Vocabulary• Evolution is change over time.

• The naturalist Charles Darwin was the first person to write a thorough collection of evidence supporting evolution.

• Species a group of organisms that share traits AND can reproduce a fertile offspring.

5.1 Natural Selection

Darwin’s Claims• Darwin made observations about the diversity and uniqueness of organisms.

• He then made CLAIMS about the process responsible for this diversity.

• Darwin used all his years of observations as EVIDENCE to support these claims.

5.1 Natural Selection

Left - Voyage of the Beagle• Look at Figure 2 on pg 211.

• Where did the HMS Beagle stop before reaching the Galapagos Islands?

• Multiple locations on South America

Voyage of the Beagle

5.1 Natural Selection

Tortoises• Darwin found giant tortoises on all the Galapagos

Islands, but nowhere else.

• He wondered why they were so different even though they lived on islands only about 50 miles apart.

• He reasoned that each new population changed slightly, or evolved, to fit its unique environment on the island.

5.1 Natural Selection

LEFT- Tortoises• Read the first two paragraphs on pg 212. What is

unique about these tortoises?

5.1 Natural Selection

Dome-shaped Saddle-shaped

LEFT- Tortoises• Read the first two paragraphs on pg 212. What is

unique about these tortoises?

5.1 Natural Selection

Dome-shaped Saddle-shaped

Short necks Long necks

Eat low growing plants High growing catus.

LEFT- Tortoises• Why might one tortoise population evolve long necks?

• Share with your partner.

5.1 Natural Selection

RIGHT - Species

– Western spotted skunk,

– mountain lions

– great white sharks

– With your partner think of five other species, and write them down.

• Selective breeding is breeding plants and animals to get offspring with desired characteristics based on HUMAN needs only.

5.1 Natural Selection

Vocabulary

Not a Species– A mule is the offspring of a male donkey

and a female horse. Horses and donkeys are different species, with different numbers of chromosomes.

– A liger is the offspring of a male lion and a female tiger.

Liger in action

These are both examples of selective breeding, even if accidental.

LEFT - Not a Species

•Summarize what you learned about ligers!

•Now summarize what you learned today.