1-19-11 History of Life

1-19-11 History of Life - Announcements

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Unformatted text preview: Announcements BIOL
1108
Principles
of
Biology
II Dr
Kathrin
Stanger
Hall, PhD
University
Tubingen,
Germany Animal
physiology • [email protected] Dr
Lisa
Donovan [email protected] Ph.D
University
of
Utah – If
you
did
not
aIend
Friday
January
14,
watch podcast
on
eLC – Homework
on
eLC
due
Friday
January
21 • Syllabus
has
been
revised,
see
eLC – We
will
not
be
making
up
missed
classes
on Saturday
January
29 – Last
day
to
drop
this
class,
Thursday
January
20 – Last
day
to
add
this
class,
Friday
January
21 1 Clicker
101 Clicker
101 At
the
beginning
of
each
class….. • Please
switch
clicker
on [email protected] search
for
a
class
(and find
it
once
I
start
a
ppt [email protected]) • If
it
takes
too
long
you can
enter
the
number
or leIer
in
<
>
on
the overhead
screen 2 • You
can
earn
full
credit (30
points)
by
answering 80%
of
all
clicker [email protected] semester
(see
syllabus) • Please
enter
your
UGA e‐mail
name
as
ID
in your
clicker
(use up/down
arrows
to find
leIers
other
than A‐E) • Please
check
before each
class
that
your
ID didn’t
change
in
your backpack • The
points
are
for
self‐ [email protected](commi_ng
to an
answer
that
you reasoned
out
to
be correct) • You
will
get
credit whether
your
answer
is actually
correct
or
not • To
get
the
full
learning (and
exam
prep)
benefit, please
make
an
honest effort
to
reason
out
the correct
answer • Thinking
skills
are
key! 3 Q:
What
is
the
current
ID
in
your clicker? 1. 2. 3. 4. 5. 4 A
Brief
History
of
Life:
EvoluEon
of
Diversity Social
security
number 810‐number UGA‐email
name I
made
it
up none Earth
~
4
billion
years
ago,
no
life 5 •
Universe
~
10‐20
billion
years
old •
Solar
system
~
4.5‐5
billion
years
old •
Earth
~
4.5
billion
years
old Earth
today,
diversity
of organisms 6 About
4‐3.8
billion
years
ago
(bya): Crust
cooled
~3.8
billion
years
ago Atmosphere
of
early
earth:
Hot! ‐carbon
monoxide
(CO),
 ‐carbon
dioxide
(CO2 ),
 ‐Nitrogen
(N2 ),
 ‐water
vapor
(H2O) ‐NO
FREE
OXYGEN,
or
just
trace
amount Earth
crust
solidifies
Bombardment
from Outer
Space
ceases 300
million
 years
 Origin
of
Life? What
organic
molecules could
have
existed? [email protected] [email protected]? Bacteria ~3.5
billion
years
ago (Major
molecular building
blocks
of life:

Membranes, DNA,
RNA,
Proteins) 8 7 What
organic
molecules
could
have
existed? What properties might primitive life have had? Miller‐Urey
experiment,
1952
(and
others
that
followed) •

tried
to
mimic
chemistry
of
early
ocean/atmosphere •

added
warmth
and
sparks
of
electricity •

analyzed
what
accumulated Membrane-like structures surrounding “protobionts” • lipids will form l iposomes in water • chemistry potentially different inside and out So
what
accumulates
in
these
experiments? •
amino
acids [email protected] •
lipids •
sugars,
etc. “RNA World” • genetic information (code) • structural/catalytic activity, can replicate itself Seminar
Today
(January
19):
4
PM

Mahler
Aud.
GA
Center
 Nobel
Laureate
Tom
Cech
 Crawling
Out
of
the
RNA
World,
from
Ribozymes
to
Telomerase 9 10 First
fossil
Prokaryotes ~3.5
billion
years
ago Crust
cooled ~3.8
billion
years
ago 3.5
by
old
filamentous
prokaryote
 from
Western
Australia? 300
million
 years
 Origin
of
Life,
One
hypothesized
scenario: “RNA‐world” Stromatolite fossil
from Michigan Bacteria
(prokaryote) ~3.5
billion
years
ago • Stromatolites,
layered
sediment
structures formed
by
mats
of

microbial
cells • Exist
today
and
found
fossilized • [email protected] 11 Modern
stromatolites 12 Bacteria ~3.5
billion
years
ago Photosynthesis
by
cyanobacteria? a) Produces
oxygen
(O2)
consumes
carbon dioxide
(C02) b) Produces
C02
consumes
O2 c) Produces
O2
and
C02 d) Consumes
O2
and
C02 Next
billion
years
or so •

Rise
of
Cyanobacteria:[email protected] •

AdapEve
radiaEon
of
Prokaryotes 


(Bacteria
and
Archaea) 13 What
happens
to
the
O2
produced
by
photosynthesis? •

O2
oxidized
iron •

soluble
Fe2+
oxidized
to
insoluble
Fe3+
compounds •

Iron
oxides
precipitated
into
rocks
([email protected]) [email protected]
years
ago •

Then
O2
could
accumulate
(0.1‐0.2%)
2.4‐0.8
billion
years
ago Extant
cyanobacteria 15 14 Rising
O2
levels •Probably
poison for many anaerobes, mass extinctions? • Survivors have antioxidants and special enzymes to neutralize oxygen • These oxygen-binding molecules could later evolve functions as oxygen carriers in aerobic organisms •New niches for aerobic Bacteria & Archaea •Leads to metabolic diversity among prokaryotes Se_ng
the
stage
for: • [email protected](~2.1
billion
years
ago) • [email protected]@cellular
eukaryotes
(~1.5
bya) 16 Endosymbiosis - Classic Model Endosymbiosis Classic About
2.1
billion
years
ago: Where
did
Eukaryotes
come
from? (Bacteria) The
Endosymbiont
Theory
was
first
proposed
by
Lynn
Margulis
in
1967.
 [email protected]was
published
in
her
 1981
book
“ [email protected] (Archaea) (Bacteria) Fossilized
eukaryotes:
Australia 17 18 What
evidence
would
provide
the
strongest support
for
theory
of
endosymbiosis? Earth
~4
billion years
ago
(bya) 3.5
bya Bacterial
fossils 3.8
bya Crust
cools • Mitochondria
have: a. no
DNA b. DNA c. DNA
similar
to
bacterial
DNA
in
sequence
and structure d. DNA
similar
to
eukaryote
nuclear
DNA
in sequence
and
structure 2.5‐2.7
bya Iron
oxides
ppt 2.1
bya Eukaryotes 2
billion
years •
Prokaryotes
diversify •
Cyanobacteria •
O2 1.5‐1.2
bya [email protected] Eukaryotes • What
about
mitochondrial
membranes? 19 2.5‐2.7
bya Iron
oxides
ppt 535‐525
million years
ago Cambrian explosion 3.8
bya Crust
cools 2.1
bya Eukaryotes (O2
~
21%) 3.5
bya Bacterial
fossils 1.5‐1.2
bya [email protected] Eukaryotes 2
billion
years •
Prokaryote
diversify •
Cyanobacteria •
O2 700‐600
million years
ago animals
appear present Also
see
pg
9 of
course packet TIME Earth
~4
billion years
ago 20 •
500
mya:
vertebrates/
land
ho •
500‐400
mya:
plants,
insects,
tetrapods •250
mya:[email protected] •
65
mya:
primates •
0.2
mya:
homo
sapiens 21 22 Fig.
25‐14 – – – – Total
exEncEon
rate (families
per
million
years): • It
has
NOT
been
a
steady
increase
of
diversity • Today’s
species
represent
~1%
of
species
ever existed • [email protected]@ons [email protected] 5
Major
or
“ Mass” [email protected]@ons

in
last
500
million
years [email protected]@ons Can
alter
ecological
roles
or
niches • [email protected]@ons 800 700 600 15 500 10 Era Period – Common
ancestor
evolves
into
many
newspecies
to
fill vacant
ecological
roles us eo tac xt. Cre ass
e 
m 
 ian rm xt. Pe ss
e a m 20 400 Dinosaurs
 rule 300 200 5 100 0 E 542 O Paleozoic S D 488 444 416 359 C Tr P 299 251 Mesozoic J 200 145 0 Cenozoic C P 65.5 Number
of
families: Rise
and
Fall
of
Dominant
Groups? N 0 Time
(millions
of
years
ago) 23 24 [email protected]@on
(~248
mya): [email protected]@on
(~65
mya): [email protected]n Siberia
wipe
out
90%
of
all
living
species Asteroid
wipes
out
85%
of
all
living
species 25 26 [email protected]@ons • [email protected]@[email protected]@on of
terrestrial
dinosaurs • The
disappearance
of
dinosaurs
(except
birds)
allowed
for
the expansion
of
mammals
in
diversity
and
size [email protected]@ons • [email protected][email protected] prokaryotes,
large
predators
in
the
Cambrian,
land
plants, insects,
and
tetrapods • [email protected]@ons
can
occur
when
organisms colonize
new
environments
with
liIle
compe@@on – Hawaiian
islands • silverswords
(plants) • Drosophila
(fruit
flies) Cartoon
of
 [email protected] [email protected] – Island
of
Madagascar • lemurs – Galapagos
Islands • 
finches 27 28 Fig.
1‐22 Insect‐eaters Warbler
finches [email protected]@ons, [email protected]@on
underway? Green
warbler
finch Certhidea
olivacea Gray
warbler
finch Certhidea
fusca Bud‐eater Seed‐eater COMMON ANCESTOR Sharp‐beaked ground
finch
Geospiza difficilis Vegetarian
finch Platyspiza
crassirostris • [email protected]@on
is
now
about
100‐ [email protected] • We
are
loosing
species
now
at
a
higher
rate than
new
species
can
evolve • Mostly
due
to
human
impact
([email protected], [email protected],
etc.) • [email protected],
could
be
headed
for [email protected]@on Mangrove
finch
Cactospiza heliobates Tree
finches Insect‐eaters Woodpecker
finch Cactospiza
pallida Medium
tree
finch Camarhynchus
pauper Large
tree
finch Camarhynchus psi:acula Small
tree
finch Camarhynchus parvulus Seed‐eaters Cactus‐flower‐ eaters Ground
finches [email protected]@on
of Finches [email protected] processes
involved? Large
cactus ground
finch Geospiza
conirostris Passenger
Pigeon Cactus
ground
finch Geospiza
scandens Small
ground
finch Geospiza
fuliginosa Medium
ground
finch Geospiza
for<s Golden
Toad Large
ground
finch Geospiza
magnirostris 29 Tasmanian
Tiger Yangtze
River
dolphin Carolina
Parakeet 30 Prokaryotes Domains: Bacteria (Eubacteria) Time million
years
ago
(mya) present Archaea Eukaryotes Eukaraya [email protected] Plants Fungi Animals 1000 2000 3000 4000 31 ...
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This document was uploaded on 08/10/2011.

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