mrs. herman 2015 changes over time. evolution is the change over time in a population of related...
TRANSCRIPT
Mrs. Herman 2015
CHANGES OVER TIME
Evolution is the change over time in a population of related
organisms.
WHAT IS BIOLOGICAL EVOLUTION?
All living things have a common ancestor.
There are variations of individuals.Adaptations –(structural, behavioral,
functional).Organisms produce more offspring than
can survive.Competition exists among individuals.Natural selection.Artificial selection (selective breeding).
OVERVIEW OF THE THEORY OF EVOLUTION
Adapted from: Ms. Weinberg
toad
Animal Adaptations
Have you ever wondered how animals are able to survive in the wild?
Animals have certain adaptations that help them to survive.
Think about the way you dress in the winter.
You don’t wear your shorts and bathing suit when it’s snowing outside!
You wear warm clothes, and maybe
even a hat and mittens to protect yourself from the weather.
And what if you are having a snowball fight?
You probably run away from the person throwing at you,
and maybe even try to sneak up on that person and
throw some snowballs!
The way you dress in the winter, as well as the way that you run and hide from someone throwing snow at you
are kinds of …
Adaptations
An adaptation is an inherited trait that increases an organism’s change of surviving and reproducing in its environment.
We can separate adaptations into two
categories: Physical (structural and
functional)
AND
Behavioral
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Physical adaptations
are body structures that
allow an animal to find and consume food, defend itself,
and to reproduce its species.
Physical adaptations help an animal survive in its environment.
Hey! I’m a walking stick. I look just like a stick you’d find on the ground.
© A. Weinberg
Physical adaptationCamouflage (use of color in a
surrounding)
The chameleon can change its color to match its surroundings.
Mimicry (looking or sounding like another living
organism)The Viceroy butterfly uses mimicry to look like the
Monarch butterfly. Can you tell them apart?
Physical adaptation
I’m the Monarch!
I’m poisonous
I’m the Viceroy!
I’m not poisonous
Chemical defenses (like venom, ink, sprays)
Physical adaptation
Body coverings & parts (claws, beaks, feet, armor plates, skulls, teeth)
Physical adaptations
The elephant’s trunk is a physical adaptation that helps it to clean itself, eat, drink, and to pick things up.
Now let’s learn about
Behavioral Adaptations…
Behavioral Adaptations allow animals to respond to life needs.
Each organism has unique methods of adapting to its environment by means
of different actions.
Behavioral Adaptations
are animals’ actions.
We can divide Behavioral Adaptations into two groups:
Instinctive Learned
These behaviors happen naturally & don’t have to
be learned.
These behaviors must be taught.
Instinctive behaviors
happen naturally &
don’t need to be learned
=
Finding shelter
Methods of gathering & storing food
Defending oneself
Raising young
Hibernating
Migrating
Learned behaviors
Obtained by interacting with the environment and cannot be
passed on to the next generation
except by teaching.
=
language
Riding a bicycle
cooking
NATURAL SELECTION
Over time, natural selection
results in changes in inherited
characteristics of a population. These changes
increase a species fitness in its environment
The organisms whose variations best fit them to the environment are the ones who are most
likely to survive, reproduce and pass these desired variations on to the next generation.
(survival of the fittest)
CONCEPTS OF
NATURAL SELECTION
Competition exists among individuals for mates, territory and food.
CONCEPTS OF
NATURAL SELECTION
Organisms produce
more offspring than the
environment can
support because only a small
number will survive to adulthood.
CONCEPTS OF
NATURAL SELECTION
Variations exists among individuals within a species.
CONCEPTS OF
NATURAL SELECTION
ARTIFICIAL SELECTION (SELECTIVE BREEDING)
Selective breeding - process by which people choose which traits they would like to have in the next generation of offspring.
They then select the organisms, having those traits, to breed in order to produce offspring with those traits.
An example of this is breeding “teacup” dogs. Breeders cross
small dogs in an attempt to
produce offspring that are tiny.
EVIDENCE OF EVOLUTION
The Fossil Record
Geographic Distribution of Living Things
Homologous Body Structures
Similarities in Early Development
Vestigial organs
EVIDENCE OF EVOLUTION
The Fossil Record
Geographic Distribution of Living Things
Homologous Body Structures
Similarities in Early Development
Vestigial organs
EVIDENCE OF EVOLUTION
The Fossil RecordGeographic Distribution of Living Things
Homologous Body Structures - structures that have diff erent mature forms in diff erent organisms, but develop from the same embryonic tissue
Similarities in Early Development
Vestigial organs
EVIDENCE OF EVOLUTION
The Fossil Record
Geographic Distribution of Living Things
Homologous Body Structures
Similarities in Early Development
Vestigial organs
EVIDENCE OF EVOLUTION
The Fossil Record
Geographic Distribution of Living Things
Homologous Body Structures
Similarities in Early Development
Vestigial organs - organs that serve no useful function in an organism, i.e. appendix, tail bone.
Rib cage of a Python
Changes…..Environments are complex. Species must adapt to an
environment’s living parts as well as it’s nonliving parts. Nonliving parts include temperature, water, nutrients in soil
and climate. Deciduous trees shed their leaves due to changes in climate. Camouflage, mimicry and mouth shape are
adaptations mostly to an environments living parts.
Living and nonliving factors are always changing. Even slight environmental changes affect how species adapt. If a species is unable to adapt, it becomes extinct. The fossil record contains
many fossils of species that were unable to adapt to change.
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EVOLUTION OR EXTINCTION
Biological Evolution - the change over time
in populations of related organisms.
Extinction – occurs when the last individual organism of a
species dies.