Evolution

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Evolution
Lec 11 11Feb02
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The Depth of Evolutionary Time
Oldest fossils
3.7 billion years ago
microbial microfossils
Making the history of life proportionate to one
year
, each day is 10 million years long
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The Year of Life
Earths origin was Oct 15 of the previous year
Life begins, Jan 1, 12 midnight
prokaryotes
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The Year of Life
Earths origin was Oct 15 of the previous year
Life begins, Jan 1, 12 midnight
prokaryotes
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The Year of Life
Life begins, Jan 1, 12 midnight
prokaryotes
When do our kind of species evolve?
Atmosphere goes aerobic on June 19
2 billion years ago
Photosynthetic prokaryotes did it
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The Year of Life
1st Eukaryotes
Aug 18
1.4 billion years ago
1st Animals
Oct 23
700 million years ago
Start fossil record
Nov 2
600 MYA
1st Vertebrates
Nov 10
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The Year of Life
1st amphibians
27 Nov
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The Year of Life
1st amphibians
27 Nov
1st reptiles
4 Dec
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The Year of Life
1st amphibians
27 Nov
1st reptiles
4 Dec
Age of dinosaurs
- 23 Dec
8 Dec
150 million years
!
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The Year of Life
1st amphibians
27 Nov
1st reptiles
4 Dec
Age of dinosaurs
- 23 Dec
8 Dec
150 million years
!
150 million years
is a success story
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The Year of Life
the first
mammals
Dec 14
birds
Dec 16
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The Year of Life
the first
mammals
Dec 14
birds
Dec 16
flowering plants
Dec 22
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The Year of Life
the first
mammals
Dec 14
birds
Dec 16
flowering plants
Dec 22
primates
Dec 23
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The Year of Life
the first
mammals
Dec 14
birds
Dec 16
flowering plants
Dec 22
primates
Dec 23
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The Year of Life
When humans?
first hominids
Dec 31
2 pm
Neanderthals
Dec 31
1145 pm
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The Year of Life
first hominids
Dec 31
2 pm
Neanderthals
Dec 31
1145 pm
Homo sapiens
Dec 31
1154 pm
last ice age
Dec 31
1158 pm
Human history
Last 70 seconds
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Natural selection
How evolve adaptations ?
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Darwin on the Galapagos
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Galapagos Islands
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Galapagos Islands
transmutation of species
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(1) Individuals vary
Natural selection
genetic diversity
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(2) Overproduction of progeny
biotic potential
N
logistics curve
t
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(2) Overproduction of progeny
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(2) Overproduction of progeny
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only a few survive
(2) Overproduction of progeny
biotic potential
N
logistics curve
lost
t

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(3) Competition between individuals
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(4) Fittest individuals survive
and reproduce
Thus, population becomes better adapted
e.g. a population of bacteria
now add antibiotic
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(4) Fittest individuals survive
and reproduce
Thus, population becomes better adapted
e.g. a population of bacteria
now add antibiotic
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(4) Fittest individuals survive
and reproduce
Thus, population becomes better adapted
e.g. a population of bacteria
now add antibiotic
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(4) Fittest individuals survive
and reproduce
Thus, population becomes better adapted
e.g. a population of bacteria
now add antibiotic
and they reproduce
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a routine mutant hunt ..
agar penicillin
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a routine mutant hunt ..
agar penicillin
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Antibiotic resistance in disease bacteria