HAPPY THURSDAY Bellwork: How many bright stars do you see on each square? Black stars on each square? What is this an example of?

Peppered moths are eaten by birds. The moth color varies from light to dark. Light colored moths can blend in with a nearby species of tree. In the 1800s factories released large amounts of soot, which changed the tree color, so the birds were able to more easily find the lighter moths instead of the darker moths.

Standard: (7E)Analyze and evaluate relationship of natural

selection to adaptation.

Essential Question: What is evolution?

Quiz tomorrow – Vocabulary and

Notes

HW: Evolution Practice

Search for the YouTube video “Evolution Practice”by Alyssa Dolny.

PreAP: Complete on Page 42 of your I.A.N. using Cornell Notes. Due on Friday.

Periods 4 & 5: Complete on Page 45 of your I.A.N. using Cornell Notes. Due on Friday.

Summary of Darwin’s Theory: Individual organisms differ and some of these variations are

heritable (passed on) Organisms produce more offspring than can survive and

many that do survive do not reproduce Because more organisms are produce than can survive, they

must compete for limited resources (food, shelter, etc) Each unique organism has different advantages (good) and

disadvantages (bad) Individuals best suited to their environment survive and

reproduce successfully These organisms that survive pass their heritable traits to

their offspring

Summary of Darwin’s Theory cont’d: Other individuals that are not suited for their

environment die or leave few offspring This process called natural selection causes species

to change over time Species alive today are descended with modification

from ancestral species (their ancestors) This process by which diverse species evolved from

a common ancestor unites all organisms on Earth into a single tree of life

One of Darwin’s most important insights was that members of each species vary from one another in important

ways.

Today, we know that heritable variation in

organisms is caused by variations in their genes.

II. How Evolution Works

A. Artificial selection: selection by humans for breeding of useful traits

1. The struggle for existence is competition among

members of a species for food, living space, and the other necessities of life.

2. High birth rates and a shortage of life’s basic needs eventually forces organisms into a competition for resources.

B. Fitness: the ability of an organism to survive and reproduce

1. Fitness is the result of adaptations.

2. Adaptation: any inherited characteristic that increases an organism’s chance of survival.

a. Successful adaptations: - enable organisms to become better suited to

their environment - increase an individual’s ability to survive and

reproduce.

Humans have thousands of adaptations: large brain, opposable thumbs, excellent sensory organs, light, strong skeleton, etc.

C. Natural selection: the process by which individuals with characteristics that are not well suited to their

environment either die or leave few offspring.

1. Also referred to as survival of the fittest.

2. It is not seen directly, but only observed as changes in a population over a long time.

3. Zombieland: The Rules

A. Descent with modification: a principle that says each living species has descended, with changes, from other species over time.

1. It implies that all living organisms are related

2. Also known as common descent.

3. States all species were derived from common ancestors.

B. Darwin found evidence in:1. the fossil record2. the geographical distribution of living species (Biogeography)3. homologous structures of living organisms4. similarities in early development, or embryology.

C. Scientists use the fossil record to help determine evolutionary changes.

By comparing fossils from older rock layers with fossils from younger layers, scientists could document the fact that life on Earth has changed over time.Researchers have discovered many hundreds of transitional fossils that document various intermediate stages in the evolution of modern species from organisms that are now extinct.

Gaps remain in the fossil record. These gaps do not indicate weaknesses in the theory of evolution itself.

Rather, they point out uncertainties in our understanding of exactly how some species evolved.

D. Homologous structures: structures that have different mature forms but develop from the same embryonic tissues

are called (start different, end similar)

E. Vestigial organs are organs that serve no useful function in an organism.

Something Important to Know:

Theory: a well-supported scientific explanation that is subject to change.

Law: a scientific fact.

Evolution is a theory.

Evolution is often called “the grand unifying theory of biology.”

Evolutionary theory continues to change as new data are gathered and new ways of thinking arise.