Evolution
Origins of Origin
® Universe started = 13.7 bil years ago = Big Bang = current theory = universe’s origin
® Earth = 4550 mil years old = 4.6 bil
® Earth’s crust = layers = laid down = water/volcanic activity
↳ each layer = different age = oldest @ bottom
® Fossil dating = relative dating + radiometric dating = age of rock layer = fossil age
® At least 5 mass extinctions = species = extinct
↳ 250 mil years ago = 90% life disappeared
↳ 65 mil years ago = dinosaurs disappeared
® Studying fossils = appearance + extinction = organisms (species/groups)
= understand = change of life forms = more similar = present
= evidence = support idea = species change
® SA = rich in fossils
↳ earliest organisms (3.5 bil years ago) = stromatolites
↳ primitive land plants
↳ coelacanth
↳ mammal-like reptiles
↳ humans earliest direct ancestors
Origin of an idea about origins
Development of the theory of evolution:
Evolution:
® Gradual change/ development of something
® Used = social/ economic structures + general use
Biological evolution:
® Change in gene pool of a population
® Caused by = mutation/ natural selection: genetic drift
® = descent with modification = microevolution + macroevolution
↳ Microevolution = evolution within a species
↳ Macroevolution = descent of diff. Species from common ancestor over many
generations
® Evolution = helps understand history of life
Importance of biological evolution:
® Unifying concept = foundation = understand all biology
® Supports + explains = aspects of everyday life
® Challenges people = think for themselves
How did life originate? Single origin of life
® Current theory = was a single origin of life
® All life shares = genetic code + similar basic enzymes
Before 1700:
® Scientists accepted = species = un-relatable + ≠ change
, ↳ = fixed = created by divine power
® Scientists accepted = earth = young + static
1700 – early 1800
® Erasmus Darwin (Charles’ grandfather)
® Jean-Baptiste Lamarck
® Species gradually change over time
® Earth = millions years ≠ 1000s
Erasmus Darwin
® 1731-1802
® Country doctor
® Scientist
® Philosopher
® Inventor
® Poet
® Author
® Book = Zoonomia
® Life on earth = descended = 1 common ancestor
® Species= must have changed/evolved over time
® BUT gave ≠ mechanism for ‘transformation’
Jean-Baptiste Lamarck
® 1774-1829
® French naturalist
® Book = Philosophie Zoologique
® Species ≠ fixed
® Living species = diff to fossil types = life forms must have changed
® Domestication + selective breeding = animals/plants = change
® Cross breeding plant species = new characters
His hypotheses:
® Change = natural phenomenon ≠ divine intervention
® Organisms = change to survive in environment
® Change = passes on
® Use and disuse of body parts
↳ if environment = change = organism = change = adapt
↳ more organs = used = size increased + more efficient
↳ organs ≠ used = become smaller + disappear
® Inheritance of acquired characteristics
↳ physical/phenotypic changes/ acquired characteristics = parents to
offspring
↳ = populations change = new species formed
® eg. Giraffes long necks
Lamarck’s mechanism for evolution:
® Belief = environment = produce phenotypic changes = correct
® Incorrect = phenotypic changes = evolutionary change
® Acquired characteristic ≠ passed to offspring
, Sum up:
® Species = common ancestor
® Evolution occurred = species adapt to environment
Early 1800 - early 1900
Charles Darwin
® 1809-1882
® 5 year expedition to Southern Hemisphere = HMS Beagle
® Info on geology, biogeography + fossils
® Immense diversity among organisms
↳ both living + extinct
® Variation of individuals
↳ of same species
↳ species ≠ unchangeable
® Often puzzling distribution
↳ of different species
® Earth = extremely old
↳ allowed time = species = evolve = seen from fossils
® Great geological change = occurred
↳ different areas/land masses = isolated
® Isolation leads to species changing
® Theory on how evolution happened
® Book = The Origin of Species
Darwin’s hypotheses:
® Modification with descent
↳ diversity of species = result of evolution
↳ species = gradually modified from ancient ancestors
® Natural selection
↳ mechanism causing evolution
↳ how evolution takes place
↳ individuals bests adapted to the environment = leave most offspring
Darwin’s explanation of modification with descent:
® All related organisms = descended = common ancestor
® Ancestral species = spread = variety = new habitats
↳ adaptation to new local conditions
↳ modified + diversified = new species
® Diversification = by branching
↳ ancestral species = give rise = 2/more new related species = in new habitat
® origin species = died out
Alfred Russel Wallace:
® 1823-1913
® British naturalist/collector of wildlife specimens/author
® Accepted concept of evolution
® Fieldwork = Malay Archipelago
® North-western organisms = more similar to Asian mainland
® South-eastern organisms = more similar to Australian mainland
® Ancestors of modern species = isolated by water = evolved differently
® What caused the descendants of ancestral species to change into modern forms?
Origins of Origin
® Universe started = 13.7 bil years ago = Big Bang = current theory = universe’s origin
® Earth = 4550 mil years old = 4.6 bil
® Earth’s crust = layers = laid down = water/volcanic activity
↳ each layer = different age = oldest @ bottom
® Fossil dating = relative dating + radiometric dating = age of rock layer = fossil age
® At least 5 mass extinctions = species = extinct
↳ 250 mil years ago = 90% life disappeared
↳ 65 mil years ago = dinosaurs disappeared
® Studying fossils = appearance + extinction = organisms (species/groups)
= understand = change of life forms = more similar = present
= evidence = support idea = species change
® SA = rich in fossils
↳ earliest organisms (3.5 bil years ago) = stromatolites
↳ primitive land plants
↳ coelacanth
↳ mammal-like reptiles
↳ humans earliest direct ancestors
Origin of an idea about origins
Development of the theory of evolution:
Evolution:
® Gradual change/ development of something
® Used = social/ economic structures + general use
Biological evolution:
® Change in gene pool of a population
® Caused by = mutation/ natural selection: genetic drift
® = descent with modification = microevolution + macroevolution
↳ Microevolution = evolution within a species
↳ Macroevolution = descent of diff. Species from common ancestor over many
generations
® Evolution = helps understand history of life
Importance of biological evolution:
® Unifying concept = foundation = understand all biology
® Supports + explains = aspects of everyday life
® Challenges people = think for themselves
How did life originate? Single origin of life
® Current theory = was a single origin of life
® All life shares = genetic code + similar basic enzymes
Before 1700:
® Scientists accepted = species = un-relatable + ≠ change
, ↳ = fixed = created by divine power
® Scientists accepted = earth = young + static
1700 – early 1800
® Erasmus Darwin (Charles’ grandfather)
® Jean-Baptiste Lamarck
® Species gradually change over time
® Earth = millions years ≠ 1000s
Erasmus Darwin
® 1731-1802
® Country doctor
® Scientist
® Philosopher
® Inventor
® Poet
® Author
® Book = Zoonomia
® Life on earth = descended = 1 common ancestor
® Species= must have changed/evolved over time
® BUT gave ≠ mechanism for ‘transformation’
Jean-Baptiste Lamarck
® 1774-1829
® French naturalist
® Book = Philosophie Zoologique
® Species ≠ fixed
® Living species = diff to fossil types = life forms must have changed
® Domestication + selective breeding = animals/plants = change
® Cross breeding plant species = new characters
His hypotheses:
® Change = natural phenomenon ≠ divine intervention
® Organisms = change to survive in environment
® Change = passes on
® Use and disuse of body parts
↳ if environment = change = organism = change = adapt
↳ more organs = used = size increased + more efficient
↳ organs ≠ used = become smaller + disappear
® Inheritance of acquired characteristics
↳ physical/phenotypic changes/ acquired characteristics = parents to
offspring
↳ = populations change = new species formed
® eg. Giraffes long necks
Lamarck’s mechanism for evolution:
® Belief = environment = produce phenotypic changes = correct
® Incorrect = phenotypic changes = evolutionary change
® Acquired characteristic ≠ passed to offspring
, Sum up:
® Species = common ancestor
® Evolution occurred = species adapt to environment
Early 1800 - early 1900
Charles Darwin
® 1809-1882
® 5 year expedition to Southern Hemisphere = HMS Beagle
® Info on geology, biogeography + fossils
® Immense diversity among organisms
↳ both living + extinct
® Variation of individuals
↳ of same species
↳ species ≠ unchangeable
® Often puzzling distribution
↳ of different species
® Earth = extremely old
↳ allowed time = species = evolve = seen from fossils
® Great geological change = occurred
↳ different areas/land masses = isolated
® Isolation leads to species changing
® Theory on how evolution happened
® Book = The Origin of Species
Darwin’s hypotheses:
® Modification with descent
↳ diversity of species = result of evolution
↳ species = gradually modified from ancient ancestors
® Natural selection
↳ mechanism causing evolution
↳ how evolution takes place
↳ individuals bests adapted to the environment = leave most offspring
Darwin’s explanation of modification with descent:
® All related organisms = descended = common ancestor
® Ancestral species = spread = variety = new habitats
↳ adaptation to new local conditions
↳ modified + diversified = new species
® Diversification = by branching
↳ ancestral species = give rise = 2/more new related species = in new habitat
® origin species = died out
Alfred Russel Wallace:
® 1823-1913
® British naturalist/collector of wildlife specimens/author
® Accepted concept of evolution
® Fieldwork = Malay Archipelago
® North-western organisms = more similar to Asian mainland
® South-eastern organisms = more similar to Australian mainland
® Ancestors of modern species = isolated by water = evolved differently
® What caused the descendants of ancestral species to change into modern forms?
