evolution - honors biology
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2011-2012Honors Biology
Evolution
Tuesday, March 6, 12
Honors Biology
What is Evolution?
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Evolution!
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Evolution! Evolution!
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Evolution! Evolution!
Isn’t evolution just a THEORY?
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Evolution! Evolution!What about religion?
Isn’t evolution just a THEORY?
Tuesday, March 6, 12
Honors Biology
What is Evolution?§ Evolution
u changes in living organisms over timeu explains how modern organisms have
descended from ancient organisms
Evolution!
Evolution! Evolution!
Why do we accept this as aScientific Principle?
What about religion?
Isn’t evolution just a THEORY?
Tuesday, March 6, 12
Honors Biology
Theory?
Tuesday, March 6, 12
Honors Biology
Theory?§ a well-tested explanation that unifies a
broad range of observations
Tuesday, March 6, 12
Honors Biology
Theory?§ a well-tested explanation that unifies a
broad range of observations
Cell Theory
Tuesday, March 6, 12
Honors Biology
Theory?§ a well-tested explanation that unifies a
broad range of observations
Cell Theory
Heliocentric Solar SystemTuesday, March 6, 12
Honors Biology
Theory?§ a well-tested explanation that unifies a
broad range of observations
Cell Theory
Heliocentric Solar System
Plate Tectonic Theory
Tuesday, March 6, 12
Honors Biology
Religion?
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Based on faith
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed
§ Based on faith
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed
§ Based on faith§ Accepted without
evidence
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed§ TESTABLE
§ Based on faith§ Accepted without
evidence
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed§ TESTABLE
§ Based on faith§ Accepted without
evidence§ NOT TESTABLE
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed§ TESTABLE§ Self correcting
§ Based on faith§ Accepted without
evidence§ NOT TESTABLE
Tuesday, March 6, 12
Honors Biology
Religion?SCIENCE RELIGION§ Guided by natural
law§ Explains what is
observed§ TESTABLE§ Self correcting
§ Based on faith§ Accepted without
evidence§ NOT TESTABLE§ Deals with
supernatural
Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth
Diversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth
Diversity of Life on EarthBiodiversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth§ How do we know this?
Diversity of Life on EarthBiodiversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth§ How do we know this?
Diversity of Life on Earth
OBSERVATION
Biodiversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth§ How do we know this?
Diversity of Life on Earth
OBSERVATION
How did all these creatures come about?
Biodiversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ There are many different creatures on Earth§ How do we know this?
Diversity of Life on Earth
OBSERVATION
How did all these creatures come about?What accounts for all this biological diversity?
Biodiversity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
cells
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
cells
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
DNAcells
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics
DNAcells
Unity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics§ How do we know this?
DNAcells
Unity of Life on Earth
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics§ How do we know this?
DNAcells
Unity of Life on Earth
OBSERVATION
Tuesday, March 6, 12
Honors Biology
What do we know?§ All creatures have common characteristics§ How do we know this?
DNAcells
Unity of Life on Earth
How could all of life have the same basic features?
OBSERVATION
Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
TESTING & OBSERVATION
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
Radioactive Datingof the Rocks
TESTING & OBSERVATION
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
Radioactive Datingof the Rocks
TESTING & OBSERVATION
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
Radioactive Datingof the Rocks
TESTING & OBSERVATION
Life is very old!
Tuesday, March 6, 12
Honors Biology
What do we know?§ The Earth is very old§ How do we know this?
Radioactive Datingof the Rocks
TESTING & OBSERVATION
Life is very old!
What’s happened to life during those billions of years?Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ Creatures have changed over time
Tuesday, March 6, 12
Honors Biology
What do we know?§ Creatures have changed over time
Tuesday, March 6, 12
Honors Biology
What do we know?§ Creatures have changed over time
Fossil Record
Tuesday, March 6, 12
Honors Biology
What do we know?§ Creatures have changed over time§ How do we know this?
Fossil Record
Tuesday, March 6, 12
Honors Biology
What do we know?§ Creatures have changed over time§ How do we know this?
Fossil Record
OBSERVATION
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures that lived in the past don’t
exist today
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures that lived in the past don’t
exist today
Origin of new species
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures that lived in the past don’t
exist today
Origin of new species
OBSERVATION
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ The creatures alive today haven’t
always been around
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ The creatures alive today haven’t
always been around
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ The creatures alive today haven’t
always been around
Different species lived in the past
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ The creatures alive today haven’t
always been around
Different species lived in the past
OBSERVATION
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures in the past looked like
living ones we see today
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures in the past looked like
living ones we see today
“Family Tree”Relatives with similar,
but not the same traits
Tuesday, March 6, 12
Honors Biology
What has the fossil record shown us?§ Many creatures in the past looked like
living ones we see today
“Family Tree”Relatives with similar,
but not the same traits
OBSERVATION
Tuesday, March 6, 12
Honors Biology
Quick review, so far….
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old§ Life is very old
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old§ Life is very old§ Life has changed over time
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old§ Life is very old§ Life has changed over time§ The changes have been little changes over
long periods of time
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old§ Life is very old§ Life has changed over time§ The changes have been little changes over
long periods of time
Evolution
Tuesday, March 6, 12
Honors Biology
Quick review, so far….§ Many different species alive today§ All life shares common characteristics§ The Earth is very old§ Life is very old§ Life has changed over time§ The changes have been little changes over
long periods of time
Evolution
But how does this work?Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals
Variation
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals§ How do we know this?
Variation
Tuesday, March 6, 12
Honors Biology
What do we know?§ Populations are a mix of different individuals§ How do we know this? OBSERVATION
Variation
Tuesday, March 6, 12
Honors Biology
What do we know?
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support
Over-production
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support§ Not everybody survives
Over-production
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support§ Not everybody survives
Over-production
Competition
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support§ Not everybody survives§ How do we know this?
Over-production
Competition
Tuesday, March 6, 12
Honors Biology
What do we know?§ Organisms have more offspring than the
environment can support§ Not everybody survives§ How do we know this?
OBSERVATION
Over-production
Competition
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Tuesday, March 6, 12
Honors Biology
How does that work?
Variation
Tuesday, March 6, 12
Honors Biology
How does that work?
Variation
Over-Production & Competition
Tuesday, March 6, 12
Honors Biology
How does that work?
Variation
Over-Production & Competition
Adaptation
Tuesday, March 6, 12
Honors Biology
How does that work?
Variation
Over-Production & Competition
Nature selects the ones that “fit” the environment better … survive & reproduce
Adaptation
Tuesday, March 6, 12
Honors Biology
How does that work?
Variation
Over-Production & Competition
Natural Selection
Nature selects the ones that “fit” the environment better … survive & reproduce
Adaptation
Tuesday, March 6, 12
Honors Biology
What determines survival?
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Adaptations
Tuesday, March 6, 12
Honors Biology
What determines survival?§ Natural Selection
u traits that help individuals survive§ survive predators§ survive disease§ compete for food§ compete for territory
u traits that help individuals reproduce§ attracting a mate§ compete for nesting sites§ successfully raise young
Survival & Reproduction of the Fittest
Adaptations
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…not the fastest…
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…not the fastest…not the biggest…
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…not the fastest…not the biggest……the fittest!
Tuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…not the fastest…not the biggest……the fittest!
the traits that help an organism fit the environment better to
survive & reproduceTuesday, March 6, 12
Honors Biology
Survival & Reproduction of the fittest
not the strongest…not the bravest…not the fastest…not the biggest……the fittest!
the traits that help an organism fit the environment better to
survive & reproduce
Adaptations
Tuesday, March 6, 12
Honors Biology
Evolution explains Unity & Diversity
Tuesday, March 6, 12
Honors Biology
Evolution explains Unity & Diversity§ Only evolution explains both u unity of life
§ similarities between all living thingsu diversity of life
§ wide variety of different creatures on Earth
Tuesday, March 6, 12
Honors Biology DNA
Evolution explains Unity & Diversity§ Only evolution explains both u unity of life
§ similarities between all living thingsu diversity of life
§ wide variety of different creatures on Earth
Tuesday, March 6, 12
Honors Biology DNA
Evolution explains Unity & Diversity§ Only evolution explains both u unity of life
§ similarities between all living thingsu diversity of life
§ wide variety of different creatures on Earth
Tuesday, March 6, 12
Honors Biology
Survival & reproduction of the fittest bug…
Tuesday, March 6, 12
Honors Biology
Survival & reproduction of the fittest bug…
Tuesday, March 6, 12
2011-2012Honors Biology
Insect eaters
Bud eater
Seed eaters
Cactuseater
Warblerfinch
Tree
finc
hes Ground finches
Charles Darwinand
Evolution
Tuesday, March 6, 12
Honors Biology
Charles Darwin
Tuesday, March 6, 12
Honors Biology
Charles Darwin
Tuesday, March 6, 12
Honors Biology
Charles Darwin§ Proposed a way how
evolution worksu How did creatures
change over time?u by natural selection
Tuesday, March 6, 12
Honors Biology
Charles Darwin§ Proposed a way how
evolution worksu How did creatures
change over time?u by natural selection
§ Collected a lot of evidence to support his ideas u 1809-1882u British naturalist
Tuesday, March 6, 12
Honors Biology
Voyage of the HMS Beagle
Tuesday, March 6, 12
Honors Biology
Robert Fitzroy
Voyage of the HMS Beagle§ Invited to travel around the world
u 1831-1836 (22 years old!)u makes many observations of nature
§ main mission of the Beagle was to chart South American coastline
Tuesday, March 6, 12
Honors Biology
Voyage of the HMS Beagle
Tuesday, March 6, 12
Honors Biology
Voyage of the HMS Beagle§ Stopped in Galapagos Islands
u 500 miles off coast of Ecuador
Tuesday, March 6, 12
Honors Biology
Voyage of the HMS Beagle§ Stopped in Galapagos Islands
u 500 miles off coast of Ecuador
Tuesday, March 6, 12
Honors Biology
GalapagosRecently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland.
800 km west of EcuadorTuesday, March 6, 12
Honors Biology
GalapagosRecently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland.
800 km west of EcuadorTuesday, March 6, 12
Honors Biology
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Many of Darwin’s observations made him wonder… Why?
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Many of Darwin’s observations made him wonder… Why?
Darwin asked:Why were these creatures found only on the Galapagos Islands?
Darwin found…many unique species
Tuesday, March 6, 12
Honors Biology
Darwin found…clues in the fossils
Tuesday, March 6, 12
Honors Biology
Darwin found:Evidence that creatures have changed over time
Darwin found…clues in the fossils
Tuesday, March 6, 12
Honors Biology
present day Armadillos
Darwin found:Evidence that creatures have changed over time
Darwin found…clues in the fossils
Tuesday, March 6, 12
Honors Biology
present day Armadillos
Darwin found:Evidence that creatures have changed over time
ancient Armadillo
Darwin found…clues in the fossils
Tuesday, March 6, 12
Honors Biology
present day Armadillos
Darwin found:Evidence that creatures have changed over time
ancient Armadillo
Darwin asked:Why should extinct armadillos & modern armadillos be found on same continent?
Darwin found…clues in the fossils
Tuesday, March 6, 12
Honors Biology
Darwin found:Different shells on tortoises on different islands
Tuesday, March 6, 12
Honors Biology
Darwin found:Different shells on tortoises on different islands
Tuesday, March 6, 12
Honors Biology
Darwin found:Different shells on tortoises on different islands
Darwin asked:Is there a relationship
between the environment & what an animal
looks like?
Tuesday, March 6, 12
Honors Biology
Darwin found… birdsDarwin found:Many different birds on the Galapagos Islands.
Tuesday, March 6, 12
Honors Biology
Darwin found… birdsDarwin found:Many different birds on the Galapagos Islands.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birdsDarwin found:Many different birds on the Galapagos Islands.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birdsDarwin found:Many different birds on the Galapagos Islands.
He thought he found very different kinds…
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birds
Finch?
Darwin found:Many different birds on the Galapagos Islands.
He thought he found very different kinds…
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birds
Finch? Sparrow?
Darwin found:Many different birds on the Galapagos Islands.
He thought he found very different kinds…
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birds
Finch? Sparrow?
Woodpecker?
Darwin found:Many different birds on the Galapagos Islands.
He thought he found very different kinds…
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found… birds
Finch? Sparrow?
Woodpecker? Warbler?
Darwin found:Many different birds on the Galapagos Islands.
He thought he found very different kinds…
Tuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Tuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Tuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Small ground finch
Tuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Small ground finch
Warbler finchTuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Small ground finch
Warbler finch Tree finchTuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Small ground finch
Warbler finch Tree finch
But there is only one species of finch on the mainland!
Tuesday, March 6, 12
Honors Biology
Darwin was amazed to find out: All 14 species of birds were finches…
Finch? Sparrow?
Woodpecker? Warbler?
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found… a lot of finches
Large ground finch
Small ground finch
Warbler finch Tree finch
But there is only one species of finch on the mainland! Darwin asked:
If the Galapagos finches came from the mainland, why are they
so different now?
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Large ground finch
Small ground finch
Warbler finch Tree finch
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Small ground finch
Warbler finch Tree finch
Big seed eater
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Warbler finch Tree finch
Big seed eater Small seed eater
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Tree finch
Big seed eater Small seed eater
Insect eater
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
n different beaks are inherited variations
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
n different beaks are inherited variations
n serve as adaptationsthat help birds compete for food
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
n different beaks are inherited variations
n serve as adaptationsthat help birds compete for food
n these birds survive & reproduce
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
n different beaks are inherited variations
n serve as adaptationsthat help birds compete for food
n these birds survive & reproduce
n pass on the genes for those more fit beaks
Tuesday, March 6, 12
Honors Biology
Finch? Sparrow?
Woodpecker? Warbler?
The finches cinched it!
Big seed eater Small seed eater
Insect eater Leaf & bud eater
Darwin said:Ahaaaa!
A flock of South American finches
were stranded on the Galapagos…
Darwin found: The differences between species of finches were associated with the different food they ate.
n different beaks are inherited variations
n serve as adaptationsthat help birds compete for food
n these birds survive & reproduce
n pass on the genes for those more fit beaks
n over time nature selected for different species with different beaks
Tuesday, March 6, 12
Honors Biology
Relationship between species (beaks) & food
Tuesday, March 6, 12
Honors Biology
Relationship between species (beaks) & food
Tuesday, March 6, 12
Honors Biology
Darwin’s finches
Tuesday, March 6, 12
Honors Biology
Darwin’s finches§ Darwin’s conclusions
u variations in beaks § differences in beaks in the original flock§ adaptations to foods available on islands
u natural selection for most fit§ over many generations, the finches were selected
for specific beaks & behaviorsu offspring inherit successful traits
§ accumulation of winning traits:both beaks & behaviors
u separate into different species
Tuesday, March 6, 12
Honors Biology
From 1 species to 14 species…
Tuesday, March 6, 12
Honors Biology
Warbler finch
Woodpecker finch
Small insectivorous
tree finchLarge
insectivoroustree finch
Vegetariantree finch
Cactus finch
Sharp-beaked finch
Small groundfinch
Mediumground finch
Large groundfinch
Insect eaters
Bud eater
Seed eaters
Cactuseater
Warblerfinch
Tree
finc
hes Ground finches
From 1 species to 14 species…
Tuesday, March 6, 12
Honors Biology
Warbler finch
Woodpecker finch
Small insectivorous
tree finchLarge
insectivoroustree finch
Vegetariantree finch
Cactus finch
Sharp-beaked finch
Small groundfinch
Mediumground finch
Large groundfinch
Insect eaters
Bud eater
Seed eaters
Cactuseater
Warblerfinch
Tree
finc
hes Ground finches
variation
From 1 species to 14 species…
Tuesday, March 6, 12
Honors Biology
Warbler finch
Woodpecker finch
Small insectivorous
tree finchLarge
insectivoroustree finch
Vegetariantree finch
Cactus finch
Sharp-beaked finch
Small groundfinch
Mediumground finch
Large groundfinch
Insect eaters
Bud eater
Seed eaters
Cactuseater
Warblerfinch
Tree
finc
hes Ground finches
variation natural selection for best survival & reproduction
From 1 species to 14 species…
Tuesday, March 6, 12
Honors Biology
Earlier ideas on Evolution
Tuesday, March 6, 12
Honors Biology
§ LaMarcku evolution by acquired traits
§ creatures developed traits during their lifetime
§ give those traits to their offspring
u example§ in reaching higher
leaves giraffes stretch their necks & give the acquired longer neck to offspring
u not accepted as valid
Earlier ideas on Evolution
Tuesday, March 6, 12
Honors Biology
§ LaMarcku evolution by acquired traits
§ creatures developed traits during their lifetime
§ give those traits to their offspring
u example§ in reaching higher
leaves giraffes stretch their necks & give the acquired longer neck to offspring
u not accepted as valid
Earlier ideas on Evolution
Tuesday, March 6, 12
Honors Biology
Darwin’s view of Evolution
Tuesday, March 6, 12
Honors Biology
Darwin’s view of Evolution
Tuesday, March 6, 12
Honors Biology
Darwin’s view of Evolution§ Darwin
u giraffes that already have long necks survive better
u leave more offspring who inherit their long necks§ variation§ selection & survival§ reproduction &
inheritance of more fit traits
Tuesday, March 6, 12
Honors Biology
Darwin’s view of Evolution§ Darwin
u giraffes that already have long necks survive better
u leave more offspring who inherit their long necks§ variation§ selection & survival§ reproduction &
inheritance of more fit traitsü
Tuesday, March 6, 12
2011-2012Honors Biology
Evidence for Evolutionby
Natural Selection
Tuesday, March 6, 12
2011-2012Honors Biology
Evidence for Evolutionby
Natural Selection
Hunting for evolution clues… Elementary, my dear, Darwin!
Tuesday, March 6, 12
Honors Biology
1. Fossil record
Tuesday, March 6, 12
Honors Biology
1. Fossil record§ Layers of rock contain fossils
u new layers cover older ones§ creates a record over time
u fossils show a series of organisms have lived on Earth § over a long period of time
Tuesday, March 6, 12
Honors Biology
Fossils tell a story…
Tuesday, March 6, 12
Honors Biology
Fossils tell a story…
the Earth is old
Tuesday, March 6, 12
Honors Biology
Fossils tell a story…
the Earth is old
Life is old
Tuesday, March 6, 12
Honors Biology
Fossils tell a story…
the Earth is old
Life is old
Life on Earth has changed
Tuesday, March 6, 12
Honors Biology
Fossil of Archaeopteryx§ lived about 150 mya§ links reptiles & birds
Today’s organisms descended from ancestral species
Evolution of birds
Tuesday, March 6, 12
Honors Biology
Fossil of Archaeopteryx§ lived about 150 mya§ links reptiles & birds
Today’s organisms descended from ancestral species
Evolution of birds
Tuesday, March 6, 12
Honors Biology
Fossil of Archaeopteryx§ lived about 150 mya§ links reptiles & birds
Today’s organisms descended from ancestral species
Evolution of birds
Tuesday, March 6, 12
Honors Biology
Land Mammal
????
Ocean Mammal
Tuesday, March 6, 12
Honors Biology
Land Mammal
????
Where are the
intermediate
fossils?
Ocean Mammal
Tuesday, March 6, 12
Honors Biology
Land Mammal
????
Where are the
intermediate
fossils?
Ocean MammalSomeone’s idea of a joke!
Tuesday, March 6, 12
Honors Biology
Land Mammal
????
Where are the
intermediate
fossils?
Ocean MammalSomeone’s idea of a joke!
But the joke’s on them!!
We found the fossil — no joke!
Tuesday, March 6, 12
Honors Biology
Land Mammal
???
Ocean MammalSomeone’s idea of a joke!
But the joke’s on them!!
We found the fossil — no joke!
Tuesday, March 6, 12
Honors Biology
Land Mammal
??
Ocean MammalSomeone’s idea of a joke!
But the joke’s on them!!
We found the fossil — no joke!
Tuesday, March 6, 12
Honors Biology
Land Mammal
?
Ocean MammalSomeone’s idea of a joke!
But the joke’s on them!!
We found the fossil — no joke!
Tuesday, March 6, 12
Honors Biology
Land Mammal
Ocean MammalSomeone’s idea of a joke!
But the joke’s on them!!
Complete seriesof transitional
fossils
We found the fossil — no joke!
Tuesday, March 6, 12
Honors Biology
Evolution from sea to land
Tuesday, March 6, 12
Honors Biology
Evolution from sea to land§ 2006 fossil discovery of early tetrapod
u 4 limbs
Tuesday, March 6, 12
Honors Biology
Evolution from sea to land§ 2006 fossil discovery of early tetrapod
u 4 limbs§ Missing link from sea to land animals
Tuesday, March 6, 12
Honors Biology
3. Anatomical record
Tuesday, March 6, 12
Honors Biology
3. Anatomical record
Tuesday, March 6, 12
Honors Biology
3. Anatomical recordAnimals with different structures on the surface
Tuesday, March 6, 12
Honors Biology
3. Anatomical recordAnimals with different structures on the surface
But when you look under the skin…
Tuesday, March 6, 12
Honors Biology
3. Anatomical recordAnimals with different structures on the surface
But when you look under the skin…
It tells an evolutionary story of common ancestors
Tuesday, March 6, 12
Honors Biology
Compare the bones§ The same bones under the skin
u limbs that perform different functions are built from the same bones
Tuesday, March 6, 12
Honors Biology
Compare the bones§ The same bones under the skin
u limbs that perform different functions are built from the same bones
Tuesday, March 6, 12
Honors Biology
Compare the bones§ The same bones under the skin
u limbs that perform different functions are built from the same bones
Tuesday, March 6, 12
Honors Biology
Homologous structures
Tuesday, March 6, 12
Honors Biology
Homologous structures§ Structures that come from the same origin
§ homo- = same§ -logous = information
Tuesday, March 6, 12
Honors Biology
Homologous structures§ Structures that come from the same origin
§ homo- = same§ -logous = information
§ Forelimbs of human, cats, whales, & bats u same structure
§ on the insideu same development in embryo u different functions
§ on the outsideu evidence of common ancestor
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…
Solving a similar problem with a similar solutionTuesday, March 6, 12
Honors Biology
But don’t be fooled by these…
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
usame function
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
usame functionudifferent structure & development
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
usame functionudifferent structure & development
§ on the inside
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
usame functionudifferent structure & development
§ on the insideudifferent origin
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
But don’t be fooled by these…§ Analogous structures
ulook similar§ on the outside
usame functionudifferent structure & development
§ on the insideudifferent originuno evolutionary relationship
Solving a similar problem with a similar solution
How is a birdlike a bug?
Tuesday, March 6, 12
Honors Biology
Analogous structures§ Dolphins: aquatic mammal§ Fish: aquatic vertebrate
uboth adapted to life in the sea
unot closely related
Tuesday, March 6, 12
Honors Biology
Analogous structures§ Dolphins: aquatic mammal§ Fish: aquatic vertebrate
uboth adapted to life in the sea
unot closely related
Watch the tail!
Tuesday, March 6, 12
Honors Biology
Convergent evolution§ 3 groups with wings
u Does this mean they have a recent common ancestor?
Tuesday, March 6, 12
Honors Biology
Convergent evolution§ 3 groups with wings
u Does this mean they have a recent common ancestor?
Tuesday, March 6, 12
Honors Biology
Convergent evolution§ 3 groups with wings
u Does this mean they have a recent common ancestor?
NO!
Tuesday, March 6, 12
Honors Biology
Convergent evolution§ 3 groups with wings
u Does this mean they have a recent common ancestor?
Flight evolved 3 separate times — evolving similar solutions to similar “problems”
NO!
They justcame up with the
same answer!
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
Which is the fly vs. the bee?
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
fly beeTuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
fly bee
Which is the moth vs. the bee?
Tuesday, March 6, 12
Honors Biology
Convergent evolution led to mimicry§ Why do these pairs look so similar?
Monarch malepoisonous
Viceroy maleedible
fly bee moth beeTuesday, March 6, 12
Honors Biology
Vestigial organs§ Hind leg bones on whale fossils
Tuesday, March 6, 12
Honors Biology
Vestigial organs§ Hind leg bones on whale fossils
Why would whales have pelvis & leg bones if they were always sea creatures?
Tuesday, March 6, 12
Honors Biology
Vestigial organs§ Hind leg bones on whale fossils
Why would whales have pelvis & leg bones if they were always sea creatures?
Because they used to
walk on land!
Tuesday, March 6, 12
Honors Biology
Comparative embryology§ Development of embryo tells an evolutionary
story u similar structures during development
all vertebrate embryos have a “gill pouch” at one stage of development
Tuesday, March 6, 12
Honors Biology
3. Molecular record§ Comparing DNA & protein structure
u everyone uses the same genetic code! § DNA
Tuesday, March 6, 12
Honors Biology
3. Molecular record
100 20 30 40 50 60 70 80 90 100 110 120
LampreyFrogBirdDogMacaqueHuman
328 45 67 125
§ Comparing DNA & protein structureu everyone uses the same genetic code!
§ DNA
Tuesday, March 6, 12
Honors Biology
3. Molecular record
100 20 30 40 50 60 70 80 90 100 110 120
LampreyFrogBirdDogMacaqueHuman
328 45 67 125
§ Comparing DNA & protein structureu everyone uses the same genetic code!
§ DNA
§ compare common genes§ compare common proteins
Tuesday, March 6, 12
Honors Biology
3. Molecular record
100 20 30 40 50 60 70 80 90 100 110 120
LampreyFrogBirdDogMacaqueHuman
328 45 67 125
§ Comparing DNA & protein structureu everyone uses the same genetic code!
§ DNA
§ compare common genes§ compare common proteins
number of amino acids different from human hemoglobin
Tuesday, March 6, 12
Honors Biology
Building “family” treesClosely related species are branches on the tree — coming from a common ancestor
Tuesday, March 6, 12
Honors Biology
Building “family” treesClosely related species are branches on the tree — coming from a common ancestor
Tuesday, March 6, 12
Honors Biology
§ How do we know natural selection can change a population?u we can recreate a similar processu “evolution by human selection”
4. Artificial selection
Tuesday, March 6, 12
Honors Biology
§ How do we know natural selection can change a population?u we can recreate a similar processu “evolution by human selection”
4. Artificial selection
“descendants” of wild mustard
Tuesday, March 6, 12
Honors Biology
§ How do we know natural selection can change a population?u we can recreate a similar processu “evolution by human selection”
4. Artificial selection
“descendants” of wild mustard
Tuesday, March 6, 12
Honors Biology
Selective BreedingHumans create the change over time
Tuesday, March 6, 12
Honors Biology
Selective BreedingHumans create the change over time
“descendants” of the wolfTuesday, March 6, 12
Honors Biology
Artificial Selection…and the examples keep coming!
Tuesday, March 6, 12
Honors Biology
Artificial Selection…and the examples keep coming!
I liked breeding pigeons!
Tuesday, March 6, 12
Honors Biology
Artificial Selection…and the examples keep coming!
I liked breeding pigeons!
Tuesday, March 6, 12
Honors Biology
Artificial Selection gone bad!§ Unexpected
consequences of artificial selection
Tuesday, March 6, 12
Honors Biology
Artificial Selection gone bad!§ Unexpected
consequences of artificial selection
Pesticide resistance
Tuesday, March 6, 12
Honors Biology
Artificial Selection gone bad!§ Unexpected
consequences of artificial selection
Pesticide resistance
Antibiotic resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance
Tuesday, March 6, 12
Honors Biology
Insecticide resistance § Spray the field, but…
u insecticide didn’t kill all individuals§ variation
u resistant survivors reproduce
u resistance is inheritedu insecticide becomes less
& less effective
Tuesday, March 6, 12
Honors Biology
Tuesday, March 6, 12
2011-2012Honors Biology
Evolutionary ForcesWhat changes populations?
Tuesday, March 6, 12
2011-2012Honors Biology
Evolutionary ForcesWhat changes populations?
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Forces of evolutionary change§ Natural selection
u traits that improve survival or reproduction will accumulate in the population§ adaptive change
§ Genetic driftu frequency of traits can change
in a population due to chance events§ random change
Tuesday, March 6, 12
Honors Biology
Natural Selection
Tuesday, March 6, 12
Honors Biology
Natural Selection
Tuesday, March 6, 12
Honors Biology
Natural Selection§ Selection acts on any trait that affects
survival or reproductionu predation selectionu sexual selection
Tuesday, March 6, 12
Honors Biology
Sexual Selection
Tuesday, March 6, 12
Honors Biology
Sexual Selection
Tuesday, March 6, 12
Honors Biology
Sexual Selection§ Acting on reproductive success
u attractiveness to potential mateu fertility of gametesu successful rearing of offspring
Tuesday, March 6, 12
Honors Biology
Sexual Selection§ Acting on reproductive success
u attractiveness to potential mateu fertility of gametesu successful rearing of offspring
Survival doesn’t matterif you don’t reproduce!
Tuesday, March 6, 12
Honors Biology
Sexual selection
Tuesday, March 6, 12
Honors Biology
Sexual selection
Tuesday, March 6, 12
Honors Biology
Sexual selection
It’s FEMALE CHOICE, baby!
Tuesday, March 6, 12
Honors Biology
Coevolution
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Coevolution§ Two or more species reciprocally
affect each other’s evolutionu predator-prey
§ disease & hostu competitive speciesu mutualism
§ pollinators & flowers
Tuesday, March 6, 12
Honors Biology
Effects of Selection
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
giraffe neckhorse size
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
giraffe neckhorse size
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
STABILIZINGSELECTION
giraffe neckhorse size
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
STABILIZINGSELECTION
giraffe neckhorse size human birth weight
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
STABILIZINGSELECTION
giraffe neckhorse size human birth weight
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
STABILIZINGSELECTION
DISRUPTIVESELECTION
giraffe neckhorse size human birth weight
Tuesday, March 6, 12
Honors Biology
Effects of Selection§ Changes in the average trait of a population
DIRECTIONALSELECTION
STABILIZINGSELECTION
DISRUPTIVESELECTION
giraffe neckhorse size human birth weight rock pocket mice
Tuesday, March 6, 12
Honors Biology
Genetic Drift
Tuesday, March 6, 12
Honors Biology
Genetic Drift § Chance events changing frequency of traits in
a populationu not adaptation to environmental conditions
§ not selectionu founder effect
§ small group splinters off & starts a new colonyu bottleneck
§ some factor (disaster) reduces population to small number & then population recovers & expands again but from a limited gene pool
Tuesday, March 6, 12
Honors Biology
Founder effect
Tuesday, March 6, 12
Honors Biology
Founder effect§ When a new population is started
by only a small group of individualsu just by chance some rare alleles may
be at high frequency; others may be missing
u skew the gene pool of new population§ human populations that
started from small group of colonists
§ example: colonization of New World
Tuesday, March 6, 12
Honors Biology
Founder effect§ When a new population is started
by only a small group of individualsu just by chance some rare alleles may
be at high frequency; others may be missing
u skew the gene pool of new population§ human populations that
started from small group of colonists
§ example: colonization of New World
albino deer Seneca Army DepotTuesday, March 6, 12
Honors Biology
Out of Africa
50,000ya
10-20,000ya
10-20,000ya
Tuesday, March 6, 12
Honors Biology
Out of AfricaLikely migration paths of humans out of Africa
Many patterns of human traits reflect this migration
50,000ya
10-20,000ya
10-20,000ya
Tuesday, March 6, 12
Honors Biology
Bottleneck effect
Tuesday, March 6, 12
Honors Biology
Bottleneck effect§ When large population is drastically reduced
by a disasteru famine, natural disaster, loss of habitat…u loss of variation by chance event
§ alleles lost from gene poolw not due to fitness
§ narrows the gene pool
Tuesday, March 6, 12
Honors Biology
Cheetahs
Tuesday, March 6, 12
Honors Biology
Cheetahs § All cheetahs share a small number of alleles
u less than 1% diversityu as if all cheetahs are
identical twins
Tuesday, March 6, 12
Honors Biology
Cheetahs § All cheetahs share a small number of alleles
u less than 1% diversityu as if all cheetahs are
identical twins§ 2 bottlenecks
u 10,000 years ago§ Ice Age
u last 100 years§ poaching & loss of habitat
Tuesday, March 6, 12
2011-2012Honors Biology
Tuesday, March 6, 12
2011-2012Honors Biology
Asking Questionsis a good adaptation!
Tuesday, March 6, 12