Mrs. Herman 2015 CHANGES OVER TIME. Evolution is the change over time in a population of related...

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

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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.

From text page 222

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.