Mr. Altorfer Science Change Over Time Pages 166 to 173

Objectives 1. Identify two kinds of evidence that show that organisms change over time. 1. Identify two kinds of evidence that show that organisms change over time. 2. Explain how comparing organisms can provide evidence that they have ancestors in common. 2. Explain how comparing organisms can provide evidence that they have ancestors in common.

Things change over time. Look at the evolution of the IPOD for example Things change over time. Look at the evolution of the IPOD for example

Evolution of the IPOD and People

Do Species Change Over Time? Evolution- The process in which populations (groups) gradually change over time. Evolution- The process in which populations (groups) gradually change over time. Charles Darwin is well known for his work on this topic. Charles Darwin is well known for his work on this topic.

Differences Among Organisms Adaptation- A characteristic that helps an organism survive and reproduce in its environment. Adaptation- A characteristic that helps an organism survive and reproduce in its environment. Adaptations may be physical characteristics or behaviors that help the organism survive. Adaptations may be physical characteristics or behaviors that help the organism survive.

Differences Among Organisms Examples of Physical Adaptations- Examples of Physical Adaptations- A giraffe’s long neck. How does a giraffe's long neck help it to survive? A giraffe’s long neck. How does a giraffe's long neck help it to survive?

Differences Among Organisms Examples of Physical Adaptations- Examples of Physical Adaptations- An elephants’ trunk. How does an elephant’s trunk help it to survive? An elephants’ trunk. How does an elephant’s trunk help it to survive?

Differences Among Organisms Examples of Physical Adaptations- Examples of Physical Adaptations- A person’s hands. How do our hands help us to survive? A person’s hands. How do our hands help us to survive?

Differences Among Organisms Examples of a behavioral adaptation. Examples of a behavioral adaptation. A bear hibernating. How does this behavior help the bear survive? A bear hibernating. How does this behavior help the bear survive?

Differences Among Organisms Species: A group of organisms that can mate with one another to produce fertile offspring. Species: A group of organisms that can mate with one another to produce fertile offspring. Population: Groups of individuals of the same species living in the same place. Population: Groups of individuals of the same species living in the same place.

Species American Bull Frogs Green Frogs These frogs are two different species of frogs!

Evidence of Changes Over Time Fossils- The remains or imprints of once-living organisms found in layers of rocks. Fossils- The remains or imprints of once-living organisms found in layers of rocks.

Comparing Organisms Common Ancestry- Evidence suggests that all living things have a common ancestor or relative. Common Ancestry- Evidence suggests that all living things have a common ancestor or relative. Example: People are very closely related to cats, dolphins and bats. Example: People are very closely related to cats, dolphins and bats.

Comparing Skeletal Structures Human Arm Cat Leg Dolphin Flipper Bat Wing

Bone Structure

Embryonic Development

Comparing DNA DNA Evidence- DNA Evidence that organisms are related to each other. DNA Evidence- DNA Evidence that organisms are related to each other. The more two organisms DNA matches, the more closely they are related to each other. The more two organisms DNA matches, the more closely they are related to each other.

Comparing DNA When human DNA is compared to chimpanzee DNA they are 98% similar! Wow!