly over time and that some features of the Earth may take millions of years to form.
Cats • Give your bird an example to support Lyell’s theory.
Jean-Baptiste Lamarck • French Naturalist • 1809 • Lamarck’s Hypothesis: by selective use or disuse of organs, organisms acquire or lose certain traits. These traits could then be passed on to their offspring. • Lamarck believed over time, this process led to change in a species.
Lamarck’s Hypothesis 1. Tendency toward perfection - All organisms have an innate tendency toward complexity and perfection, so they are continually changing to be more successful in their environment 2. Use and disuse - Organisms can alter their bodies/organs by use or disuse 3. Inheritance of acquired traits - Organisms can pass on those altered body parts/organs to the offspring
Birds • What did Lamarck get right?
Cats • What did Lamarck get wrong?
Lamarck the Loser • First to develop a hypothesis of evolution • First to realize organisms adapt to their environment • But, Behavior has no effect on inheritable characteristics
Ch. 15.1 – 15.2History of Evolution Mrs. Stewart Honors Biology Central Magnet School
Charles Darwin • 1809 – 1882 • Naturalist – study of nature and the natural world • Sailed on the HMS Beagle in 1831 • Every time the ship docked, Darwin went ashore to collect plant and animal specimens
Darwin’s observations piqued his interest in the diversity of life he observed. • Darwin even found evidence that suggested species once present on earth had vanished. • Researchers today speculate that 99.9% of all species that ever inhabited earth are now extinct.
Galapagos Islands • The islands were close together, but had very different climates • Smallest and lowest islands = hot, dry & barren • Hood Island = sparse vegetation • Higher islands had greater rainfall and a different assortment of plants/animals • Isabella Island = rich vegetation • Land Tortoise shell shapes could be used to identify which island it inhabited
Hood Island Tortoise Pinta Island Tortoise What predictions can YOU make about the island environment for each tortoise? What observations can YOU make about these species of land tortoise? Isabella Island Tortoise
Hood Island Tortoise Pinta Island Tortoise Which island would you predict has only low-lying vegetation? Isabella Island Tortoise
Darwin’s Idea • Darwin observed that the plants and animals varied noticeably among the different Galapagos Islands. • However, Darwin wondered if animals living on different islands had once been members of the same species– originating from the same South American ancestor
Darwin’s Finches • Darwin observed many different types of “finch” and noticed several different beak shapes. • Why? • He began to notice different shaped beaks were “adaptations” for different food sources
Religion’s Role • Darwin was a devout Catholic • He knew that his ideas, based on what he observed would provoke the catholic church • He debated over what to do for 25 years.
Darwin’s Theory –Descent With Modification The Origin of Species by Means of Natural Selection – 1858 • Every species – living or extinct – descended by reproduction from preexisting species • AND • Species must be able to change over time
Natural Selection Mrs. Stewart Honors biology Central Magnet School
Review What was Lamarck’s hypothesis? What did Darwin believe? Inheritance of acquired traits Species changed as environment changed – adaptation and survival of the fittest
Standards: • CCSS ELA 9-10.2 • I can trace the historical development of the theory of evolution • I can summarize the evidence for the theory of evolution • CCSS ELA 9-10.8 • I can critique and evaluate competing evolutionary arguments based on scientific knowledge, empirical evidence and logical arguments regarding relevant factors.
Objective (Today I will…) • Explain the idea of “natural selection” and determine “fittest” • Examine how adaptations help animals survive better
Darwin’s reasoning for Natural Selection • Overproduction – more offspring are produced than can survive due to competition for resources • Genetic Variation – within a population, individuals have different traits. New traits may appear spontaneously. • Struggle to survive – constant competition may cause some variations/traits to be advantageous • Differential Reproduction – Organisms with the best adaptations will survive and reproduce, thus the advantageous adaptations will become most prevalent in the population.
Evolution by Natural Selection • Struggle for existence – each member of a species competes regularly for food, living space and other necessities of life. • main needs: Food, water, living space and ability to reproduce • Who wins?
Think – Pair – Share • How can we describe Natural Selection in just 4 words?
Survival of the Fittest • How well suited an organism is to it’s environment • Does fittest mean strongest? • Does fittest mean in the best shape? • Fitness – the ability of an individual to survive and reproduce • The result of adaptations
What determines fitness? • The Environment!
Fitness leads to evolution • Peppered Moth evolution
Survival of the Fittest • Fittest – the individuals most capable to survive and reproduce for multiple generations • The traits selected as the most useful for survival and reproduction are determined by the organisms environment • Natural Selection accounts for Descent with Modification as species become better adapted to different environments.
Birds • Explain to your cat how the environment can determine fitness – use a specific plant or animal as an example. (Not one Mrs. Stewart gave you)
What is a Population? • A group of organisms of the same species, that live in the same area, AND that interbreed
Adaptation vs. Acclimatization • Adaptation - Changes in traits in populations over time • Example: White moth population becoming a black moth population after 5 generations. • Acclimatization – individual organism changes physiologically • Example: growing thicker fur in winter
Adaptations • Any inherited characteristic that increases an organism’s (and therefore, a populations) ability to survive and reproduce • Anatomical or structural characteristics • Porcupine quills - protection • Longer necks in giraffes – find food • Physiological processes • How a plant performs photosynthesis • Instinctual Behaviors • Hunting in packs • Living in burrows
Can You… • Differentiate between biogenesis and spontaneous generation • Differentiate between Charles Darwin and Jean-Baptiste Lamarck • Explain the idea of “natural selection” and determine “fittest”
Evidence of Evolution Mrs. Stewart Honors Biology Central Magnet School