1-Evolution_intro_history_July_31_s

1-Evolution_intro_history_July_31_s - 8/4/09...

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Unformatted text preview: 8/4/09 Dr.
Tamara
L
Kelly
 Office:
108A
Farquharson
 Email
contact:
 [email protected] Office
hours:
by
appointment
 Midterm:
Aug.
21st
 Final
(covers
material
from
all
3
secLons):
TBA
when
the
 Registrar’s
Office
lets
us
know…

 Email guidelines: • Include your name, student #, and the course code in the subject line. This facilitates a faster response! • Please give me at least 24 hr to respond to your email. • I do not answer email on the weekends. Announcements:
 • There
is
no
tutorial
Tuesday
Aug.
4th
 EvoluLon
 Read:
 •
Ch.
22
Descent
with
ModificaLon:
a
Darwinian
   View
of
Life
(p452‐460)
 •Ch.
23
The
EvoluLon
of
PopulaLons
(p468
‐482;
   484
–
Natural
SelecLon
can’t
Fashion
Perfect
 Organisms;
483‐484
–
PreservaLon
of
GeneLc
 VariaLon)
 1 8/4/09 Penicillin
–
the
‘wonder
drug’
 http://en.wikipedia.org/wiki/Penicillin EvoluLon
of
penicillin
resistance
 •  1942
–
brought
to
public

 •  •  IniLally
to
treat
infecLons
of
Staphylococcus
aureus
 Quickly
used
to
treat
all
sorts
of
diseases
 •  1946
–
widespread
use
 •  •  14%
of
Staphylococcus
strains
in
paLents
were
resistant
 1950
–
more
than
50%
of
all
Staphylococcus
strains
in
paLents
 were
resistant
 Many
strains
of
bacteria
develop
anLbioLc
resistance.
 How
does
this
happen?
 2 8/4/09 Global
Travel…
 •  Human
influenza
A
(H3N2)
 •  Regional
epidemics

outbreaks
worldwide
 •  EvoluLonary
stable
for
3‐8
yrs
 •  Periodic
changes
(punctuated
evoluLon)
 •  Typically
in
SE
Asia

changes
very
liile
on
trip
around
the
 world.
 Is
this
good?
 1.  Yes
 2.  No
 EvoluLon
=
the
core
of
biology
 “Nothing
in
biology
makes
sense
except
in
the
light
of
evoluLon.”
 
 
 
 
 
‐
Dobzhansky,
1973
 Physiology Medicine Behaviour Evolution Ecology Molecular Biology 3 8/4/09 The
Unity
&
Diversity
of
Life
 How
did
such
diversity
arise?
 The
Unity
&
Diversity
of
Life
 How
did
such
diversity
arise?
 4 8/4/09 Learning
Goals
for
EvoluLon
Unit
(these
may
be
 modified
slightly
at
some
point)
 •  Define/describe
the
following
terms
according
to
their
biological
definiLon:
 •  
fitness,
adaptaLon,
evoluLon,
populaLon,
natural
selecLon,
geneLc
dris,
gene
flow,
founder
 effect,
boileneck
 •  Explain
how
the
both
the
unity
and
the
diversity
of
life
can
be
explained
by
the
theory
of
evoluLon.
 •  Describe
how
natural
selecLon
acts
on
individuals
to
shape
evoluLon
in
populaLons.
 •  Explain
why
individuals
do
not
evolve
&
why
evoluLon
is
considered
a
populaLon
process.
 •  Explain
the
importance
of
geneLc
variaLon
to
evoluLon
and
natural
selecLon.
 •  IdenLfy
sources
of
variaLon.
 •  Explain
the
role
of
the
environment
in
adaptaLon.
 •  Explain
why
all
traits
are
not
adapLve.
 •  Describe
why
there
are
limits
to
adaptaLon.
 •  Explain
why
evoluLon
is
not
progressive.
 •  IdenLfy
the
scienLfic
ideas
that
influenced
Darwin.
 •  (Describe
Darwin’s
most
important
observaLons?)
 •  List
and
explain
the
four
ways
evoluLonary
change
can
take
place.
 •  DifferenLate
between
evoluLon
and
natural
selecLon.
 •  Explain
the
five
different
lines
of
evidence
for
evoluLon.
 •  Describe
2
ways
that
evoluLon
can
beobserved
today.
 •  Explain
why
effects
of
geneLc
dris
are
greater
as
populaLon
size
decreases.
 •  Compare
and
contrast
the
different
forms
of
selecLon
on
the
variaLon
within
a
populaLon.
 •  Explain
why
gene
flow
has
more
to
do
with
flow
of
alleles
rather
than
the
flow
of
genes.

 •  Compare
and
contrast
gene
flow
and
geneLc
dris.
 •  Explain
how
small
geneLc
changes
can
account
for
large
(evoluLonary)
changes
in
the
characterisLcs
of
 a
populaLon
 EvoluLon
–
Major
Unifying
Concept
of
Biology
 •  Survival
without
food…
 •  How
long
can
you
survive
 without
food?
 •  Is
it
possible
to
manipulate
 how
long
an
organism
 could
go
without
food?
 E.g.,
 5 8/4/09 EvoluLon
–
Major
Unifying
Concept
of
Biology
 •  Can
you
manipulate
how
long
an
organism
could
go
without
food?
 • In
your
lab,
you
have
5
000
Drosophila
 melanogaster
in
a
cage…
 •What
next?   EvoluLon
–
Major
Unifying
Concept
of
Biology
 •  Can
fruit
flies
evolve
so
that
they
can
resist
starvaLon
longer?
 6 8/4/09 EvoluLon
–
Major
Unifying
Concept
of
Biology
 •  Can
fruit
flies
evolve
so
that
they
can
resist
starvaLon
longer?
 GeneraLon
1 GeneraLon
2 •  Whiny
moment:
Dr.
Kelly,
fruit
flies
are
boring…why
are
we
using
 fruit
flies?

(i.e.,Why
are
fruit
flies
good
model
organisms
for
 evoluLonary
studies?)
 EvoluLon
–
Major
Unifying
Concept
of
Biology
 •  Can
fruit
flies
evolve
so
that
they
can
resist
starvaLon
longer?
 GeneraLon
1 GeneraLon
2 NOTE:
We
have
selected
for
only
1
trait
–
 starvaLon
resistance. GeneraLon
60!! •  Over
many
generaLons
of
selecLon,
the
populaLon
changes.
The
 fruit
flies
now
resist
starvaLon
much
longer.
 7 8/4/09 EvoluLon
–
Major
Unifying
Concept
of
Biology
 Some evolutionary process e.g., natural selection Generation 1 Generation 10 A change in the traits of a population over time EVOLUTION Population – group of individuals from same species that live in same area & regularly interbreed EvoluLon
&
the
diversity
of
species
 Charles ‘Chuckster’ Darwin Alfred Russel ‘Rusty’ Wallace Darwin
didn’t
come
up
with
the
THEORY
of
evoluLon…
 8 8/4/09 The
THEORY
of
EvoluLon
 Evolution: any process of change over time Biological def’n: a change in the (genetic) characteristics (i.e., allele frequencies) of a population over time But evolution is “just a theory”… Hypothesis: early stages of an idea or a model Theory: hypothesis widely accepted by the scientific community via rigorous experimentation & re-testing of results 2
Major
Unifying
Concepts
of
Biology
 1.  Theory
of
EvoluIon
by
Natural
SelecIon
 •  •  CharacterisLcs
of
a
populaLon
change
over
Lme.
(paiern)
 Individuals
with
certain
heritable
traits
produce
more
 offspring
than
those
without
those
traits.

(mechanism)
 2.  Cell
Theory
 •  •  All
organisms
are
made
up
of
cells.
(paiern)
 All
cells
come
from
pre‐exisLng
cells.
(mechanism)
 9 8/4/09 2
Major
Unifying
Concepts
of
Biology
 1.  Theory
of
EvoluIon
by
Natural
SelecIon
 •  •  CharacterisLcs
of
a
populaLon
change
over
Lme.
(paiern)
 Individuals
with
certain
heritable
traits
produce
more
 offspring
than
those
without
those
traits.

(mechanism)
 ∴ 






All
spp
are
related
by
descent
from
a
common
ancestor.
 &






All
spp
come
from
(descend)
from
other
pre‐exisLng
spp.
 2.  Cell
Theory
 •  •  All
organisms
are
made
up
of
cells.
(paiern)
 All
cells
come
from
pre‐exisLng
cells.
(mechanism)
 ∴ 






All
single‐cell
organisms
in
a
populaLon
related
to
1
common
ancestor.
 &







All
cells
in
a
mulLcellular
organism
descend
from
1
ancestral
cell
 Darwin
was
influenced
by
other
scienLsts…
 Buffon (1707-1788) - organismal differences related to environments inhabited Lamarck (1744-1829) - proposal of how evolution occurred • species changed through time • life evolved “upward into higher” forms • simplest life forms spontaneous generation • Use & disuse • “inheritance of acquired characteristics” Both: • went against idea that populations are unchanging & that variation is unimportant • stressed the importance of variation in natural populations. 10 8/4/09 Darwin
was
influenced
by
other
scienLsts…
 Hutton (1726-1797) - gradualism Lyell (1797-1875) - uniformitarianism • Both were geologists • Gradualism – slow processes over long geologic time periods – accumulation of small changes over long periods of time can add up to big changes • Uniformitarianism – present is key to past & vice-versa. Current geological processes occurred in past at same rate as today. 21
 Darwin
was
influenced
by
other
scienLsts…
 Buffon (1707-1788) - organismal differences related to environments inhabited Hutton (1726-1797) - gradualism Lamarck (1744-1829) - proposal of how evolution occurred Lyell (1797-1875) - uniformitarianism Darwin (1809-1882) - Theory of Natural Selection Darwin absorbed the ideas that: • Variation within populations is important • BIG changes can occur very gradually over long periods of time (accumulation of changes) 22
 11 8/4/09 Darwin’s
observaLons
of
geographic
similariLes
&
 differences…
 •  Darwin
observed
unexpected
paierns
 Darwin’s
observaLons
of
geographic
similariLes
&
 differences…
 •  Although
different
spp,
all
very
closely
resembled
the
1
spp
of
finch
 living
on
closest
mainland
(Ecuador).
 12 8/4/09 Darwin’s
observaLons
of
geographic
similariLes
&
 differences…
 Extinct vs. extant •  Were
glyptodonts
ancestors
of
armadillos?


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