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Unit Notes:

This unit will correspond to Unit 5 in your Textbook (pp. 366-467)
Chapter 15 – Darwin's Theory of Evolution
Chapter 17 – The History of Life
Chapter 18 - Classification

Khan Academy Introduction to Unit

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Darwin’s Theory of Evolution

Evolution means simply “change over time”
Observed evidence confirms that modern day organisms have descended from more ancient ancestors with modifications
The scientific theory of evolution is an explanation for why things change over time
This theory has greater support due to intense scrutiny and investigation than either atomic or gravity theories.

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The Travels of Charles Darwin

During his travels along the H.M.S. Beagle, Darwin made many observations and collected evidence from both living species and __________.
This led him to propose a hypothesis about the mechanism behind how life changes over time
Darwin observed that the characteristics of many animals and plants varied noticeably as he went from island to island in the Galapagos

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Q: Describe Darwin's Journey on the Beagle

Figure 15-1 (p.369)

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Darwin’s Observations:�Patterns of Diversity

During 1 day in the Brazilian rainforest, Darwin identified 68 different beetle species; he wasn’t looking for beetles
Darwin began to realize the magnitude of biodiversity on earth
Darwin found that animals are remarkably well suited to their ___________, sharing advantageous characteristics that allowed different species to survive and thrive
Europe held surprisingly similar grassland ecosystems of Argentina or Australia, however the organisms found in the grasslands differed greatly�
Challenge Question:

why no rabbits in Australia? Why no Kangaroos in England?

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Darwin’s Observations:�Living Organisms and Fossils

Living organisms are only a piece of the puzzle; Darwin also collected the ancient remains of long dead organisms, called fossils
Some fossils resembled those of living species, others looked like no other species ever observed
Questions that arose included:

Why do species disappear?
How are they related to living species?

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Darwin’s Observations:�The Galapagos Islands

The most influential of all Darwin’s travels were the Galapagos Islands
Although close together, each island had a unique climate
Hood (smallest and lowest) was hot, dry and barren

Very sparse vegetation

The Higher the altitude of the island, the greater the rainfall and as a result, the greater the amount of vegetation and animal-life
Certain animals, such as the Giant Tortoise, varied predictably from island-to-island

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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

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Darwin’s Theory - Summarized

Individual organisms _________; some of this variation is heritable (can be passed on to offspring)

Look around the classroom, what traits vary from person to person?

Organisms _________ more offspring than can survive, and many that do survive do not reproduce

Some organisms never reach maturity due to starvation or predation for example; many of those that do survive are often sickly or not healthy enough to reproduce

Because more organisms are produced than can survive, they compete for limited _______________

The organisms best able to find and use resources are more likely to survive and reproduce.

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Each organisms has different advantages and disadvantages in the struggle for existence. Individuals _____ suited to their environment survive and reproduce most successfully. These organisms pass on their heritable traits to their offspring. This process of natural selection causes species to change over time.

The environment dictates who survives, and does not always correspond to the fastest or strongest.

Species alive today are __________ with __________ from ancestral species that lived in the distant past. This process by which diverse species evolved from common ancestors, unites all organisms on earth into a single ‘tree of life’

All organisms share certain characteristics in common

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Assignment

Survival of the Sneakiest

Read the hand-out and complete the questions at its conclusion in your notebook on a new piece of loose leaf. Hand in by the end of class.

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Like any theory, evolutionary theory continues to change as new data comes to light
Evolutionary theory provides vital insights to ecological and medical problems, giving us the expertise to understand and prevent harmful changes in our environment
Questions still remain:

How do new species arise?
Why do species go extinct?
How did life begin?

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Ideas that Shaped Darwin's Thinking

During Darwin’s era, the scientific world was coming to terms with both:

Geologist James Hutton’s 1795 assertion that the world was more than thousands of years old, but rather millions was critical to Darwin’s theory (small changes accumulating over vast periods of time)
Charles Lyell’s assertion that scientists can only explain past events in terms of processes that they can observe currently, as the processes that shape our world today indeed shaped the ancient world as well supported Darwin’s theory (mechanism for change is the same now as in the past)

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Jean-Babtiste Lamarck was the first scientist to put forward the idea that living things change over time; his explanation stated:
By selective use and disuse of organs, organisms acquired or lost certain characteristics in their lifetime
These traits were passed on to offspring and over time this process led to considerable change in the overall species

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Lamarckian evolution includes:
Tendency towards perfection

An innate (built-in) tendency exists within organisms toward complexity and perfection

Use and Disuse

Can alter the size or shape of their body in new ways (i.e. work out and become stronger; a bird that refuses to fly would lose its wings over time)

Inheritance of Acquired Traits

If during its lifetime, an organisms grew longer legs or fluffier feathers, it would pass that trait on to its offspring

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Lamarckian Evolutionary Theory

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Lamarck was incorrect in several ways, namely that an organisms behavior has no impact on its heritable characteristics

Ex. if you lose your hands in an accident, your child will be born with both hands

Lamarck was revolutionary for his time however, as he put forward the idea that organisms adapt to their environment, paving the way for Darwin and other scientists

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How are Lamarck and Darwin Different?

Lamarck suggested that organisms choose their characteristics
Darwin suggested that natural variation exists
Lamarck suggested that organisms evolve to become ‘perfect’
Darwin put forward that evolution occurs only in response to a change in the environment; i.e. nature selects which organisms are best suited to survive.

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Thomas Malthus is often associated with ‘doomsday’ whereby the human species would collapse; people that believe mankind is due for a collapse are often called Malthusian
Malthus believed that if the human population continued to grow unchecked, sooner or later there would be insufficient space and food for everyone
Darwin supposed that this tendency was more applicable to plants and animals, as they produce more offspring than are capable of survival (i.e. 1 oyster can produce 1 million eggs per year; only a small fraction will survive)
Q: What factors determine which offspring are capable of survival and reproduction?

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Research Assignment

The question is often asked: “Why are we learning this? How is it relevant to my life?”
You have received a handout titled “Relevance of Evolution”; this assignment has been divided into four main areas, you will be responsible for only the on specified on your assignment hand-out:

Agriculture
Medicine
Conservation
Co-evolution of Species

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Due Date:
Ideas for an open Media Rubric:

Essay
Poster
Pamphlet
Video
Webpage

Use the class-time provided (Monday-Wednesday) to navigate the website, record key questions and record some notes that will help answer each key question
Before beginning your project, carefully read through the evaluation rubric and ask any questions before you begin

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Video Assignment

Watch each video segment
following a quick class discussion, answer each question with as much detail as possible.
Q: What is wrong with the statement: “Evolution is just a theory”?
Q: Who Was Charles Darwin?
Q: How do we know evolution happens?
Q: How does evolution really work?
Q: How did humans evolve?
Q: Why does evolution matter now?
Optional Question:

Q: Why is evolution controversial anyway?

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Quick Assignment�Evolutionary Classification

Construct a table that has five columns and six rows.

In the columns, write the following heads: Animal Group, Example, Legs, Fins, and Tail.
Place the following animal groups in their own row: Mammal, Bird, Fish, Amphibian, Reptile, and Insect.

Give one example for each group, and then fill in the information for that example. For Legs, write in the number of legs that each animal has. Do animals with fins have legs? Do animals with wings have legs? If so, how many?
Can you tell from your table if a fish is more closely related to a bird or to an amphibian? Explain your answer.
Cosmos: with Carl Sagan - Evolution

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Beaver

Muskrat

Beaver and�Muskrat

Coypu

Capybara

Coypu and�Capybara

What does the following picture illustrate about the distribution of similar species? �
Do you believe these organisms are closely related? Why?�
Which animal has a larger geographical range, the coypu or the muskrat? Which do you think is more specialized to their respective habitat?

Figure 15-14 (p.383)

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Homologous structures (fig. 15-15, p.384)

Turtle

Alligator

Bird

Mammal

Ancient lobe-finned fish

Homologous structures are one type of evidence for the evolution of living things.

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Practical Applications of Darwin’s Theory

Prior to Darwin, variation among species was seen as an unimportant, minor defect
In artificial selection, nature provides the variation in a species, and humans select those variations found useful
Artificial selection has given rise many domestic plants and animals by selectively breeding for different traits.
Meet the Super-cow

Warning: some images of artificial insemination may be too graphic for some students; please put your head down if you do not wish to watch

Optional Video: Samurai Faced Crab

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Chapter 15 - Assignment

15-1 (p.372)

Focus on the Big Idea

15-2 (p.377)

15-3 (p.386)

#2, 3

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Exploration:�Modeling Adaptation

Complete the activity as described on p.387
Complete 3 Rounds of this activity with your partner, recording your data each time (what was role, your habitat, your score, the result)
Your write-up must include:

Name, Date, Title, Partners
Sections: Problem, Materials, Procedure, Data, Analysis/Conclusion (questions)

Complete the “Go Further” activity (time permitting)

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Icons of Science - Evolution

During the course of this video, record some brief notes from each section that seem significant or are of interest
These notes will be part of a notebook check at a later date.

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Unit 2 - Quiz #1

Evolution by Natural Selection

includes all content from beginning of this section.

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The History of Life

The fossil record provides evidence about the history of life on earth, it reveals how different groups of organisms have changed over time
There are two ways to date fossil evidence:
Relative Dating: Dating a fossil relative to the proximity to different types of sedimentary rock and other fossils
Radioactive Dating: Calculate the absolute age (in years) of a fossil based on the remaining isotopes contained within
Video

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Comparing Relative and Absolute Dating of Fossils

Relative Dating

Absolute Dating

Can determine

Age of fossil with respect to another rock or fossil (that is, older or younger)

Age of a fossil in years

Is performed by

Comparing depth of a fossil’s source rock stratum to the position of a reference fossil or rock

Determining the relative amounts of a radioactive isotope and nonradioactive isotope in a specimen

Drawbacks

Imprecision and limitations of age data

Difficulty of radioassay laboratory methods

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How Do Fossils Form?

Water carries small rock particles to lakes and seas.

Dead organisms are buried by layers of sediment, which forms new rock.

The preserved remains may later be discovered and studied.

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Fossil Formation Activity (optional)

Receive Answer Sheet; complete while we navigate online
Web-link

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Mystery Detective

Earth is billions of years old. There were not any witnesses to those early years. How, then, can scientists determine the conditions on Earth long before there were any scientists?
Think about how you draw conclusions about occurrences that you did not witness. If you saw the charred remains of a house, for example, you could infer that it burned down.
List things that you can observe around you that lead you to infer about events you did not see. (For example, what do skid marks in the roadway tell you?)
Now, think about and list the evidence all around you that scientists might analyze when trying to piece together a history of Earth. How would finding the fossil of a sea animal in the middle of a desert tell a scientist something about the past?

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Evolution of Life – A Concept Map

Early Earth was hot; atmosphere contained poisonous gases.

Earth cooled and oceans condensed.

Simple organic molecules may have formed in the oceans..

Small sequences of RNA may have formed and replicated.

First prokaryotes may have formed when RNA or DNA was enclosed in microspheres.

Later prokaryotes were photosynthetic and produced oxygen.

An oxygenated atmosphere capped by the ozone layer protected Earth.

First eukaryotes may have been communities of prokaryotes.

Multicellular eukaryotes evolved.

Sexual reproduction increased genetic variability, hastening evolution.

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�The Miller- Urey Experiment�Video #2 - Sagan Cosmos

Mixture of gases simulating atmospheres of early Earth

Spark simulating lightning storms

Condensation chamber

Cold water cools chamber, causing droplets to form

Water vapor

Liquid containing amino acids and other organic compounds

Q: Describe the Miller-Urey Experiment in your own words.

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Origin of Complex Life – Endosymbiotic Theory

Aerobic bacteria

Ancient Prokaryotes

Ancient Anaerobic Prokaryote

Primitive Aerobic Eukaryote

Primitive Photosynthetic Eukaryote

Chloroplast

Photosynthetic bacteria

Nuclear envelope evolving

Mitochondrion

Plants and plantlike protists

Animals, fungi, and non-plantlike protists

Video

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Patterns of Evolution

Macroevolution are the large scale patterns and processes that occur over long periods of time. The 6 major topics are:
Extinction
Adaptive Radiation
Convergent Evolution
Co-evolution
Punctuated Equilibrium
Changes in developmental Genes

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Chapter 17 - Assignment

17-1 (p.422)

#3, 5

17-2 (p.428)

#1-4

17-4 (p.440)

#1-3, Thinking Visually

Research Assignment

define the 6 major patterns of evolution, providing an example of each

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Analyzing Data�Changing Number of Marine Families

Complete Activity on p.438 on separate piece of paper
Due Date: Today, end of class

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Taxonomy

Evolution is the process by which new organisms come to be; natural selection is the mechanism behind it.
To study the diversity of _____, we must develop a classification system to name organisms and group them appropriately
This discipline is called _______________
Web-activity Sample

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To avoid confusion caused by regional names, the taxonomic system must be universal across borders and languages.

i.e. a Cow, Vache, Krava, Waka, Ushi are all names for the same organism; the taxonomic name bos primegenius is universal in all languages and countries

Q: What Canadian animal has more than one common name?

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Answer

sample answer: Mountain Lion, Puma, Cougar, Panther all represent the same animal, Felis concolor

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Binomial Nomenclature

Each species is assigned a ____ part name; the name is written in italics, the first word is capitalized, the second word is not.
The first name corresponds to the genus, which represents a group of closely related organisms
The second name corresponds to the ______

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Carolus Linnaeus was a swedish botanist, who developed a system that became the forerunner to the modern taxonomic system
Each level of this system is called a taxon

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Linnaeus’s System of Classification

Phylum

Class

Order

Family

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The system is organized from the general to the specific

Grizzly bear

Black bear

Giant panda

Red fox

Abert squirrel

Coral snake

Sea star

KINGDOM Animalia

PHYLUM Chordata

CLASS Mammalia

ORDER Carnivora

FAMILY Ursidae

GENUS Ursus

SPECIES Ursus arctos

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Kingdom

The _________ and most ________taxon; separates organisms on a very basic and elementary level
Linnaeus originally recognized only two kingdoms
Plantae
Animalia
In years to come, new kingdoms would be created to classify microorganisms like _________, _________ and __________

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Phylum

The 2nd largest group, separates organisms by a more specific characteristic
Consists of a group of similar classes of organisms
i.e. Phylum Chordata consists of all organisms with a spinal chord
These organisms share many aspects of their body plan and internal functions in common

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Class

The 3rd largest group, even more specific characteristics are used to differentiate these organisms
Made up of similar __________ of organisms
i.e. Class Mammalia contains all organisms that are warm blooded, have body hair and produce milk for their offspring

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Order

Broad category composed of similar families
i.e. the Order Carnivora contains many organisms with similar characteristics
Q: What characteristics might they share?

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Family

A specific group of organisms that share a great deal of characteristics with one another
Composed of similar __________
i.e. The Family Ursidae is composed of all existing bear species

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Genus

Small Group of very similar organisms
Composed of similar species
The Genus Ursus includes the grizzly and polar bear; the panda is in a separate genus called Ailuropoda

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Species

Often a Latinized description of a unique characteristic or native location of the organism
i.e. Ursus Maritimus would refer to a bear that lives near the sea or on floating ice pack, in this case a polar bear.
Q: What type of organism is Panthera leo?

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Answer

Lion

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One Big Family

How can you determine if one organism is closely related to another? It may seem easy, but it isn’t, and looks are often deceiving. For example, roses and orchids are both flowering plants, but roses grow on bushes or vines and have thorns. Many orchids don’t even grow in soil—they can grow in trees! Rose and orchid blossoms look very different, and roses and orchids cannot produce hybrids, or offspring of crosses between parents with different traits.

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Do you think roses and orchids are closely related? Explain your answer.
Now, apply the same logic to dogs. Different breeds of dogs—such as a Labrador retriever and a collie—can breed and produce offspring. So what is the difference between the rose-orchid combination and the Lab-collie combination?
What defines a species? Is appearance important? What other factors might be considered?

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Assignment

Read Ch. 18-1
Complete questions:

#4-6

Video

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Modern Evolutionary Classification

Physical similarities are only a piece of the whole classification puzzle

How closely related are bats, bees and birds?

With the advent of Darwinian Evolution, biologists now group organisms into categories that represent lines of evolutionary descent (phylogeny)
Species within a genus share a recent common ancestor, whereas species of different genus but still in the same family share a more distant ancestor
Organisms that superficially appear similar may not share a recent ancestor (i.e. convergent evolution)

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Classifications using Cladograms

As unique characteristics evolve, new species are formed; we call these characteristics derived characters
Derived characters are used to construct a cladogram, a diagram which illustrates the relationships between organisms as it relates to recently derived characters and more ancient ones.

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CLASSIFICATION BASED ON VISIBLE SIMILARITIES

CLADOGRAM

Crab

Barnacle

Limpet

Crab

Barnacle

Limpet

Molted exoskeleton

Segmentation

Tiny free-swimming larva

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Quick Lab: �How is a Cladogram Constructed? (p.453)

On a separate piece of paper, please complete this activity and turn it in next day.

Cladogram (3 marks)
Questions (6 marks)

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Six Kingdom Classification System

Eubacteria – single celled prokaryotic organisms with a cell wall composed of peptidoglycan
Archaebacteria – single celled prokaryotic organisms with a unique cell wall; extremophiles (love extreme environments)
Protista – single celled organisms with varied characteristics (if it doesn’t fit anywhere else…)
Fungi – heterotrophic organisms with cell walls made of chitin; generally decomposers
Plantae – Photosynthetic multi-cellular organisms with cell walls made of cellulose
Animalia – Heterotrophic organisms without a cell wall, capable of locomotion

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3 Domain System

Scientists have recently proposed a more general taxon than ‘Kingdom’ called a Domain
The 3 Domain System consist of:
Bacteria – corresponds to kingdom Eubacteria
Archaea – corresponds to kingdom Archaebacteria
Eukarya – Correpsonds to kingdoms protista, fungi, animalia and plantae

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The Tree of Life (aka a cladogram)

Kingdoms

Eubacteria

Archaebacteria

Protista

Plantae

Fungi

Animalia

DOMAIN EUKARYA

DOMAIN ARCHAEA

DOMAIN BACTERIA

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are characterized by

such as

and differing

which place them in

which coincides with