Adaptations

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What is Evolution?
The process of change in the traits of
populations over time.
Process by which species' characteristics change
over generations.
Traits must have genetic basis.
Evolution does not occur within an
individual. Evolution does not occur within a
generation.
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What is Evolution?
Evolution occurs primarily through natural
selection
Natural Selection is the process that determines
which individuals within a species will reproduce
and pass their genes to the next generation.
Proposed by Charles Darwin in his book On the
Origin of Species published in 1859
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Genes Distinct pieces of DNA that determine an
individuals characteristics.
PopulationAll organisms of the same kind found
within a specific geographic region. (have the
potential to interact)
Species Those organisms potentially capable of
reproducing naturally among themselves, and
producing viable offspring.
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Natural selection can occur when
Individuals within a species show genetically
determined variation in traits
-this variation makes some individuals better at
surviving and reproducing than others
More offspring are produced than survive to
reproduce
Offspring with a particular trait survive better
than do those without that trait
Over several generations, the frequency of that
trait increases in the population
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FLOW CHART FOR EVOLUTION
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Evolution in action
Pepper Moths in England
two forms light and dark
Prior to 1845, most moths light colored
Light colored ones could blend in with lichens on
trees
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Evolution in action
Pepper Moths in England
Increasing pollution led to soot-covered trees
without lichens
Light colored moths easy for birds to see on
soot-covered tree, dark colored moths harder to
see
By 1950, most moths black
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Before 1845
1950
Environment changes, now more black moths and
fewer white moths survive to adulthood
Several more generations later
Several generations later
Several more generations later
TIME
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Evolution in action
Resistance to herbicides
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Evolution in action
Resistance to antibiotics
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• Evolution does not just happen on long time scales

• Evolution is important for real-word issues
  agricultural, conservation, health

Disease dynamics
Invasive species issues
Antibiotic and pesticide/herbicide resistance
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Coevolution When two or more species interact
closely they can influence each others
evolutionary direction.
In tightly coevolved interactions, evolutionary
change in one species will lead to evolutionary
change in other or the second species may go
extinct.
Example host / parasite coevolution
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Abiotic Non-living factors Biotic living
portion of the environment
What are some biotic factors that contribute to
this differential survival and reproduction?
Interactions among organisms
1. Predation
2. Competition
3. Parasitism
4. Commensalism
5. Mutualism
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Interactions among organisms
1. Predation (positive for consumer, negative
for prey)
One animal consumes another
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Types of predators
Active predators chase overpower prey
Sit-and-wait predators motionless until prey
close enough to strike
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Sit-and-wait predator
Antlion
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HOW DO VULNERABLE ORGANISMS PROTECT THEMSELVES?
The bombardier beetle
The best defense is a good offense - chemical
warfare
A monarch caterpillar
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Many prey items have traits that reduce predation
Cryptic Coloration blend in with environment
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A moth
The leafy sea dragon
A desert plant
Florida treehopper insects
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Warning or aposematic coloration
The South American poison arrow frog
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Many prey items have traits that reduce predation
Warning Coloration aposematic coloration -
conspicuous to convey threat
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Startle coloration
caterpillar larva of the swallowtail butterfly
the false-eyed frog
The peacock moth
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ADAPTIVE COLORATION AND MIMICRY

• Types of Mimicry
• 1. Batesian mimicry mimic species resemble an
  unplatable or venomous species (the model)
• 2. Mullerian mimicry all mimic species have
  similar warning coloration. All mimics are
  usually toxic or harmful and function as both
  model and mimic.

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Batesian Mimicry defenseless species (mimic) is
protected from predation by its resemblance to a
species that is dangerous (the model) Henry
Walter Bates was an English biologist who
described a type of mimicry in tropical
butterflies in the 1850's.
fly (bee mimic)
bumble bee
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mountain king snake
coral snake
viceroy
monarch butterfly
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Naïve Blue Jay and a Monarch Butterfly
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Batesian Mimicry in Plants Stinging Nettle
(model) and the Yellow Archangel (the mimic)
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Visual and behavioral mimicry
the snowberry fly
a jumping spider
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Mullerian Mimicry Two or more distasteful or
harmful organisms resemble each other each serve
as model and mimic. Fritz Muller was a German
zoologist who described a different type of
mimicry in 1878.
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Interactions among organisms
1. Predation
Predator benefits () from food
Prey is harmed (-) by being eaten
Predation is a ( / - ) relationship
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Interactions among organisms
2. Competition
Competition organisms compete for the same
limited resource Ex. light, food, mates,
habitat, etc.
Competition is a (- / - ) relationship
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Intraspecific competition Members of same
species competing for resources
Beetle vs. Beetle
Fungus vs. Fungus
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Interspecific competition Members of different
species competing for resources May lead to
competitive exclusion
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Interactions among organisms
3. Parasitism One organism (parasite) living in
or on another organism (host), from which it
derives nourishment
Ex. Tapeworm
Parasitism is a ( / - ) relationship
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3. Parasitism (,-)
EctoparasitesLive on hosts surface (e.g.,
Fleas, lice, some molds)
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3. Parasitism (,-)
EndoparasitesLive inside host. (e.g., worms,
protozoa, bacteria, fungi)
Ex. Heartworm
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Parasitoid
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Nest Parasitism
Adult cowbirds dont build nests
Cowbird
Common Yellow-throat
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Vectors animals that carry parasite from one
host to another
Examples Malaria, Lyme Disease, West Nile Virus,
Bubonic Plague
Malaria carrying mosquito
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Interactions among organisms
4. Commensalism One organism benefits, while
the other is unaffected.
Remora and shark
Commensalism is a ( / 0 ) relationship
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4. Commensalism (,-)
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Interactions among organisms
5. Mutualism - Both species benefit.
Acacia and ants
Tree provides sugar solution that the ants
eats Ants defends tree against grazers
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5. Mutualism (,)
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Summary of 5 major Interactions
Individual 1 Individual 2
Predation - Competition - - Parasitism
- Commensalism Neutral Mutualism

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How have people change these interactions?
1) Introduced species
2) Habitat destruction
Introduction of novel predators and parasites can
devastate natural communities.
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Over 2,000 species of birds have gone extinct on
islands as a result of habitat loss and the
introduction of predators and parasites.
Hawaii Habitat loss, malaria, rats and mongoose
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Points to know

• Know what evolution is and how is operates.
  Understand coevolution.
• Know the 5 main types of species interactions.
• Understand who benefits from each type of
  interaction (one or both participants)
• Understand how humans may influence these
  interactions.

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On-Line Sources of Information used to create
this presentation

• http//www.uta.edu/biology/alie/1282/Lecture2.ppt
  260,6,SUMMARY OF EVOLUTION
• http//www.life.uiuc.edu/ib/105/lectures/06_EcolIn
  ter.ppt429,1,Slide