HW # 83- Vocabulary Booklet (due Friday) HW TOC will be collected FRIDAY 3/15 Complete your notes.

Warm up

What is the significance of “pie/ π” day?

Week 25, Day Three

Warm up Response

Pi is a name given to the ratio of the circumference of a circle to the diameter

Explained on You tube

Homework Response/Check• Did you work on your vocabulary booklet?

Goals for Today

• Evolution Notes

Evolution Notes

Part 1

Charles Darwin

• Born in England• Traveled around on

HMS Beagle - Set Sail in 1831

• Collected many specimens

• Father of the idea of Evolution

Voyage of The Beagle

Darwin & The Galapagos

• Galapagos Islands are a small group of islands 1000km west of South America

• Studied Tortoises and Finches on the islands.

• Used geography of islands and differentiation of species to figure out evolution

Galapagos Islands

Galapagos Islands

• Although they were close together, the islands had very different climates.

• The smallest, lowest islands were hot, dry, and nearly barren.– Hood Island - sparse vegetation.

• The higher islands had greater rainfall and a different assortment of plants and animals.– Isabela Island - rich vegetation

• Allowed for different species of the same animal --> formed through evolution!

Galapagos Finches

Galapagos Finches

Galapagos Tortoises

Galapagos Blue-Footed Booby

• Male dances and shows its feet to the female to attract her

• Female chooses male with brightest feet and best dance

• Sexual selection!• Sexual selection is a trait

or behavior that acts on an organism's ability to obtain a mate

Darwin’s Thoughts

• On his travel home, he began to think of his observations.

• He found…characteristics of many animals and plants varied noticeably among the different islands of the Galapagos

• According to this hypothesis, these separate species would have evolved from an original South American ancestor species after becoming isolated from one another

Inherited Variation and Natural Selection

• Darwin noted that plant and animal breeders used heritable variation, what we now call genetic variation, to improve crops and livestock.

• Artificial selection: nature provided the variation, and humans selected those variations that they found useful.– A.K.A Selective Breeding

Better Picture of Artificial Selection

Natural Selection

• Each organism has different advantages and disadvantages– Individual best suited for environment survive and

REPRODUCE– Pass these traits onto offspring, and they are more

able to survive and reproduce• Occurs only when a few survive• Remember: differences (genes) in offspring

occur at random!

Darwin’s Concept of Evolution

• Biggest contribution is his idea of the mechanism behind Evolution– The Struggle for Existence– Survival of the Fittest– Descent with Modification

Struggle For Existence

• Struggle for existence: means that members of each species compete regularly to obtain food, living space, and other necessities of life.– Predators that are faster win– Prey that are better camouflaged or protected

win

Survival of the Fittest

• Fitness: ability of an individual to survive and reproduce in its specific environment.– Result of adaptations

• Adaptation: any inherited characteristic that increases an organisms chance of survival

Survival of the Fittest

• Survival of the Fittest: the idea that individuals that are better suited to their environment survive and reproduce more successfully– A.K.A. Natural

selection

Descent with Modification• Natural selection

produces organisms that have different structures

• Descent with modification: each living species has descended, with changes, from other species over time