Unit 4 Diversity of Life
Evolution
and Classification
Introduction video
http://viewpure.com/n3265bno2X0
Charles Darwin and the
Beagle
-left
England in 1831
-took 5 years to complete
-was a volunteer naturalist position
-he was 22 years old
-collected plants and animals at every stop
-spent much time on the Galapagos Islands
making observations
-noticed many variations of plants and
animals from island to island
Natural Variation - differences among individuals of a species
-found in all types of organisms
Ex: bacterial resistance to antibiotics, cows giving different amounts of
milk, fruit size
Evolution = Descent with Modification
Evolution only occurs when there is a change in gene frequency within a
population over time. Evolution is a long-term change.
Compare these two examples of change in beetle populations. Which
one is an example of evolution?
1. Beetles on a diet
Imagine a year or two of drought in which there
are few plants that these beetles can eat.
All the beetles have the same chances of survival and reproduction,
but because of food restrictions, the beetles in the population are a
little smaller than the preceding generation of beetles.
2. Beetles of a different color
Most of the beetles in the
population (say 90%) have the
genes for bright green coloration
and a few of them (10%) have a
gene that makes them more brown.
Some number of generations later,
things have changed: brown beetles
are more common than they used to
be and make up 70% of the
population
Natural selection is one of the basic mechanisms of evolution, along
with mutation, migration, and genetic drift.
Darwin's grand idea of evolution by natural selection is relatively
simple but often misunderstood. To find out how it works, imagine a
population of beetles:
Evolution by Natural Selection
-many different actions are at work in order to make natural
selection concept successful including:
1 There is variation in traits.
For example, some beetles are
green and some are brown.
OUCH!
2 There is differential
reproduction.
Since the environment can't support
unlimited population growth, not
all individuals get to reproduce to
their full potential. In this example,
green beetles tend to get eaten by
birds and survive to reproduce less
often than brown beetles do.
3 There is heredity.
The surviving brown beetles have brown
baby beetles because this trait has a
genetic basis.
4 End result:
The more advantageous trait, brown coloration, which What
allows the
happened
beetle to have more offspring, becomes more common
in theto
all the green
population. If this process continues, eventually, all individuals
in the
guys?
population will be brown.
If you have variation, differential reproduction, and
heredity, you will have evolution by natural
selection as an outcome.
Survival of the Fittest- high fitness individuals live to reproduce, low
fitness individuals perish.
Struggle for existence-members of each species compete regularly
for food, living space
An organism competes most closely with other
members of its own species, because they have
the most similar ecological needs to its own;
other species, in decreasing order of ecological
similarity, also compete and exert a negative
influence on the organism's chance of survival.
Interspecific Competition-members of different species
competing for limiting factors
Intraspecific Competition- members of the same species
competing
More Modern Evidence Which Supports The Theory of Evolution
Embryonic Development and relative ages of evolution
T
I
M
E
1
2
3
4
5
6
7
8
Match these organisms with the numbered embryo
Human, fish, salamander, turtle, chicken, pig, rabbit, calf
More Modern Evidence Which Supports The Theory of Evolution
Embryonic Development and relative ages of evolution
1
Fish
2
3
Salamander Tortoise
4
Chick
5
Pig
6
Calf
7
Rabbit
8
Human
Looking at embryonic
development can give
you a relative age as
well as
help you determine
how closely
related different
organisms are.
This is OLD School due
to the
advances in DNA
analysis
Who are you more
closely related to??
The Pig, the turtle,
then the salamander
Even more Evidence for The THEORY of EVOLUTION
Homologous Structures are of the same basic structure
but used differently in the adult
Humorus
Ulna
radius
wrist
Phalangies
The STRONGEST & MOST MODERN EVIDENCE which
SUPPORTS the THEORY of EVOLUTION
DNA
FROM A GENETIC STANDPOINT HUMANS ARE______ SIMILAR TO______
98.2%-Chimps
43%- Banana
SPECIATION
What Is a Species?
A species is a potentially interbreeding population that does not
interbreed with other such populations when there is opportunity
to do so.
How a new species develops: It all relates to a Reproductive Isolating
1.Hybridization/Artificial Selection: When 2 different species
interbreed so frequently that the resulting hybrid species will begin to
intrabreed enough to sustain itself.
A NEW SPECIES? THE POLARGRIZ
2.Adaptive radiation:
The formation of a number of
diverse species from a single
ancestral one is called an adaptive
radiation. Example: Darwin’s
Finches.
3.Geographic Isolation:
The Kaibab squirrel became
geographically isolated from the common
ancestor with its closest relative, the
Abert squirrel in the North Rim of the
Grand Canyon about 10,000 years ago.
Since then, several distinguishing
features, such as the black belly and
forelimbs have gradually evolved.
A geographic barrier (mountain
range, river, ocean, etc.)
results in reproductive isolation
and eventual changes
occur in the newly separated
species. Example: Grand
Canyon Squirrels.
Lonesome George the last Pinta Island Giant tortoise
Can you predict the different
Vegetation heights on which these
tortoises fed??
Evolution of Populations: Genetic based
Gene pools- combined genetic information of all
the members of a population.
-typically contain 2 or more alleles
for an inheritable trait
coat color in labs, mice fur color
4 Sources of Genetic Variation
1 Mutations- change in the sequence of DNA
-some may effect an individuals fitness (for better or worse)
2 Gene Shuffling- 23 pair of chromosomes can produce 8.4
million combinations of genes
-crossing over produces recombinants with different phenotypes
-Sexual reproduction produces many phenotypes but doesn’t
change frequencies
3 Single gene traits- a single gene with 2 alleles will give
you 2 phenotypes (widow’s peak)
4 Polygenic traits- traits controlled by 2 or more genes
-may have multiple alleles (human height, skin color)
-produces many genotypes ( gene combos.) and phenotypes (looks)
Artificial Selection- choosing the traits that we want to show up in
the offspring
-nature provided the variations, humans chose the ones that were useful
-Selective Breeding
There can be a down side to artificial selection. Because this
process essentially removes variation in a population, selectively
bred organisms can be especially susceptible to diseases or changes
in the environment that would not be a problem for a natural
population. Inbreeding — the mating of closely related individuals
— is also a problem. In dogs, this has resulted in breeds that have
health issues ranging from decreased life span to hip dysplasia.
What keeps Similar Species from Interbreeding to
possibly result in new species?
x
=
?
REPRODUCTIVE ISOLATION
Liger
“Hercules”
the Liger (12
ft., 900 lbs.).
Cama
Due to size difference
of the parents they
are born through
artificial
insemination, and
most noticeably they
have no hump. Their
flat backs and
durability make them
great pack animals.
Wolphin
A rare crossbreed
of a bottlenose
dolphin and a
false killer whale
this is probably
the best example
of an animal that
is half and half.
Killer whales have
88 teeth,
bottlenose
dolphins have 44
teeth and the
wolphin has 66
teeth.
1. STERILIZATION: The inability to reproduce due to having an uneven number of chromosomes.
The Mule is a cross between a donkey stallion (called a jack) and a horse mare. Hinnies are just
the opposite - a stallion horse crossed to a donkey jennet. For all purposes, hinnies and mules
are classified and shown together under the general term Mule. A mule or hinny may be a male
(horse mule or horse hinny) or a female (mare mule or mare hinny). Sometimes horse mules
(the males) are called Johns, and the mares are called Mollies. Both male and female mules
have all the correct "parts" but they are sterile and cannot reproduce. This is because horses
have 64 chromosomes and donkeys have 62 chromosomes. When they create a mule it has 63
chromosomes and those chromosomes can’t be split evenly.
Mule
Hinny
2. MECHANICAL ISOLATION: When two different species try to reproduce but are unable to do
so due to physical differences. Physical differences
prevent hybridization
3. Geographic Isolation- two populations are separated
by geographic barriers (rivers, mountains, oceans)
4. Temporal Isolation- two or more species reproduce at
different times
- some rain forest orchids open release pollen on a single
day different from the others
5. Behavioral Isolation- two populations can breed but
have different courtship rituals or other behaviors
Western Meadowlark
Eastern Meadowlark
Different Mating songs
Patterns of Evolutions in Populations do Exist
These Patterns of Natural Selection are best represented by graphs
There are 3 basic patterns of population evolution:
STABILIZING SELECTION: When the individuals in the center of the bellshaped curve have the selective advantage. The population is stable.
DIRECTIONAL SELECTION: When individuals at one end on the bell-shaped
curve have the selective advantage. Change is occurring in the population.
DISRUPTIVE SELECTION: When individuals at the upper and lower end of
the bell-shaped curve have the selective advantage. What used to be
an advantage is no longer the case
Toxic Newts video: http://viewpure.com/-bVowxq8IVM
SIBERIAN HUSKYTHE ULTIMATE SLED
DOG or
Polar Bear Lover?
NORMAL MUSCLE
DEVELOPMENT
“Wimpy”
MusclesTOO WEAK
Mr. T
Husky-TOO HEAVY
STABILIZING
SELECTION
BULL ELK HUNTING vs. NATURAL SELECTION
Larger Bull Elk w/o Hunting SPIKES w/ Hunting
DIRECTIONAL
SELECTION
Smaller Bull Elk
w/o Hunting
(SPIKE)
Large Bull w/ Hunting
HIGH SCHOOL vs. “The REAL WORLD”
Bill-Intellect
Nuclear Engineer
$145,000/yr
Mr. Former H.S. Jock
H.S. Teacher
$40,000/ yr
Scott-Band Member
City Mayor
$120,000/yr
DISRUPTIVE
SELECTION
THE FOUNDER EFFECT
If you are the first to survive and reproduce on the island then you are known as a
FOUNDER SPECIES or PIONEER SPECIES
If you are a founder species, would you expect future generations to show
characteristics associated with your genes?? (either physical, mental, or behavioral)
= Red
Original Population
1) New Population w/ Red
Square Founder species.
2) New Population w/
similar characteristics
as the original
=Blue
Which new population would you most expect
to look like the original in a century?
Population 2
3) New Population w/ Blue
circle founder species.
Review
How does a new species form
1.
2.
3.
4.
5.
Founding of a new population
Geographic Isolation
Changes in the gene pool
Reproductive Isolation
Geographic Overlap
Evolution is a THEORY which describes how organisms
change over time.
CHARLES DARWIN is considered the father of evolutionary theory.
Most of Darwin’s ideas came from his observations of the
organisms living on the GALAPOGOS ISLANDS.
Darwin published his now famous book “ON THE ORIGIN OF
SPECIES” 25 years after his return from the Galapagos Islands
DARWIN’s ideas included:
-NATURAL VARIATION: Individual organisms in nature differ from
one another. (Physical & Genetics)
Red Fox
-Organisms will produce more OFFSPRING than
will SURVIVE
-Members of each species COMPETE for
RESOURCES
Due to VARIATION between individuals, some
have ADVANTAGES while others are at a
DISADVANTAGE. This is the concept of NATURAL
SELECTION.
-Individuals best suited to the environment SURVIVE, breed, and
pass on their genes to the next generation
-Those unsuited die, or leave fewer young. This is the concept of
SURVIVAL of THE FITTEST
-Species change over time due to NATURAL SELECTION. Over time
new species arise and some go EXTINCT
-Species alive today have DESCENDED from species from the PAST
-So all species alive today have descended from forms of LIFE from
the past. This is EVOLUTION or DESCENT with MODIFICATION
SUPPORTING EVIDENCE for Darwin’s Theory:
-FOSSIL RECORDS suggest changes in a organism over time.
Learning From the Fossil Record
Species in different countries that develop
similar characteristics due to similar habitats
is GEOGRAPHIC DISTRIBUTION OF LIVING
SPECIES.
Structures, which develop from the
same embryonic tissue, but change
into different useful forms in the
adult are HOMOLOGOUS BODY
STRUCTURES
-Embryos of different animals that develop
the same way of suggesting similar ancestors
are called EMBRYONIC DEVELOPMENT.
-DNA ANALYSIS is used to show how
closely related two or more different
species are.
The moral of the story is that if
you can not adapt to changes
in your Environment then you
will get out competed & die or
not reproduce.
You have encountered this animal while backpacking in the Idaho wilderness.
What is it?
Is it the same animal as these?
How do you know?
What is its name?
Common Names
Mountain lion, Puma, Cougar, Painter, Catamount, Panther
Felis concolor
Taxonomy- the science of naming organisms and placing them into groups
To avoid confusion scientific names are used whenever possible when describing
organisms
Good Try!
- the first efforts of grouping organisms was a very lengthy descriptive
process
"Oak with deeply divided leaves that have no hairs on their undersides and
no teeth around their edges"
(Quercus palustris) Pin Oak
Introducing: Carolus Linnaeus
-Father of Taxonomy
-Highly acclaimed Botanist and
Ecologist
- Swedish
-Invented Binomial Nomenclature
1707-1778
100 Kroner (Sweden)
Carl von Linne coat of arms
Binomial Nomenclature- each species is assigned a two part name
- always written in italics
- first word is always CAPITALIZED (Genus)
- second word is always lower case (Species)
Pseudotsuga menziesii
Artemesia tridentata
(Genus) (species)
Pinus ponderosa
Bear Family Members
The bear family includes eight species: the
polar bear, American black bear, spectacled
bear, giant panda, sloth bear, sun bear, brown
bear, and Asiatic black bear.
Ursus americanus
Ursus arctos
Ailuropoda melanoleuca
*has it's own genus and species
*it is highly specialized
Ursus maritimus
How are you classified?
How do you remember the order?
King Phillip Cried Oh For Goodness
Sake or
Kings Play Chess On Fridays Generally
Speaking or
King Phillip Came Over From Germany
Saturday
Kingdom- Animalia
Phylum- Chordata- have notochords
Subphylum- Vertebrata- vertebral
column
Superclass- Tetrapoda- terrestrial, 4limbs, bony skeletons
Class- Mammalia- hair, milk glands,
endothermic
Subclass- Eutheria- offspring
develop within mother, nourished by
placenta
Order- Primata- fingers, flat nails
Family- Hominidae- upright posture,
flat face, stereoscopic vision, large
brain, hands and feet
Genus- Homo- double curved spine,
long life, long youth
Species- sapiens -well-developed
chin, high forehead, thin skull bones
Which 2 species would be more closely
related?
Canis lupus
Ursus arctos
Canis domesticus
SIX KINGDOMS of LIFE
SIX KINGDOMS of LIFE
Kingdom
When Evolved
Structure
Photosynthesis
1. Bacteria
3 to 4 billion years ago
Unicellular
Sometimes
2. Archaea
3 to 4 billion years ago
Unicellular
No
3. Protista
1.5 billion years ago
Unicellular
Sometimes
4. Fungi
1 billion years ago
Unicellular or Multicellular
No
5. Animalia
700 million years ago
Multicellular
No
6. Plantae
500 million years ago
Multicellular
Yes
Prokaryotes:- No Nucleus
Eukaryotes:- True Nucleus
Plants
Animals
Kingdom Archeabacteria
Kingdom Eubacteria
Kingdom Protista
Kingdom Fungi
Bacteria
Archaea
Eukarya
Archae
Eubacteria
Protista
Fungi
bacteria
Prokaryote ProEukaryote
Euk-
Plantae
Euk-
Animalia
Euk-
without
Unicellular Uni-
Autotroph Autoheterotroph Hetero-
Multicell
ular
AutoHetero-
Hetero-
Auto-
MultiHetero-
Eukaryote vs. Prokaryote
Eukaryotic organisms have a TRUE
Nucleus
Prokaryotic organisms have DNA or RNA
But it is NOT contained in a nucleus
Variations to the Classification System
Botanists use a division instead of phylum
The species level can be further divided:
-Animals can be divided into subspecies(ssp.)- morphologically
different and often geographically separated (see following slide)
-Fruits (plants) are divided into different varieties(var.)morphologically different but not geographically separated, some produced by
humans (see following slide)
-Bacteria are divided into different strains(str.)- biochemically
dissimilar group within a species Example: E coli
Royal Gala
Honeygold
Jonagold
Golden delicious
Braeburn
Fugi
Malus domestica
Pink Lady
Map of Wolf subspecies of North America
Canis lupus tundrarum
(Tundra wolf)
Canis lupus arctos
(Arctic wolf)
Canis lupus baileyi
(Mexican wolf)
Canis lupus crassodon
(Vancouver Island wolf)
Virus’s
• How do virus’s fit?
– Non-classifiable. They aren’t made of cells.
• Are they alive?
– No. They need a host in order to survive.
• Do they meet the requirements of living
organisms?
– No. They are not made of cells nor are they
living.