Transcript Darwin`s Contributions

UNIT 3: DARWIN AND MENDEL
I. Darwin’s Contributions
I. Darwin’s Contributions
A. Life
- Born Feb 12, 1809
I. Darwin’s Contributions
A. Life
- Born Feb 12, 1809
- Graduated Cambridge,
intending to join the clergy
I. Darwin’s Contributions
A. Life
- Born Feb 12, 1809
- Graduated Cambridge,
intending to join the clergy
- 1831-36, Naturalist on
H.M.S. Beagle
I. Darwin’s Contributions
A. Life
- Born Feb 12, 1809
- Graduated Cambridge,
intending to join the clergy
- 1831-36, Naturalist on
H.M.S. Beagle
- 1859: Origin of Species
I. Darwin’s Contributions
A. Life
- Born Feb 12, 1809
- Graduated Cambridge,
intending to join the clergy
- 1831-36, Naturalist on
H.M.S. Beagle
- 1859: Origin of Species
- Died April 19, 1882,
interred in Westminster Abbey
B. The Origin of Species
B. The Origin of Species
1. “One Long Argument”
- observations leading to the conclusions that:
- life changes through time
B. The Origin of Species
1. “One Long Argument”
- observations leading to the conclusions that:
- life changes through time
- species descend from shared ancestors
A
B
C
B. The Origin of Species
1. “One Long Argument” – evidence of ancestry
2. Proposed Hypothesis for HOW change occurs:
- Natural Selection
B. The Origin of Species
1. “One Long Argument” – evidence of ancestry
2. Proposed Hypothesis for HOW change occurs:
- Natural Selection
3. Dilemmas – things that didn’t “fit”
C. Observations
1. Geology
- The Earth is OLD
- James Hutton (1726-1797)
Scottish Geologist
Hadrian’s Wall, but by the
Roman Emperor Hadrian in
122 A.D.
2000 years old, but no sign
of erosion. How much older
must highly worn and eroded
granite outcrops be?
And how long must
it have taken for the
layers of sediment
comprising the
White cliffs of
Dover to
accumulate?
If rates of erosion and mountain building have been uniform,
governed by the processes we see operating in nature today,
then: "(in geology) we find no vestige of a beginning,—no
prospect of an end." …. (The Earth is immeasureably old.)
C. Observations
1. Geology
- The Earth is OLD
- Charles Lyell (1797-1875)
British Geologist
Principles of Geology
Promoted the concept of
UNIFORMITARIANISM
(slow, steady change, accumulating over long periods of
time, can result in major effects…)
C. Observations
2. Paleontology
a. Major groups appear at different times - additive
recent
Mammals
Birds
Reptiles
Amphibians
Jawed fishes
past
Jawless fishes
C. Observations
2. Paleontology
b. Within a lineage,
there are patterns of gradual
change
C. Observations
2. Paleontology
b. Within a lineage,
there are patterns of gradual
change
c. Within a lineage,
there are patterns of radiation
(many descendants from few
ancestors).
C. Observations
3. Comparative Anatomy
- Homologous Structures
C. Observations
3. Comparative Anatomy
- Homologous Structures
Same structure, but
different uses in
different environments
(correlated pattern)
C. Observations
3. Comparative Anatomy
- Analogous Structures
C. Observations
3. Comparative Anatomy
- Analogous Structures
Different structures, but
same uses in the same
environment .
(again, a correlation
between anatomy and
environment)
C. Observations
3. Comparative Anatomy
- Vestigial Structures – Whale hip bones
C. Observations
3. Comparative Anatomy- Vestigial Structures
Human structures
Argentina
C. Observations
4. Biogeography
- Community Convergence
In similar environments,
there are organisms that fill
similar ecological roles – and
they are morphologically
similar.
Correlated patterns…
Australia
C. Observations
4. Biogeography – Island Faunas
C. Observations
4. Biogeography – Island Fauna
- Fauklands – species same as mainland
- Galapagos – species different from mainland
a. degree of isolation correlated with uniqueness of
inhabitants…..
Voyage of the Beagle – Darwin (1845) "The natural history of
these islands is eminently curious, and well deserves attention.
Most of the organic productions are aboriginal creations, found
nowhere else;
Flightless Cormorant
“…there is even a difference between the inhabitants of the
different islands; yet all show a marked relationship with those
of America, though separated from that continent by an open
space of ocean, between 500 and 600 miles in width.”
Green Iguana – Central and South
America
“…The archipelago is a little world within itself, or rather a
satellite attached to America, whence it has derived a few stray
colonists, and has received the general character of its
indigenous productions. Considering the small size of the
islands, we feel the more astonished at the number of their
aboriginal beings, and at their confined range.”
Galapagos Land
Iguana, pallid
species, only on
Santa Fe island.
“… Seeing every height crowned with its crater, and the
boundaries of most of the lava streams still distinct, we are led to
believe that within a period geologically recent the unbroken
ocean was here spread out.”
“…Hence, both in space and time, we seem to be brought
somewhat near to that great fact -- that mystery of mysteries -the first appearance of new beings on this earth.”
The Voyage of the Beagle – Charles Darwin
C. Observations
4. Biogeography – Island Faunas
a. Isolation correlates with uniqueness
C. Observations
4. Biogeography – Island Faunas
a. Isolation correlates with uniqueness
b. islands are dominated by dispersive forms