The Theory of Evolution & Natural Selection UNIT 7: Chapter 14-18

What is evolution? A change in species overtime.

The Horse Over 60 million years, the horse evolved from a dog-sized creature that lived in rainforests into an animal adapted to living on the plains and standing up to 2m high. In the process, its multi- toed feet, adapted for walking across the forest floor, evolved into single- toed hooves more suited for running over open country.

Charles Darwin Darwin was born in He sailed around the world (it took 5 years) He searched for scientific explanations for the diversity of life. Sailed on the HMS Beagle. He was a naturalist.

Charles Darwin’s Voyage

Charles Darwin Wrote a book on the Origin of Species Sailed with the HMS Beagle Observations made in the Galapagos Islands These observations helped him form the theory of how species change over time called natural selection

What did Darwin study? Finches Tortoises On the Galopagoes Island

What is Natural Selection? Natural selection is governed by the principles of genetics. Also known as “Survival of the Fittest”

Did the Biosphere adapt or evolve over time?

Pinta Island Intermediate shell Pinta Isabela Island Dome-shaped shell Hood Island Saddle-backed shell Hood Floreana Santa Fe Santa Cruz James Marchena Fernandina Isabela Tower Giant Tortoises of the Galápagos Islands Section 15-1

Evidence for Evolution 1.Fossil record 2.Anatomy Homologous structures Analagous structures 3.Vestigial structures 4.Embryology 5.Molecular biology (DNA differences)

Mechanism for change in a population of organisms: Animals who have greater fitness survive in environment and live to reproduce. Random changes in DNA (called mutation) can lead to greater or less fitness. Adaptations allow an organism to survive better in their environment.

Who’s More Fit….. Bear without clawsBear with claws

Adaptations large, flat feet, to spread their weight on the sand of their desert habitat thick fur on the top of the body for shade, and thin fur elsewhere to allow easy heat loss a large surface area to volume ratio, to maximise heat loss the ability to go for a long time without water (they don't store water in their humps, but they lose very little through urination and sweating) the ability to tolerate body temperatures up to 42°C slit-like nostrils, and two rows of eyelashes, to help prevent irritation from sand. a white appearance, as camouflage from prey on the snow and ice thick layers of fat and fur, for insulation against the cold a small surface area to volume ratio, to minimise heat loss a greasy coat, which sheds water after swimming

Japanese Spider Crab

Types of Adaptations Protective Coloring Camouflage Mimicry Physiological Adaptations Reproductive Changes Other changes Behavioral Adaptations

Peppered Moth Lab

DO NOW--- What are some similarities amongst these birds? Prehistoric BirdTurkey

Lamarck’s Theory of Evolution Section 15-2 LAMARCK PROPOSED THAT IF AN ORGANISM USED OR DIDN’T USE ORGANS (OR BODY PARTS) WOULD CAUSE IT TO CHANGE OVERTIME. His hypothesis was incorrect!!!

Jean-Baptist Lamarck French naturalist Born before Darwin First to form a hypothesis of evolution. He finally realized organisms adapt to their environment— don’t loss or gain traits from lack of using organs.

Adaptations Can arise in response to environmental pressures Temperature Antibiotic resistance in bacteria Pesticide resistance Morphological changes in peppered moths

Yellowstone Park Environment America’s first national park Variety of wildlife (grizzly bears, wolves, bison, elk) Preserved national park Located in Wyoming, Montana and Idaho Bacteria can survive in 400 degrees F. This is an example of adaptation. ermal_features/hot_springs.php

What is a Population? Populations are groups of interbreeding individuals that live in the same place at the same time. Populations evolve over many generations, individuals don’t! Individuals in a population compete for resources with each other.

How Does Evolution Work? Populations produce more offspring than the environment can support. The unequal ability of individuals to survive and reproduce leads to the gradual change in a population over many generations.

How are new species created? Geographic isolation Reproductive barriers Change in chromosome numbers Adaptive radiation

What is Extinction? The Dodo Bird

Review Evolution: 1.What is evolution? 2.What is natural selection? 3.Who was Charles Darwin? 4.What are 5 evidences that support evolution? 5.Describe a younger and older fossil and ground layers they would be fossilized in.

Answers 1.A change in species overtime. 2.Favorable variations that enables an organism to adapt successfully to a change in the environment. 3.He formed theory of evolution—species change overtime. 4.Fossil record, Anatomy, Vestigial structures, Embryology, Molecular biology 5.Younger layer would be in top ground sediment. Older layer would be below younger layer of fossil remains.