08 - Find someone who knows! 1. How old is the oldest...

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1 Find someone who knows! 1. How old is the oldest fossil evidence of life on Earth? What was it? Was it a prokaryote or a eukaryote? What environment do scientists think it was from? How long was Earth around without evidence of life? 2. List the 6 “kingdoms” of Life. 3. What is the difference between “evolution” and “natural selection”? Earliest fossil record of life • 3.5 billion years old – oldest rocks on Earth 3.8 billion years old • Earth not around for long without it! • microscopic filament • from Western Australia • Archae- bacteria (prokaryotic)- live in acidic hot-springs and undersea vents; using chemo-synthesis to produce energy. • found in chert- a hydrogenous mineral – hydrothermal or normal marine/lake sediment deposits • New evidence that the first sign of life on Earth occurred in deep ocean around hot vents (“Palaeotemperature trend for Precambrian life inferred from resurrected proteins”, Nature, Feb. 2008). Schopf, Science, 1993 Prokaryotes (“ before cells (1) Archea (2) Bacteria (Prokaryotes, before cells ”) Eucaryotes (“ true cells ”) (3) Protoctists (mixed-bag of single-celled organisms, marine Algae, etc.) (4) Fungi (5) Animals (6) Plants Kingdoms of Life Table 13-4, p. 375
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What is evolution? What is evolution? • Evolution is a process that results in heritable changes in a population spread over many generations – Change in the function and form of organisms – Heritable in that these changes are passed on to offspring – Changes are not seen in individuals, but within populations over time • Evolution is a process that is universally accepted by scientists and can be observed on scales from the laboratory to the fossil record What is natural selection? What is natural selection? • Natural selection is a scientifically accepted mechanism that causes evolutionary change in a population • The idea was proposed by Charles Darwin in The Origin of Species ( 1859 ) 1. Variation exists between individuals in a population 2. Individuals who vary in ‘favorable’ ways are more likely to live long and reproduce sucessfully 3. Their traits are inherited by their offspring Marine Ecology • interactions of organisms with each other and with their environment • how these interactions affect survival and reproduction • interdependency between living things in the ocean Organism • an individual living system (ex: animal, plant, fungus, or micro-organism) • prokaryotic or eukaryotic, based on cell type green algae cell bacterium cell E coli bacteria An orange Elephant Ear sponge (Agelas clathrodes) at the Florida Keys National Maritime Sanctuary. In the background is a deep water sea fan (Iciligorgia schrammi), and the giant slit- pore sea rod (Plexaurel a nutans). These soft corals are slow moving animals but are often mistaken for plants. blue crab
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This note was uploaded on 04/29/2008 for the course EAS 104 taught by Professor Brown during the Spring '08 term at Purdue University-West Lafayette.

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08 - Find someone who knows! 1. How old is the oldest...

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