BIOL1006 Lecture 4: Lecture 4 part 1
9 Jun 2018
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Lecture 4
Learning Objectives
• Be able to discuss major epochs in Earth’s history
• Know how many major extinctions there are
• Be able to discuss hypotheses for the origins of life
• Be able to discuss the three basic functions needed for life
• Understand how continental movements have shaped life in earth
• Know what the Wallace line is able be able to explain why it occurs
Formation of the Earth
• Big Bang occurred 13.75 billion years ago
• Earth formed 4.54 billion years ago
• Oldest rocks are about 4 billion years old
• First evidence of cellular like 3.5 billion years ago
Hadean Earth
• Volcanic activity
• Eruptions
• Everything on fire
What are the most basic functions needed to make a life form
• Energy, metabolism
• Heredity
• Compartmentalisation
• Response to stimuli
• Cellular memory
• Respiration
• Photosynthesis
• Reproduction
Hypotheses for the Origin of Life
• Abiogenesis: the original evolution of life or living organsims from
inorganic or inanimate substances
• Panspermia/Exogenesis: the hypothesis that lide originated elsewhere
in the universe and came to earth via meteoroids, asteroids, comets, etc.
Knowing the origin of life is not a precondition for evolution
How do we know about the history of life?
• Our understanding of out planet’s biological past comes mostly from the
fossil record
• Fossils are the preserved remains of organisms
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 4: be able to discuss major epochs in earth"s history. Formation of the earth: big bang occurred 13. 75 billion years ago, earth formed 4. 54 billion years ago, oldest rocks are about 4 billion years old, first evidence of cellular like 3. 5 billion years ago. Hadean earth: volcanic activity, eruptions, everything on fire. What are the most basic functions needed to make a life form: energy, metabolism, heredity, compartmentalisation, response to stimuli, cellular memory, respiration, photosynthesis, reproduction. Knowing the origin of life is not a precondition for evolution. How do we know about the history of life: our understanding of out planet"s biological past comes mostly from the, fossils are the preserved remains of organisms fossil record. Fossils: fossils come in many forms of. Dating rocks: radioactive isotopes used to measure geological ages (radiometric dating, based on the time required for half of the atoms to decay, magnetic reversals.
