c harles d arwin : t heory of e volution as a m echanistic p rocess jrmg bio1 2008
TRANSCRIPT
![Page 1: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/1.jpg)
CH
AR
LES
DA
RW
IN: T
HEO
RY
O
F E
VO
LU
TIO
N A
S A
M
EC
HA
NIS
TIC
PR
OC
ESS
JRMGBio1 2008
![Page 2: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/2.jpg)
DARWIN’S IDEA OF COMMON DESCENT
Descent with modification A.K.A
EVOLUTION
common ancestor/prototype
Accumulated diverse modifications or adaptations
![Page 3: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/3.jpg)
TH
E F
INC
HES
PO
SED
QU
ES
TIO
NS
TO
DA
RW
IN: D
ID T
HEY
D
ES
CEN
D F
RO
M O
NE M
AIN
LA
ND
AN
CES
TO
R, D
ID IS
LA
ND
S
ALLO
W IS
OLATED
PO
PU
LATIO
NS
TO
EV
OLV
E IN
DEP
EN
DEN
TLY,
AN
D C
OU
LD
PR
ES
EN
T-DAY
SP
EC
IES
HA
VE R
ES
ULT
ED
FR
OM
C
HA
NG
ES
OC
CU
RR
ING
IN E
AC
H IS
OLATED
PO
PU
LATIO
N
![Page 4: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/4.jpg)
DARWIN’S IDEA OF COMMON DESCENT
Life history is like a tree Common trunk: multiple
branching and re-branching
Common ancestor in each fork of branching
lineage of common descent
Extinct species
![Page 5: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/5.jpg)
TAXONOMY: TREE OF LIFE
Carolus Linnaeus Species are fixed Ordered the great diversity of organisms into “groups
subordinate to groups” Kingdom
Phylum Class Order
Family Genus
Species
![Page 6: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/6.jpg)
Reflected the genealogy of the tree of life
![Page 7: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/7.jpg)
![Page 8: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/8.jpg)
DARWIN’S IDEA OF MULTIPLICATION OF SPECIES species either split
into or bud off other species
geographical isolation of a founder species.
Founder effect. The frequency of the a allele is low in the initial population, but a small subset, in which one individual is Aa, is removed from the large population and founds a new population. The frequency of a is markedly higher in this new population, due to its relatively high frequency in the founders
![Page 9: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/9.jpg)
DARWIN’S IDEA OF MULTIPLICATION OF SPECIES different ecological niches provide different ways
of living different plants and animals come to fill different niches with
different shapes and behaviors.
![Page 10: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/10.jpg)
![Page 11: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/11.jpg)
DARWIN’S IDEA OF GRADUALISM
changes through the gradual change of population rather than the sudden production of new individuals
species arise: Through gradual accumulation of adaptations to a
different environment
![Page 12: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/12.jpg)
![Page 13: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/13.jpg)
E.G
. DA
RW
IN’S
FIN
CH
ES
A
DA
PTIV
E
RA
DIA
TIO
N
![Page 14: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/14.jpg)
![Page 15: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/15.jpg)
Rapid evolution may arise: Isolation of small population Migration of small group in a new environment Through mass extinction Because of geological barriers
![Page 16: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/16.jpg)
DARWIN’S IDEA OF NATURAL SELECTION Compared processes in nature with artificial selection
Developed a scientific hypothesis to explain how evolution occurs
Struggle for existence (Malthus) Members of each species compete regularly to obtain
food and living space and other necessities in life Central to his Theory of Evolution
![Page 17: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/17.jpg)
Survival of the Fittest
key factor in the struggle for existence
Fitnessability to survive and reproduceresult of adaptationcentral to the process of evolution by natural selection
![Page 18: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/18.jpg)
LOW FITNESS Either DIE or LEAVE FEW OFFSPRINGS
HIGH FITNESS LEVEL many OFFSPRINGS
referred to as: NATURAL SELECTIONaccumulation of changes that differentiate groups from one another, such that a new species may arise
![Page 19: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/19.jpg)
DARWIN’S MISSING INGREDIENT
Darwin did not understand the genetic basis for variation
variations mutations genetic recombination
mutation as a raw material for evolution
![Page 20: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/20.jpg)
OTHER THINGS TO BE CONSIDERED
Natural vs. Artificial selection
Importance of population in evolution smallest unit that can evolve Natural selection acts on individuals but INDIVIDUALS
DO NOT EVOLVE
![Page 21: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/21.jpg)
DARWINIAN VIEW OF LIFE
Diverse forms have arisenDESCENT WITH MODIFICATION FROM
ANCESTRAL SPECIES Biological diversity
Mechanism of modification NATURAL SELECTION
![Page 22: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/22.jpg)
PATTERNS OF EVOLUTION
Mass extinction 99% of the species ever lived are now extinct wiped out whole ecological systems* Cretaceous extinction
Large asteroid struck the earth Can be caused by eruptions of many large volcanoes (Permian
and Cretaceous) , changing of positions of continents and changing of sea levels
![Page 23: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/23.jpg)
PATTERNS OF EVOLUTION
Adaptive Radiation single species or small group of species has evolved
into several different forms that live in different ways Ex. Darwin’s Finches
Dinosaurs Mammals
![Page 24: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/24.jpg)
![Page 25: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/25.jpg)
PATTERNS OF EVOLUTION Convergent Evolution
unrelated organisms come to resemble one another
Natural selection may mold different body structures structures tend to function the same way and look
similar
Analogous structures same look and function Different embryonic origin
![Page 26: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/26.jpg)
![Page 27: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/27.jpg)
![Page 28: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/28.jpg)
PATTERNS OF EVOLUTION Coevolution
two species evolve in response to the changes in each other over time
Ex. Fig trees and wasps
![Page 29: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/29.jpg)
PATTERNS OF EVOLUTION
Developmental Genes and Body Plans
Hox genes
![Page 30: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/30.jpg)
PROCESS OF SPECIATION
Species group of organisms that can interbreed and produce a
fertile offspring Share a common gene pool
As new species evolve populations become reproductively isolated from each other
Reproductive isolation Can be: Behavioral, Geographical and Temporal
![Page 31: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/31.jpg)
PROCESS OF SPECIATION Behavioral isolation
Capable of interbreeeding but has different courtship rituals or behavior
Ex. Eastern and western meadowlark
Geographical isolation Two populations are separated by geographic barriers Acted by natural selection Ex. Abert and Kaibab Squirrels
![Page 32: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/32.jpg)
PROCESS OF SPECIATIONBehavioral Geographical
![Page 33: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/33.jpg)
Temporal isolation Two or more species reproduce at the different times
PROCESS OF SPECIATION
![Page 34: C HARLES D ARWIN : T HEORY OF E VOLUTION AS A M ECHANISTIC P ROCESS JRMG Bio1 2008](https://reader036.vdocuments.us/reader036/viewer/2022062511/55145425550346284e8b5284/html5/thumbnails/34.jpg)
DIANE DODD’S EXPERIMENT