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Questions and Answers
What is the approximate age of the first fossil record of life, which was a prokaryote?
What is the approximate age of the first fossil record of life, which was a prokaryote?
Which event is associated with the Cambrian explosion?
Which event is associated with the Cambrian explosion?
What evolutionary force involves natural selection controlling allometric growth in genes?
What evolutionary force involves natural selection controlling allometric growth in genes?
What classification group consists of pioneers of life, occupies all ecological niches, and has an estimated existing species between 4 x 10^3 and 4 x 10^6?
What classification group consists of pioneers of life, occupies all ecological niches, and has an estimated existing species between 4 x 10^3 and 4 x 10^6?
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Which of the following hominids evolved into the first true human with a very large brain of around 1,000 cm^3?
Which of the following hominids evolved into the first true human with a very large brain of around 1,000 cm^3?
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Which theory proposes that the first passage of genetic information occurred through short RNA strands or autocatalyst like ribozyme?
Which theory proposes that the first passage of genetic information occurred through short RNA strands or autocatalyst like ribozyme?
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What process requires the presence of appropriate substrates for polymerization to occur, according to the text?
What process requires the presence of appropriate substrates for polymerization to occur, according to the text?
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At what temperature range does the text suggest life exists, from the lowest to the highest?
At what temperature range does the text suggest life exists, from the lowest to the highest?
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What condition was NOT present in Earth's early atmosphere, making it highly reductive?
What condition was NOT present in Earth's early atmosphere, making it highly reductive?
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What event is believed to have led to the generation of organic compounds on early Earth due to its impact on the planet?
What event is believed to have led to the generation of organic compounds on early Earth due to its impact on the planet?
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Study Notes
Origin of Life and the Universe
- The universe is approximately 13 billion years old, according to the Big Bang Theory and Doppler Shift.
- Earth is approximately 4.5 billion years old, formed through the cooling of the crust and solidification.
Earliest Record of Life
- The earliest recorded life form is from 3.5 billion years ago.
- The first human, Australopithecus, emerged around 0.005 billion years ago, with fossils discovered around 0.0000000002 billion years old.
Physical Conditions of Early Earth
- The temperature range on early Earth allowed for the existence of liquid water and non-brittle carbon compounds.
- The planet's size retained an atmosphere, which lacked oxygen, making it highly reductive.
- High-energy bombardment from the sun generated organics.
Evolution of Life
- Theories of life's origin include creationism, extraterrestrial origin/Panspermia, and spontaneous origin.
- Spontaneous origin theories involve abiotic synthesis, aggregation of proteins into abiotic membrane structures, and polymerization.
Biological Timescales
- Biological events are marked by geological timescales, with key events including mass extinctions and diversifications.
- The first fossil record of life dates back to 3.5 billion years ago, during the Precambrian era.
- The earliest eukaryote emerged around 1.5 billion years ago, through endosymbiosis.
Earth - The Early Years
- Late Precambrian saw the emergence of the first eukaryotic, multicellular life.
- The Cambrian explosion occurred between the Precambrian and Cambrian eras, with rapid adaptive radiation and diversification of marine life.
- The mid-Cambrian period saw the evolution of existing animal phyla.
Forces Behind Macroevolution
- Biological forces, such as natural selection, control allometric growth.
- Physical forces, such as plate tectonics, form and split supercontinents.
Study of Evolutionary History - Phylogeny
- Modern Darwinian theory involves adaptive radiation from a common ancestor.
- The concept of phylogeny is supported through studies of homology.
- Linnaeus' traditional classification systems are based on homology (parallel/divergent evolution) and analogy (convergent evolution).
The Kingdom System
- Campbell's classification scheme includes:
- Monera (pioneer organisms, 3.5 billion years old)
- Protista
- Plantae
- Fungi
- Animalia
Earth: The Middle Years
- The Permian extinction was the first major extinction at the end of the Paleozoic era, caused by tectonic plate collision.
- The Mesozoic era consisted of three periods: Triassic, Jurassic, and Cretaceous.
- The Cretaceous extinction was the second mass extinction.
The Evolution of Man
- Hominoids include placental mammals, apes (gibbons, orangutans, gorillas, chimpanzees), and humans.
- The divergence of Gorilla and Pan from Homo Sapiens occurred around 8 and 6 million years ago, respectively.
- Hominids include:
- Ardipithecus (earliest hominids, diverged 5 million years ago, bipedal)
- Australopithecus (most fossil specimens of early hominids)
- Homo (first humans, larger brain, evolving 2 million years ago)
- H.habilis (first tool users, "handy man", short person, long arms)
- H.rudolfensis (larger brain, coexisted with H.habilis)
- H.erectus (first true human, very large brain, NOT direct ancestor of modern humans)
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Description
Explore the timeline of the origin of life on Earth, from the age of the universe to the first human species. Learn about the physical conditions of early Earth that were conducive to life, such as the correct temperature range and atmosphere composition.
