Transcript Warm Up - Dickinson ISD

Warm Up
• Monday 1/28/13
• What is the difference between mitosis
and meiosis.
MON 1/28/13-Sub
Independent student work
Warm Up
• Tuesday 1/29/13
• Define evolution in your own words.
Evolution #1
Darwin’s Theory of Evolution
Objectives
• Define evolution
• Explain Charles Darwin’s theory of
evolution.
Darwin’s Theory of Evolution
• Evolution, is change over time, OR is the
process by which modern organisms have
descended from ancient organisms.
• A scientific theory is a well-supported
testable explanation of phenomena that have
occurred in the natural world.
Evolution is a Theory – Just like
Gravity!
• Evolution is a well
supported
explanation of
phenomena that
have occurred in
the natural world
• A theory in science
is a well tested
hypothesis, not just
a guess
Evolution is when organisms change over time.
So, modern organisms descended from ancient
ones
Charles Darwin: born in England in 1809
Sailed around the world 1831-1836
How do you think Darwin came up with
his theory?
Voyage of the Beagle
Darwin’s Journey
Factors of Darwin’s theory of
Evolution.
• Darwin observed such a large variation of
species in similar environments.
• He observed fossils
• Darwin observed that the characteristics of
many animals and plants varied noticeably
among the different islands.
• List one factor that YOU think!
What did Darwin’s
Travels reveal
• The diversity of living
species was far greater
than anyone had previously
known!!
– Diversity = Many different
kinds of species
• These observations led him
to develop the theory of
evolution!!
1. Patterns of Diversity
• Darwin visited Argentina and Australia which had
similar grassland ecosystems.
– those grasslands were inhabited by very different
animals.
– neither Argentina nor Australia was home to the sorts of
animals that lived in European grasslands.
Examples of Diversity
• He saw rabbits in England but not in
Australia even though the environment
was similar
2. Living Organisms and Fossils
• Darwin collected the preserved remains of
ancient organisms, called fossils.
• Some of those fossils resembled organisms
that were still alive today.
Living Organisms and Fossils
• Others looked completely unlike any creature he
had ever seen.
• As Darwin studied fossils, new questions arose.
– Why had so many of these species disappeared?
– How were they related to living species?
Fossils
Types of fossils
Cast
Trace fossils
Frozen or amber
mold
Imprints
Petrified fossils
Imprint
The Galapagos Island
• A group of islands off the northwest coast
of South America
• The islands are close together but have
very different climates
• Darwin observed that the characteristics of
many plants and animals varied among the
different islands.
• Examples from the Islands:
Land tortoises
Galapagos finches
More examples on the Galapagos Islands
Blue footed booby
Marine Iguanas
4. The Journey Home
• Darwin Observed that
– Many islands close together had
different climates.
– Characteristics of many plants and
animals varied greatly among the
islands
Darwin finally published his ideas in 1859
in his book “The Origin of Species” that
summarized all his findings from his trip
around the world.
Lamarck
Theory of acquired characteristics
•
Lamarck said organisms acquired traits by using
their bodies in new ways
•
These new characteristics were passed to
offspring
•
Lamarck was totally wrong!
Avid Thinking Strategy
Cartoon Project
The cartoon does not have to be funny. It should be drawn
on a blank sheet of paper with an explanation.
Cartoon
1.Single frame cartoon
2.Three color minimum. ( black and white do not count)
3.Two-line caption.
Explanation
1.State the science concept being shown.
2.Write a 2-3 sentence explanation of why the cartoon
shows the concept.
NO CLASS
• Rachel’s Challenge-no class
Warm Up
• Thursday 1-31-13
• Explain the term theory in your own
words.
Evolution #2
Fossils, Artificial Selection, & Natural
Selection
Objectives
• Define artificial selection
• Define natural selection
• State the importance of fossils in relative
dating.
Evidence of Evolution
1. Fossil Record
2. Geographic Distribution of Living
Species
3. Homologous Body structures
4. Similarities in Embryology
1. The Fossil
Record
Fossil Record provides
evidence that living
things have evolved
Fossils show the history
of life on earth and
how different groups
of organisms have
changed over time
Relative vs.
Absolute
Dating
Relative Dating
Can determine a fossil’s
relative age
Performed by estimating
fossil age compared
with that of other fossils
Drawbacks – provides no
information about age
in years
2. 2. Geographic Distribution of Living
Species
Similar animals in different locations were
the product of different lines of descent
Homologous body structures
Structures that have different
mature forms but develop
from the same embryonic
tissues.
Wings and legs all descended
from fish fins.
e.g. Wing of bat, human arm,
leg of turtle
Turtle
Alligator
Bird
Homologous Body Structures
Vestigial Organs
– traces of homologous organs in other
species
– Organ that serves no useful function
e.g. Appendix in man
Similarities in Embryology
In their early stages of development, many
animals look similar, providing evidence that
they shared a common ancestry.
Embryological development
Artificial Selection
Nature provides variation, humans select variations
that are useful.
Example - a farmer breeds only his best livestock.
1. Evolution by Natural Selection
What do you think natural selection mean? (“Nature
chooses”, chooses what? Best adaptations for
survival)
The Struggle for Existence-members of each
species have to compete for food, shelter, other
life necessities in order to survive.
Survival of the Fittest-Some individuals are better
suited for the environment. Organisms with most
favorable adaptation will survive.
Natural Selection
Natural selection is the process by which individual organisms with
favorable traits are more likely to survive and reproduce.
Fitness is the ability of an individual to survive and reproduce
in its specific environment.
Adaptation: an inherited characteristic that increases an
organism’s chance of survival.
2. Components of Natural
Selection
• Not all individuals will
be able to reproduce.
• Due to environmental
issues, illness, etc…
• DIFFERENTIAL
REPRODUCTION
Birds eat green beetles, not
brown ones.
What’s
Left?
What’s the end
result?
Components of Natural Selection
The brown
trait has a
genetic
basis.
The brown beetles
that are left will
mate and have
brown offspring.
This is called
HEREDITY.
• Finally, the brown trait
(which is more
advantageous) allows
the beetle to survive in
order to reproduce.
• Eventually, all beetles in
this population will be
brown.
• This PHENOTYPE has
been SELECTED over
the green phenotype.
Image courtesy of http://evolution.berkeley.edu/evolibrary/article/_0_0
3. Descent with Modification
• Descent with Modification- Natural selection produces
organisms that have different structures, establish
different niches or occupy different habitats.
– This causes today’s species to look different from their ancestors.
Common Descent- were derived from common ancestors
Summary of Darwin’s Theory
1. Organisms differ; variation is inherited.
2. Organisms produce more offspring than survive.
3. Organisms compete for resources.
4. Organisms with advantages survive to pass
those advantages to their children.
5. Species alive today are descended with
modifications from common ancestors.
Warm Up
• Friday 2/1/13
• What is the difference between genotype
& phenotype? Give an example of each.
Lab
Warm Up
• Monday 2/4/13
• Define artificial selection in your own
words.
Monday-SUB
• Independent student work
Avid Thinking Strategy
Design a future Creature
1. Design a future creature. ( Fake/imaginary)
2. Use at least 3 colors to illustrate the creature
3. List 5 adaptations that would provide an advantage to
the creature (natural selection)
4. Define natural selection in your own words.
( 1 sentence)
1. Give an example of natural selection ( 1 sentence)
2. Give a nonexample of natural selection ( 1 sentence )
Warm Up
• Tuesday 2-5-13
• Explain the concept “survival of the fittest”
in your own words.
Evolution #3
Population Evolution
Objectives
• Define population.
• Define gene pool.
• Compare and contrast genetic variations.
Evolution of Populations
Occurs when there
is a change in
relative frequency
of alleles
VOCABULARY REVIEW
• Evolution –
change over time
• NATURAL SELECTION –
Individuals better adapted to the
environment are able to survive and
reproductive.
– “SURVIVAL OF THE FITTEST”
NEW VOCABULARY
• POPULATION –
Group of individuals of same species
that interbreed.
• GENE POOL –
Common group of all genes present in a
population.
1. Variation and Gene Pool
Combined genetic
information of all
members.
Allele frequency =
number of times
alleles occur in a
population.
Evolution: Any change in the
relative frequency of
alleles in a population
2. Single-Gene vs. Polygenic Traits
Single-Gene trait: any trait controlled by one gene (example:
tongue rolling)
Natural selection on single-gene traits can lead to change in
allele frequencies and thus evolution. Distinct phenotype
Polygenic traits: any trait controlled by two or more genes
(example: height in human) Many Phenotypes
3. Natural selection affects the distribution of
phenotypes in three ways:
• Directional selection- Individuals at one end of
the curve have higher fitness than those in the
middle.
– Example: seed size and birds beak size.
• Stabilizing selection-Individuals near the
center of the curve have higher fitness
than those at either ends of the curve.
– Example: weight of human infants at birth
•Disruptive selection-Individuals at the upper
and lower ends of the curve have higher
fitness than those near the middle.
•Example: seed size and bird beak size.
4. Natural Selection on Polygenic Traits
Genetic Variation
Gene Flow
Movement of genes
from one population to
another.
Mutation
Sex
Sexual reproduction
causes new
combinations of genes.
Changes in DNA
1. Sources of genetic Variation in Populations
Mutations change in DNA
sequence
Gene Shuffling –
from sexual
reproduction
2. Genetic Drift
• Suppose that some organism left behind a
few more offspring than other organisms.
• The ones that are left are the “lucky” ones.
– But their genes may be no more
advantageous than anyone else’s.
• Entirely random.
• Doesn’t produce adaptations, only a
mixing of the gene pool.
3.Genetic Drift changes populations
• Random change in allele frequency
causes an allele to become
common
4. Founder Effect:
genetic drift due to the
migration of a small subgroup of a population.
– Example: fruit flies migrating from mainland to
different Hawaiian Islands.
Hawaiian Honeycreepers
•Adaptive radiation – these species all
diverged from a common ancestor
(founder species)
FOUNDER SPECIES
Conditions needed for Genetic Equilibrium
1
2
3
4
5
5
SPECIATION
Speciation is the formation of new species
• As new species evolve, populations become
reproductively isolated.
1. Reproductive Isolation – Members of two
population cannot interbreed & produce
fertile offspring.
ISOLATING MECHANISMS……..
2. Behavioral Isolation - capable of
breeding but have differences in
courtship rituals (EX. Meadowlarks)
3. Geographical Isolation – Separated by
geographic barrier like rivers ,mountains,
or bodies of water (ex: squirrel)
4. Temporal Isolation – Two or more
species reproduce at different times.
Table 23.1a
Name the type of Isolation
• A. Populations on the same species of
seal live on islands too far apart to swim to
mate.
• B. Herds of caribou misinterpret each
other’s mating behavior so they fight
instead of mate.
• C. Flowers pollinating at different seasons.
Avid Thinking Strategy
• Population Evolution graphic presentation
Develop an illustration that will tell the world about
evolution of populations. (ex. genetic drift, gene pool)
1. Centerpiece of the artwork must be a slogan or
phrase.
2. Surrounding artwork ( min. of 3 colors ) must
demonstrate the concept in a real life situation.
3. End with a 1 paragraph (4-6 sentence)
explanation of how the artwork represents the
topic.
Warm Up
• Wednesday 2-6-13
• List three conditions needed for genetic
equilibrium.
Genetics Review
Periods 5 & 7
Warm Up
• Thursday 2-7-13
• Give an example of the founder effect in
the real world.
Evolution Review
th
5 & 7th Period
Warm Up
• Friday, February 8, 2013
• List the 4 biomolecules.
Objectives
1) Predict what will happen to a species if it
is geographically isolated.
2) Explain divergent evolution giving real
world examples.
Diverbird Lab
(Handout)