Animals

Unit 3 – Different Kinds of Bodies

Content Learning Goal

• Students will learn how different animals breathe, eat and survive.

Language Learning Goal

Be able to define:

• Predator

• Prey

• Specialized

Different Ways to Breathe

• Animals have specialized parts to get oxygen

• Fish have gills• Land animals have lungs

Different Ways to Eat

• Mouths shapes are specialized to different animals

• Birds have beaks to reach insects in holes

• Dogs have long, sharp, pointed teeth to eat meat

• Horses have big, flat, wide teeth to grind up leaves and grass

Built to Get Food

• Animals that kill other animals for food are predators

• Animals killed by others are prey• Specialized Sense organs help animals see,

hear or smell prey

Built to Get Away

Animals have specialized body parts to keep them safe:

• Porcupine quills

• Turtle shells

• Mimicry – Moths – circles on their wings– Butterflies – change color– Lizards – Chameleons – Blend in/Camouflage

Make a poster

• In pairs, cut out a picture of an animal in a magazine and make a poster using the picture.

Note on the poster:• Note the specialized parts• How this animal breathes• How it’s mouth is shaped and what it eats• Write whether it is prey or a predator and what is

special about the animal to keep it safe• Note a few other animals that have the same

specialized parts

Charles Darwin

• Invented the Theory of Evolution

• He wrote a book called

“The Origin of Species”

• He didn’t believe in God or

“Creation”, so he wrote about

how he believed animals

must have come to exist

EvolutionThis theory says that all life came from one single cell that improved over long periods of time to finally make human beings

For example: Pond scum becomes a frog…a frog becomes a fish and a fish becomes a crocodile.

Evolution vs. Adaptation

• Evolution is the belief that non-living chemicals can organize themselves into a living thing that can reproduce itself

• Adaptation is a process that would remove defective organisms in order to conserve the health or safety of the population as a whole…this could be called “natural selection”

Evolution• The theory is: the first self-reproducing organism

would have made copies of itself. • There were likely errors or “mutations” in these

copies• Any mutations which enable an organism to make

more self-reproducing offspring would be passed on through new generations of different kinds of animals.

• This ‘differential reproduction’ is called natural selection (but is not to be confused with adaptation)

Adaptation

• Process animals go through to become more specialized to their environment

• This process only uses genes that an animal already has…it doesn’t ever develop anything new (so it is very different from Evolution)

• Let’s look at the following example…

Adaptation Example

These dogs have medium length hair, but have genes for short (s) and long (l) hair

If they breed, their offspring could get short, medium or long hair

Adaptation Example Cont.

• The dogs go through the “ice age” and none but the long haired dogs live because it is too cold

• Now all dogs on earth have long hair

Adaptation Example Cont

• They are now adapted to their environment.• They are now more specialized than their ancestors with

medium length hair.• This has occurred through natural selection.• There have been no new genes added.• In fact, genes have been lost from the population—there

has been a loss of genetic information, the opposite of what evolution teaches.

• Now the population is less able to adapt to future environmental changes—were the climate to become hot, there is no genetic information for short fur, so the dogs would probably overheat.

Evolution Example

• Often these are called “missing links”

• For example: in order for apes to evolve to humans, surely there would be some examples of living things that are in between monkeys and humans…but so far, no examples have been proven to be true…that is why they are termed “missing links”

Lucy

• A portion of an ape skeleton was found in 1974• Scientists around the world thought we had finally

found the “missing link” because they believed the skeleton appeared to have legs that walked upright

• It was later determined that this skeleton was only an extinct form of monkey most similar to a chimpanzee, and

• Lucy did not have a human-like “gait” or walk…she walked like an ape and used the knuckles on her hands to aid her in walking

Nebraska Man• A tooth was found in Nebraska in 1922 and believed to

be the long awaited proof of a missing link• This picture was drawn based on what scientists

believed the animal must have looked like…all based on finding one tooth

• 5 years later, more bones were found and it was determined that “Nebraska Man” was invented based on an extinct pig’s tooth

Journal

• Now get out a piece of paper

• Write your opinion on evolution and the origin of human beings. Where do you think we come from?

• Write one paragraph with at least three (3) sentences.