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Chapter 11

Lesson 1 Evidence of Evolution What is evolution? Evolution is change over time.

The scientific theory of evolution explains howliving things descend from earlier organisms.

It helps us understand the history of life on Earth.

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What evidence supports evolution?

Fossils Similarities on DNA and protein structure

Similarities of body structure

Similarities in Early Development

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Fossils Fossils help scientist infer about the shape and

function of ancient organisms' body structures.

They support the theory that living organisms

evolved from earlier simpler organisms.

The Fossil Record (the millions of fossils collected

by scientists and organized by date) gives clues of

how and when a new species evolved and how

organisms may be related

Species a group of similar organisms that can mate

with each other and reproduce fertile offspring.

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Similarities in DNA and protein

Structure Scientists infer that species inherited many of

the same genes from a common ancestor.

The more similar the DNA sequence the moreclosely related the species are.

The order of amino acids in proteins can also

show how closely related two species may be.

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Similarities in Body Structures Organisms that share the same basic body

plan are assumed to have come from acommon ancestor.

Vertebrates have a backbone.

Invertebrates do not have a backbone.

Homologous structures structures shared by species are attributed to a

common ancestor.

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Similarities in early Development

Scientist also infer evolutionary relationshipsby comparing early development of organisms.

Organisms with common ancestry look similar

during the early stages of development.

(See next slide.)

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Lesson 2 Darwins Theory

Discovery Streaming

Natural Selection

The world of birds Eating like a bird

Gizmo Activities

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What is Natural Selection? Natural selection is the PROCESS by which

individuals that are better adapted to theenvironment are more likely to survive and

reproduce than other members of the same

specie. Adaptation - trait that increases the organisms

ability to survive and reproduce.

Variation - differences between individuals of

the same species.

Trait genetic characteristic.

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Environmental change + Adaptation = Natural

Selection.

The case of the Moth during the industrial

revolution.

The case of antibiotic resistant bacteria and super

bugs.

White Lizard

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Lesson 3 Biodiversity and

Extinction

How do new species form?

A new species can form when a group of

individuals remain isolated from the rest of its

species long enough to evolve different traitsthat prevent reproduction.

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What factors affect biodiversity? Biodiversity the number of different species in an area.

Factors that affect biodiversity in an ecosystem are as

follows:

Area the larger the area the more biodiversity.

Climate tropical rainforests are the most diverse

ecosystems.

Genetic Diversity species with diverse gene pools are

better able to adapt and survive. changes in theenvironment.

Niche Diversity a diverse habitat supports a larger

number of species than a uniformed habitat.

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Why do species go extinct?

Extinction when all members of a species

disappear on Earth.

Process of extinction Threaten species in danger to become endangered.

Endangered species in danger to become extinct.

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Extinction and Human Activities Extinction is a natural process that usually

happens gradually.

Extinction rates have increased do to human

activities.

Pollution

Contamination

Destruction of habitats Invasive species

Hunting