Transcript Chapter 10 Principle of Evolution

Principles of Evolution
Chapter 10
Evolution
Process of biological change by
which descendants come to
differ from their ancestors
A gradual change in species over generations
in response to changes in the environment
Darwin’s theory was a result of many years of study,
and required the expertise of many scientists
to further explain observations
he made during his mid twenties
Naturalists who’s thinking set the stage for
the development of Charles Darwin’s theory
Erasmus Darwin
Charles grandfather,
doctor and poet
published in 1796
– all living things were
descended from a
common ancestor
– that complex life rose
from simple life.
“A fool you know, is a man who never tried an experiment in his life”
Jean Baptiste Lamarck
 In 1809 he published
Philosophie Zoologique
 A 'tendency to perfection',
an innate quality of nature that
organisms constantly
'improved' by successive
generation
 Inheritance of acquired traits,
physical changes could be
inherited and driven by
environmental change
Theory of Inheritance of Acquired Traits
Modifications acquired during one’s
lifetime are inherited by the next
generation
implies that the organism itself can control
the direction of change
Lamarck also believed species never went
extinct, although they may change into
newer forms
How Geology set the stage
Catastrophism
Catastrophic
events were
responsible for
mass extinctions
Gradualism
Change is a result of small steps
over long periods of time
Charles Lyell
Principles of Geology
 Uniformitarianism: processes that alter the
Earth are uniform through long periods of time
 The processes are still at work today
 This theory expanded upon gradualism and
eventually replaced catastrophism as the
favored geological theory yell
 Lyell met with Charles Darwin frequently to
discuss Darwin’s theory
“On the Origins of Species”
Alfred Wallace (1823-1913)
English Naturalist
Studied the Amazon
Rainforest
Wrote several letters
to Darwin
Came about with the
same theory at about
the same time
Thomas Malthus
British economist 1766-1834
Food, water, and shelter
are natural limits to
population growth.
population left unchecked
will outstrip man's ability to
live on this planet
The Theory of Evolution by
means of Natural Selection
Charles Darwin (1809-1882)
English Naturalist
HMS Beagle age 22
ship's naturalist
5 year voyage 1831-1836
Published the book
“Origin of Species”
in 1859
The Voyage of
the HMS Beagle
The Theory of Natural Selection
 Variations are based on natural selection
 Overproduction leads to competition
 Adaptation- certain variations can allow
an organism to survive better
“Survival of the Fittest”
 Natural selection acts on phenotype
“Nothing in biology makes sense,
except in the light of evolution”
Theodosius Dobzhansky geneticist
Natural Selection
in Action
The Peppered Moth
Evidence of Evolution
I.
The fossil recordepisodic speciation, mass extinction
II.
Geographical distribution of species
III.
Embryology- compare embryo development to
determine lineage
IV.
Anatomical Evidence
I.
Homologous Structures-
II.
Analogous Structures
III.
Vestigial Organ- serves no useful purpose
How a
fossil
forms
Mass
extinction
25-70%
of species
wiped out
5
4
3
Generally
followed
by a
period of
adaptive
radiation
2
1
Biogeography
The geographical distribution of living things
Plant
Biogeography
Animal
Biogeography
Comparative Embryology
Similar in structure but
appear different and have
different functions
Shared common ancestor
Homologous & Analogous
Body structures
Perform similar
function but not
common ancestor
Vestigial Structures
remnant of early ancestor
Comparative DNA analysis