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Ch. 3 Adapting to
the Environment
Ch. 4 Population
Changes

Species  a group of
organisms with similar
characteristics that can
reproduce among themselves

Group of individuals of the
same species living in the same
place make up a Population
Why do animals look different
in different environments?
Arctic Fox
Desert Fox
Kangaroo Rat
• Lives in dry climates
• Feeds on seeds
• Access to very little water
Lab Rat
• Lives in controlled
environment
• Feeds on Rat Chow
• Unlimited access to water
Hypothesis: Why do we observe these variations in rat species in different
environments?
Prediction: What adaptations do these animals have?
Reproduction

For a species to survive, some
members of a species must
reproduce
2
Methods of Reproduction:
1.Asexual Reproduction
2.Sexual Reproduction
Asexual Reproduction
Single parent has offspring that
are genetically identical to parent
 Advantage – 1. Requires No Mate
2. Lots offspring in a short
amount of time

 Disadvantage
– All look same
Asexual Reproduction

Number one form reproduction
on planet (Bacteria)
 Examples
:
a. Budding (Hydra)
b. Fragmentation (Sea Star)
c. Binary Fission (Bacteria)


Sexual Reproduction
Offspring are formed when genetic
information from more than one
parent combines
 Advantage – Greater Variation
 Animals: 2 Parents
Female – Egg
Male – Sperm
Fertilization  joining of egg and
sperm

Types of Fertilization
1. External – parents have no
contact
-- Need Water (Fish, Frogs)
2. Internal – parents have
contact
-- Mammals, Birds, Reptiles

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Genetic information is found on Genes
Genes are located on Chromosomes
(made of Protein and DNA)
Offspring (children)
Variation  is an advantage /
disadvantage of sexual reproduction and
occurs in both plants and animals
-- this will help an organism survive or
go extinct

Plant Reproduction

Like animals, plants can
reproduce either asexually or
sexually. Some plants can
even use both methods. The
way a type of plant reproduces
is dependent on the plant’s
environment.
Plant Reproduction
NonVascular Plants (Asexual)
 Involves Spores (carried Wind/Water/
Animal)
 Produced Large Numbers
 Advantage – The greater number of
spores (cell) or sporophyte produced, the
greater chance they grow into
gametophyte (sperm or egg)
 Examples – Mosses, Liverworts,
Hornworts

Plant Reproduction
Vascular Plants (Sexual)
 Pollination  wind transfers pollen
from the male cone to the female cone
2 Types
1. Gymnosperms -- no flowers or
fruit
2. Angiosperms -- has flowers or fruit
Animal Behavior

Animals run from enemies,
search for food, battle for
territory, and build homes. All of
these activities are known as
Behavior.
2 Kinds of Behavior :
Innate Behavior


An inherited behavior (genes) that
does not depend on the environment.
(present at birth or show up months /
years later)
Examples : Puppies – Chew, Bees –
Fly, Whales – Swim, Humans – Walk
Learned Behavior

Behavior that has been learned
from experience or from
observing other animals

Example: Language (we have
the ability, we do not know the
meanings)
Survival Behaviors
Find Food a. Predator (eat other
animals) b. Prey (animals being
eaten)
2. Marking Territory -- area
occupied by one animal or group of
animals that do not allow other
members of the species to enter
(Mating, Raising Young, Find Food)
1.
Survival Behaviors
Defensive Action – allows animals to
protect resources from other animals
(skunk, squid, jellyfish)
4. Courtship – need to find mate to
reproduce (dance, build nest, fight)
5. Parenting – some offspring need help
for survival, while others do not
(caterpillar, birds, human)
3.
Seasonal Behavior
Migration – animals travel warm
environment (food, water, reproduction)
2. Slow Down – save energy
a. Hibernation – Winter (Bear)
b. Estivation – Summer (Desert animals)
3. Biological Clock – animals keep track
of time so they know when to store
food, or migrate (length day or temp.)
1.
Evolution
the changes in inherited
characteristics of a
species over time.
--As the environment
changes, so does the
organisms that live in the
environment

1) Mutation
2) Natural
Selection
(Survival of Fittest)
3) Gene Flow (individuals
migrate from place to
place)
4) Genetic Drift (individuals
leave and are isolated)
Theories
How Species
Change Over Time
Charles Darwin
December 27, 1831
 HMS Beagle
 Naturalist
 Galapagos Islands
(Finches and Tortoises)

Bird Beak Adaptations:
Theory

Suggested that random
variations takes place in living
things and some external
agent in the environment
selects those individuals better
able to survive.
Book “The Origin of
Species”
 Members of a large population
compete for living space, food,
and other resources. Those
that are able to survive will
reproduce and pass their traits
to the next generation.

Darwin’s theory of
Evolution is accepted by
most scientists today.
Known as Natural
Selection (Survival of
Fittest)

Natural Selection
Organisms must be able to:
1.Find Food / Water
2.Have Shelter
3.Reproduce
-- > If an organisms is missing one
of the three characteristics the
organism will go Extinct

4 Parts of Natural Selection
Overproduction
2. Genetic Variation with a
Population
3. Struggle to Survive
4. Successful Reproduction
Examples: Rabbit, Tarantula
1.

Variation  inherited traits
that make an organism
different from other members
of its species.
Example–
(England)
Peppered Moth
Adaptation

Variation or characteristic that
improves an organisms ability to
survive and reproduce in an
environment
 The
variation that result in an
adaptation can involve an organisms:
1) Color
2) Shape
3) Behavior
4) Chemical
Make-Up
5) Camouflage (blending
environment)
6) Mimicry (falsely resemble
other species)
Adaptations to Interactions
with other Organisms
Species adapt to interact with
one another in order to survive
 Example : Honeycreeper (Bird)
Lobelia (Flower)

Changes in Genetic Variation


Genetic Bottleneck – if a
population is decreased rapidly, many
characteristics may be lost entirely
from a population because all of the
individuals with those characteristics
dies
Example: Florida Panther
Figure 23.5 The bottleneck effect: an analogy

Geographic Isolation
 sometimes mountains,
lakes, or other geologic
features isolate a small
number of individuals
from the rest of a
population.

Ideas about Breeding
Plants and Animals have been
breed for years to pass on desired
traits
 Selective Breeding – human
practice of breeding Animals /
Plants that have certain traits
 Example: More than 150 species
Dogs

Speed of
Evolution
(2 Kinds)
Gradualism


Describes evolution as a slow,
ongoing process.
Darwin’s Theory------ use
Fossil Record
Punctuated Equilibrium

Gene mutation can result in
a new species in a short
amount of time.
Can be seen today
(Bacteria).

Fossils Found in
Sedimentary Rock show
evidence that living things
evolved.

Paleontologist  a
scientist who studies fossils.

Two Methods To
Determine Fossil
Age

Relative Dating 
look at fossil location in a
particular layer of rock;
older rock layers are
under newer rock layers.


Radiometric Dating
 compare the amount
of radioactive element
with the amount of
nonradioactive element
in a rock.

The Fossil Records
have gaps because
most organisms do
not become fossils.
More Clues
About Evolution
Direct Evidence

Such as the development of
Antibiotic Resistance in bacteria,
supports evolution.
Insecticide Resistance – insects
immune to pesticides
Example – European Corn Borer

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Homologous Structure
body parts that are similar
in origin and structure.
Examples--- Human Arm,
Bat, Whale
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Vestigial Structure
structure that don’t seem to
have a function but might
have once functioned in an
ancestor.
Examples---(HumanAppendix)
DNA

Best way to see how
close organisms are
related.