Transcript Evolution

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Evolution of life video
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VIDEO: EVOLUTION
Charles Darwin
Charles Darwin: the father of evolutionary
theory. He observed many things on the
voyage of the BEAGLE, a ship that travelled
around the world.
The Beagle traveled to remote areas such as
the Galapagos Islands and South America,
also Asia and Europe.
Charles Darwin
On his voyage Darwin noticed:
 That fossils he collected in S. America of giant
armadillos that were extinct, similar, but were not
identical to modern armadillos.
 That in the Galapagos Islands, different species of
finches (birds) collected on the islands, had
similar, but not identical beak size and shape.
The shape and size seemed to tailored to their
diets.
Charles Darwin
Darwin also noticed that the species were similar but not
identical between the Galapagos and S. America.
He theorized that species in the Galapagos descended from
species in South America.
Specifically with the finches, he thought that all the species of
finches descended from 1 common species and were
modified over time. This is how he explained the differences
between the different species.
 Darwin's Finches w/
different shaped beaks
Charles Darwin
Darwin reflected on his observations over time and
did not put out his theories right away. He
published his work “Origin of Species” long after
his initial voyage.
Darwin’s main ideas:
Evolution: biologically speaking is the process
by which a species changes over time.
Natural Selection: traits that make it easier for
a population to survive, are passed on to future
generations, this is the mechanism or driving
force behind the process of evolution.
NATURAL SELECTION 1
(Copy info where ever)
Individuals with favorable traits are more likely to
leave more offspring better suited for their
environment.
Again this is called natural selection
Example:
English peppered moth (Biston betularia)
- light and dark phases
NATURAL SELECTION 2
Black mutation in the
species became
favorable after air
pollution.
Normal (Speckled)
coloring was
advantageous before
industrial revolution.
Charles Darwin
Darwin’s influences
Lamarick: proposed that organisms changed
over time and adapted to their environment.
Malthus: an economist that theorized that
population growth which increased exponentially
could not keep increasing because the food
supply only increased linearly.
Summary
New Slide Not in outline
Darwin’s 5 points
1. Population has variations.
2. Some variations are favorable.
3. More offspring are produced than
survive
4. Those that survive have favorable traits.
5. A population will change over time.
Key Terms 1
Population: group of organisms of the same
species that live in the same area.
Species: group of the same kind of organisms,
that can mate and produce fertile offspring.
Fossil: the remains of organisms that lived a long
time ago, that are preserved in rock.
Fossil record: all known fossils in existence.
Science uses this record to study organisms of the
past.
Evolution by Natural Selection
4 steps in the process
1. Overpopulation: all populations produce
more offspring than can survive.
2. Variation: a lot of different traits exist in
population
3. Selection: some traits in a population make it
easier for the organisms to survive and breed.
4. Adaptation: over time these traits become
more common with in a population.
 Biogeography:
The study of the locations of organisms around the
world.
Often we see what was once a single population that
was separated by geography evolve into 2 separate
species with different traits adapted to their new
environments.
Geographical Isolation: when a population or part of a
population becomes separated from another part due to a
change in geography, such as the separation of the ancient
giant continent PANGEA in the above picture.
 Embryology: the study of un-born organisms.
This can be useful because many times we can see
traits in fetuses, before full development that are
similar in different species, this can show the
evolutionary relationship between organisms that
would not be thought to be related.
Embryos in the top line
start off at the very
beginning of their life
looking very similar,
but change
dramatically before
birth.
We can see an
evolutionary link by
examining the
similarities of the
embryos that can’t be
seen in the developed
fetus or organism
 Anatomy the study of body structure.
 Examples of the internal structure of organisms
than appear similar can be evidence of a common
ancestor.
Human hand
Mole foot
Bat wing
All the above are homologous structures.
– Homologous structures are similar in structure
but different in function.
– Homologous structures are evidence of a common
ancestor.
You need to write these in your
notes!!!!!!!!!
•Analogous Structures: structures with
similar functions, but with different
evolutionary origins.
 Vestigial
Structures: have no function in
present organism but may have had use in
ancestral organism.
 Analogous
Structures
Vestigial
Structures
Remains of hind or rear
limbs in whales
Analogous Structures
Homologous
Similar
Structure
Analogous
Similar
Function but
not origin or
structure
Start Here Mon
Key Terms 2
 Microevolution:
The process by which traits in a population change
over time.
Genetic drift: random affects of life that cause the
differences in passing on of different alleles from
one generation to the next.
Migration: movement of individuals in and out of
a population
Key Terms 3
Macroevolution: study of the development of
new species over time. Information can be
gathered by comparing fossil record to the living
organisms.
Convergent evolution: environment influences 2
different species into having similar adaptation
Adaptive Radiation: splitting of a species to
eventually develop into 2 or more new species.
• Convergent
evolution: describes
evolution toward
similar traits in
unrelated species.
 Divergent evolution describes
evolution toward different traits in
closely related species.
kit fox
red fox
ancestor
Key Terms 4
 Extinction: when a population or a species fails
to reproduce or dies off. This often has happened
in the fossil record
 Gradualism: many small changes w/ in a species
or population over a long time.
 Adaptive Trait: a new characteristic developed
as a result of evolution usually is beneficial.
Examples of Variation
Australian
Dessert Shrub
What are the examples
of variation here?
Population Genetics
Microevolution is studying the change in allele frequency in
a population, this can also be called POPULATION
GENETICS.
Speciation is the creation of a new species from a preexisting one, through variation (change in alleles).
Variations, in genetic terms occur through random
mutation of alleles (DNA).
If it occurs in a germ or sex cell then the new allele or trait is
put out into the entire population through reproduction
If the allele and the trait gives an organism an advantage
then that allele will be carried to future generations and
may eventually spawn a new species.
Key Terms 5
Gene Pool: all the possible alleles shared by a given
population. All the genetic possibilities in the
populations
KEY CONCEPT
A population shares a common gene pool.
Key Terms 6
Gene Flow: the movement of alleles between
populations, usually through migration.
Gene flow occurs
when individuals
join new
populations and
reproduce.
bald eagle migration
Key Terms 7
Genetic Equilibrium: a population with no genetic
change occurring. This was demonstrated by the
Harvey-Wienburg Model
•Genotype frequencies
stay the same if five
conditions are met.
no genetic drift
no gene flow
no mutations
no sexual selection
no natural selection:
These
populations are
said to be not
evolving
Key Terms 8
Non Random Mating: preferences when choosing a
mate, this will change the genotypic ratio or allele
frequency of the population. This change will not be
RANDOM.
Bottle Neck effect: Genetic drift that occurs as a result of
a drastic reduction in population by an event having
little to do with the usual forces of natural selection.
 Genetic drift changes allele frequencies due to chance
alone.
Cheetah Bottleneck
•The cheetah suffers from genetic homogeneity (Nearly
genetically equal) due to a "bottleneck" effect, which
occurred approximately 10,000 years ago simultaneous
with the last Ice Age.
•As a result, the inbreeding of the few surviving
individuals at that time created a genetic
monomorphism and a real danger for the loss of the
genus due to any sudden, environmental change.
•Genetic variation is considered essential to the longterm survival of an organism as it is acted upon by
natural selection
FOUNDER EFFECT
New Slide
Genetic drift resulting from the
colonization of a new location by a small
number of individuals.
IE: A small group of ground squirrels from an
existing population are relocated to a new
habitat. This original “FOUNDERS” of the
new population are the entire gene pool.
Key Terms 9
Adaptive Trait: Characteristics organism which
enables or enhances the probability of that
organism surviving and reproducing.
Stabilizing Traits: characteristics of organism or
population that tends to produce an equilibrium
in the population.
Behavioral Isolation: when an organism or
population acts in a way that separates it from the
rest of the population. (breeding calls, mating
dances,)
Behavioral
Isolation:
Plains Leopard Frog 02
LEOPARD FROGS
Isolation by
mating song
Chiricahua Leopard Frog 12
Key Terms 10
 Two or more species can evolve together through
co-evolution.
 evolutionary paths become connected
 species evolve in response to changes in each other
Species can become extinct.
 Extinction is the elimination of a species from Earth.
 Background extinctions occur continuously at a very low
rate.
– occur at roughly the
same rate as
speciation
– usually affects a few
species in a small area
– caused by local
changes in
environment
Extinction ( ADD TO OUTLINE)
 Humans can cause extinction of a species through
overharvesting, pollution, habitat destruction,
introduction of new predators and food
competitors, overhunting, and other influences.
Approx 784 species extinctions due to humans since
1500.
Passenger Pigeon
White Lemuroid Possum
Informational
All is not as
bleak as it
sounds there
are new species
found every
year. One of
the newest is
the Varanus
bitatawa, a new
species of
monitor lizard
TAKE EVERYTHING OFF
YOUR DESK.
NO TALKING WHEN THE
QUIZ IS BEING TAKEN.
USING THE WORDS
FROM THE WORD
BANK, WRITE THE
WORD IN THE BLANK
NEXT IT’S DEFINITION.
Classification of Life
It is necessary to name and classify organisms ,
this process is called TAXONOMY.
Scientific Nomenclature: A “language” or
method used to name different species.
Originally many different “languages” were being
used and it was very confusing.
In the 1750’s Carl Linnaeus developed a system of
binomial nomenclature. Binomial: 2-names
Classification of Life 2
Naming Rules:
 This system is to name the organism with 2
words, GENUS, SPECIES
 2 part scientific name:
genus: a shared group name with others
species: specific descriptive name, species
names are unique no 2 are the same
Example Wolves and Coyotes
Genus Canis
Canis lupus: Grey Wolf
Canis latrans: Coyote
EXAMPLES
Red Maple Tree------- Acer rubrum
Humans --------------- Homo sapiens
Cats-------------------- Felis domesticus
Lions -------------------- Panthera leo
Tiger -------------------- Panthera tigris
The Linnean System
 The Linnean System: Classifies animals and plants
into by using decreasing levels of hierarchy bases on how
similar they are in structure and form.
 DOMAIN: organized by the 3 Cell types, organelles
present, Multi or Unicellular .
 Eukarya , Bacteria or, Archaea
 KINGDOMS: 6, usually defined by number of
cells, body organization, or nutrition.
Eubacteria, Protista, Archae-bacteria, Fungi,
Plantae, Animalia
3 Domains from a common
ancestor
Levels of the taxonomy
(Taxa)
Kingdom
Phylum
Class
Order
Family
Genus
species
Genus and Species will
always be the scientific
names of organisms
Human Taxonomy:
Animalia
Chordata
Mammalia
Carnovira
Placenta
Homo
sapiens
Memory Trick
Kingdom
Phylum
Class
Order
Family
Genus
species
Remember
King
Philip
came
over
for
good
spaghetti
Classify these objects
EXAMPLES OF CLASSIFICATION
All Non-Living
EXAMPLES OF CLASSIFICATION
Narrow it down
some:
Modes of transport
EXAMPLES OF CLASSIFICATION
Narrow it down some
more:
Modes of personal
transport
EXAMPLES OF CLASSIFICATION
Narrow it down
even more:
Cars
EXAMPLES OF CLASSIFICATION
Narrow it down
even more:
Sports Cars
EXAMPLES OF CLASSIFICATION
Finally:
to a level similar to
genus and species:
Sports Cars that are red
Phylogenetic tree
 A diagram
showing the
evolutionary
connections
and common
or differing
ancestors of
species.
 Also called a
cladogram.
Take a few Minutes an do the activity.
WHALE
1.
Closely related
groups?
2. Least closely
related groups.
3. First to diverge
or separate
from common
lineage?
How and When did Life begin
The universe is over 15 Billion years old (BYO)
The earth is 4. 5 BYO
How do we know?
Radiometric Dating: Calculation of age of
object by measure the amount of isotope
decay in a matter of time.
 Isotopes are chemical that are radioactive
and will decay in a what is call a half-life.
Time Periods
 Major Eras (Periods):
1. Precambrian (Origin of Earth and Solar System)
2. Paleozoic (First signs of life. And animals)
3. Mesozoic (Dinosaurs Flowering plants and
mammals)
4. Cenozoic (Humans, modern types of Mammals)
Notes
In The beginning… it is believed? (1)
Earth’s first atmosphere was believed to be free of
oxygen. It contain Gases (CO, CO2,
H2, N2, NH3, CH4)
Therefore the first true cells were believed to be
Anaerobes (organisms that can live without oxygen).
From the anaerobes (prokaryotic cell,) we formed
Aerobic Organisms.
In The beginning… it is believed? (2)
 It is believed that the anaerobes used up all their
resources. And the heterotrophic organisms
(anaerobes) had to get energy through another
source (sunlight).
Therefore, photosynthetic organisms developed.
As a result of the oxygen being given off from the
photosynthetic organisms, Aerobes (O2 using
organisms) developed.
History of Life On Earth
ECOLOGY VOCABULARY
Biomes
Ecosystem
Population
Predation
Competition
Parasitism
Mutualism
Commensalis
m
9. Densitydependent
Factors
1.
2.
3.
4.
5.
6.
7.
8.
10. Density
11.
12.
13.
14.
15.
independent
Factors
Dominant
Species
Exotic Species
Pioneer
Species
Endangered
Species
Threatened
Species
16. Succession
17. Niche
18. Biotic Factor
19. Abiotic Factor
20. Community
21. Bio-diversity