Download Evolution new Cole 2008

EVOLUTION
Neanderthal
Homo neanderthalensis
Modern day human
Homo sapiens
If evolution was condensed into 1 day…..
yrs.
yrs.
yrs.
yrs.
Evolution- change in organisms over time
“the diversity of living things as well as their unity may be the
result of evolution”
The theory of evolution suggests that organisms that exist
today evolved from earlier, more primitive forms over a long
period of time.
Evidence of Evolution1. Fossils-
shows common ancestry among organisms
~any remains or trace of a once- living organism
sedimentary
~found in __________________rock*,
ice, tar or amber
*sedimentary rock is a type
of rock formed from layers of
particles that settled to the
bottom of a body of water,
often containing fossils
~the ages of rocks have been determined by ___________________
radioactive dating
older, simpler
~lower layers of rock contain _______________life
forms
newer, more complex
~upper layers of rock contain _____________________life
forms
2. Comparative Anatomy- shows common ancestry among organisms
a. homologous structures-
structures in various organisms that
are similar in structure and origin
but have different functions in each
organisms
ex). whale flipper, bat wing and human arm
b. vestigial structures- structures that were once functional but no longer
are.
ex). appendix, tailbone, wisdom teeth
Discover 6/04
3.
Comparative Embryology- shows common ancestry among organisms
w/a backbone
When you compare vertebrate___________
embryos, at some point in development,
they all have similar appearances (gill slits,
tails)
Fish
Salamander
Tortoise
Chick
Hog
Cat
Rabbit Human
4. Comparative Cytology- shows common ancestry among
organisms
the study of cells
~Cytology = _____________________
~all living things are made of cells
~all cells have similar organelles with
similar functions
5. Comparative Biochemistry- shows common ancestry among
organisms
~all living things contain similar compounds
enzymes
hormones
DNA
glucose
_________________________________
~the closer the relationship between organisms, the
greater the similarity of their chemicals (humans can
use insulin from sheep and pigs!)
Theory of Spontaneous Generation
Idea that living things could arise spontaneously from things like mud,
sweat, decaying meat.
Redi disproved this theory.
A relatively simple sketch of
Redi's experiment regarding
spontaneous generation. Starting
from the left, the first flask is
capped, and no maggots grow
within it, then in the second flask
flies are kept out, but the mesh
allows maggots to grow within,
and finally flies are allowed into
the third flask where maggots
grow.
THEORIES OF EVOLUTION
1. Jean Baptiste Lamarcka. Theory of use and disuse- “use it or lose
it”. He theorized that if you need a structure
and use it , it will become more developed
over time.
Likewise, if you no longer need a structure
(appendix, tail) and stop using it, it will
decrease in size, become non-functional or
disappear.
b. Theory of Acquired CharacteristicsHe believed that traits acquired in a
lifetime are passed on to offspring
(like my acquired taste for chocolate!)
2. August Weismanndisproved Lamarck's theory of acquired characteristics. His experiment: he
removed the tails of mice, mated them and all of the offspring HAD tails!
Other examples
that support
Weismann:
dog breeds with
clipped tails and
ears, circumcision
3. Charles Darwin- theorized that evolution occurred as a result of
Natural Selection.. The main points of his
theory:
a. overproduction- most species produce
more offspring than can
survive because of limited
food and space
b. competition-
overproduction leads to a
struggle for available
food, water, space and
mates
c. survival of the fittest~variations among individuals make
some better adapted or more “fit ”
~the “fit” survive because they are
best adapted to the environment
~(the “fit” are not necessarily the
strongest)
Look at these examples of “fit” organisms: leaf fish, frog, spider, ptarmagin
d. natural selection- nature “selects” organisms with optimal traits (the
“fittest”) to survive and be the parents of the next generation.
This next generation will inherit the favorable characteristics that
enabled their parents to survive & reproduce
e. speciation- when a new species arises with helpful
variations/adaptations that have accumulated over many
generations
An older Darwin
Survival of the fittest……this tree has adapted to grow on the side of a hill
(Thatcher Park, 9/05)
MODERN THEORY OF EVOLUTION
a.
Today’s theorists accept Darwin’s ideas of natural
selection, BUT Darwin’s theory DID NOT address
how variations arise in a population.
For example, why do some giraffes have long necks
and some have short ones?
The answer is from gene mutation and random
recombination of genes during _________________
fertilization
The same thing goes for humans. We’re all different
because of mutations and combination of genes from our
different parents.
b. natural selection: nature has selected the fittest organisms in
the following instances:
~insects that are resistant to pesticides (are fit enough to
survive and reproduce)
~bacteria that are resistant to antibiotics (are fit enough to
survive and reproduce). You’ve all probably been on antibiotics
and have noticed that you’ve taken different brands. That’s
because the bacteria build up a resistance to the old
antibiotics.
c. Geographic Isolation~small population becomes isolated (mountain range, body of
water, Pangea)
~they adapt to their new environment and become so different
that they can no longer interbreed with the original population
~this inability to breed with the original population is called
________________________________
reproductive isolation
~over time , this leads to
the development of a new species
speciation:_____________________________
ex). Darwin’s finches on the Galapagos Islands
d. Rate of Change- there are 2 different theories on how long it takes
for evolution to occur:
1. Gradualism- evolution occurs gradually, slowly and continuously
2. Punctuated Equilibrium- when species have long periods of
stability and then have sudden, brief intervals of major change.
Gradualism
PunctuatedEquilibrium
II. The Heterotroph Hypothesis...how did life begin on earth???
primitive
conditions
inorganic materials
“hot, thin soup”:
gases: -NH3 (ammonia)
-CH4 (methane)
-H2 (hydrogen)
sun and lightning provided
the ENERGY needed to
SYNTHESIZE materials
small organic molecules formed (sugars, amino
acids)
Stanley Miller reproduced this theory in his lab
sun, lightning and energy=
SYNTHESIS
Video clip, S.
Miller’s expt
15 mins
****
large organic molecules were formed (proteins,
carbs)
Sidney Fox reproduced this theory in his lab
large molecules clumped together
aggregates (colonies) were now present
These were heterotrophic (no CO2 available)
they reproduced!
these aggregates are now considered ALIVE
BECAUSE THEY CAN REPRODUCE
no free oxygen
these heterotrophs were anaerobic
heterotrophs produced CO2
during respiration/fermentation
photosynthesis now possible
autotrophs evolved
produced oxygen
aerobes evolved
Quick Summary
Heterotrophs
anaer.
resp
CO2 given off
photosynthesis
2
autotrophsO
aerobes
produced
(fossils, comparisons)
you cannot inherit acquired
characteristics
(simpler)
(mutation & crossing-over)
survival of the fittest
Pine bush, rainforest
An increase in biodiversity increases the stability of an
environment
evolution
fossils
comparative biochem
homologous
vestigial
Darwin
Lamarck
speciation
gradualism
punctuated
equil.
reproductive
geographic
spontaneous
generation
Origin of life
aggregate
O2
photosyn
They were anaerobic
respiration or ferm
sun,
lightning,
radiation
Notes:
The Unity and Diversity of Living Things
All living things have the potential to carry out life functions.
This is one fact that unites living things.
But, living things are not the same. There are billions of different
living things. How do we tell them apart? How do we keep
them organized?
Biological Diversity
(don’t put in notes)
Edward Wilson, 1999
The total # of kinds of plants, animals and microorganisms known to science
(those which have a scientific name) is about 1.4 million. But, the actual #
is estimated to be between 10 and 80 million. “We don’t know even to the
nearest, the amount of diversity in the world.”
Out of the 1.4 million named organisms, there are approximately
750,000 insects
242,428 plants
123,151 arthropods
46,983 fungi
19,056 fish
9,048 birds
4,000 mammals
Humanity is creating a radical new environment too quickly to allow species
to adjust. Species need thousands of years (maybe millions) to assemble
complex genetic adaptations. Most of life is consequently at risk (of
extinction)”
……this is why human impact is directly related to the environment.
Now, back to notes….
The Diversity of Life
In order to study the billions of living organisms, scientists need to
have an organized system: a classification system.
Taxonomy is the branch of Biology that studies classification.
Hundreds of years ago, scientists classified living organisms into 2 groups
called kingdoms.
Plant
Animal
But, they kept discovering organisms (ex. mushrooms) that didn’t fit into
either kingdom.
Today, we use a 5 kingdom classification system:
1. Monera
2. Protista
3. Fungi
4. Plant
5. Animal
But, even these groups are too broad to have an organized system so the
kingdoms are broken down into smaller & smaller groups:
Kingdom
Broadest, largest group
Phylum
Class
Order
Family
Genus
Smallest, most specific
Species
(hint: species~specific)
How do we place organisms in the proper K,P,C,O,F,G,S?
We examine them and group them according to the following:
1. evolutionary relationships (did they come from the same
ancestor?)
2. the presence (eukaryotic) or absence (prokaryotic) of a
nuclear membrane within the cell.
3. unicellular or multicellular?
4. type of nutrition (heterotrophic or autotrophic)
Kingdom
Characteristics
Monera
•most primitive kingdom
•lacks a nuclear membrane
(prokaryotic)
•some organelles
Protista
•mostly unicellular
•eukaryotic
a. protozoa
b. algae
heterotrophic
autotrophic
Examples
•bacteria
•blue green algae
paramecium
ameba
spirogyra
Kingdom
Characteristics
•Eukaryotic
•Multicellular
Fungi
•Have branched filaments
called rhizoids (like roots) that
secrete digestive enzymes into
the surface that the fungi is on.
The fungi then absorb the
digested material
•heterotrophic
Examples
mushroom
yeast
bread mold
athlete’s foot fungus
see next slide
Plants
a. Bryophytes
b. Tracheophytes
•multicellular
•photosynthetic
•autotrophic
lack vascular tissue (xylem, phloem)
have no true roots, stems, leaves
do have vascular tissue and true
roots, stems, leaves
moss
fern
water lily
sycamore tree
pores
•hollow body cavity
•2 cell layers
flatworms
•round worms
•parasitic
sponges
hydra
jellyfish
planaria
tapeworm
liver fluke
trichina
hookworm
heartworm
segmented worms earthworm
leech
soft-bodied
2 shells
clams, oysters
1 shell: snail
no shell: slug, octopus, squid
lobster, crab, shrimp
exoskeleton (chitin) centipedes: 60 legs
jointed
appendages
millipedes : 600 legs
spiders, scorpions
bees, beetles, cockroaches
starfish
sea cucumber
spiny skinned
endoskeleton
dorsal nerve cord
brittle star
sea urchin
many including:
reptiles
birds
mammals
prokaryote
eukaryote………………………………………..
hetero but
chemosyn
in
archaebact
no
uni
hetero
no
uni
bacteria,
ameba,
blue-green
paramecium
algae
auto
yes
uni/
colony
spirogyra
hetero
auto
hetero
no
yes
no
multi
multi
multi
mushroom
fern
human
bread mold
tree
dog
Scientific Naming
There is a naming system called binomial nomenclature
two
name
naming system
Just like we all have a first and a last name, so do organisms.
Scientists refer to organisms by their genus (1st name) and species
(2nd name)
Ex). Felis domesticus = common house cat
genus
species
Rules for using scientific names:
1. Genus is always capitalized
2. Species is always lower case
3. Both words are either underlined or italicized
Note: a species is defined as a group of organisms that can mate and produce
fertile offspring
G
s
3
11
8
9
6
1
7
2
10
4
5
coccus
Diplococcus pneumonia
Bacillus botulinum
Bacillus tetani
Bacillus anthracis
strep
Bacillus
diplo
Organizes by structure, shape, arrangement
Dipteron cyclops
Helikopteron bacillus
Dipteron polyoculus
Sessilis terretris
Podus cyclops
Sessilis aquatilis
Podus biantennae
Podus anoculus
Podus monoantennae
Podus triantennae
Helikopteron coccus