Evolutionary Theories

1. Describe 1 of Lamarck’s hypotheses 2. Are all of Lamarck’s hypotheses currently

supported? 3. List 2 observations Darwin made on his

voyage on the Beagle 4. In what way did Lyell influence Darwin? 5. In what way did Malthus influence Darwin?

Darwin’s journey (continue this after the reading quiz) Charles Darwin (1809-

1882) sailed on the HMS Beagle in 1831

Observed huge diversity

2 questions: Where did all of these

new species come from? Why have so many

disappeared?

1. All species produce far more offspring than required just to replace parents. This would result in exponential growth if populations were not limited. ("Essays on Population" by Thomas Malthus)

2. Populations do not, however, increase exponentially. They generally remain stable in size.(Field observations)

3. The resources in the environment are limited. (Field observations)

1. Because of the limited resources in the environment, there is competition among individuals. Only a small fraction of the individuals born can survive.

Darwin’s evidence and Darwin’s evidence and inferencesinferences

Darwin’s evidence and inferences 4. There is variation within species and populations. Some individuals possess characteristics that are better suited to the environment than others. (Field observations)

5. Most physical, and some behavioral characteristics are inherited.(Breeding experiments with pigeons. "Artificial selection")

2. Those individuals with the best characteristics for the particular environment will do a better job of producing and providing for offspring than will others with less "fit" characteristics.

Darwin’s evidence and inferences 6. Geologic

processes are very, very slow. (Principles of Geology by Charles Lyell, work by Hutton, as well as Darwin's own studies of geology)

3. The earth must be very, very old. Over very great periods of time, "good" characteristics have time to accumulate and less fit ones have diminished.

Reading quiz: 8-23/24 (have timeline and assignment sheet at your desk ready to be stamped) 1. Define adaptation 2. Define natural selection 3. Is natural selection the same thing as

evolution? Explain. 4. List 2 of Darwin’s points about his theory of

evolution

Reading quiz: 8-23/24

1. Define adaptation Inherited trait that provides a selective advantage (increases

fitness) 2. Define natural selection

Differential rate of reproduction (or survival of the fittest organisms)

3. Is natural selection the same thing as evolution? Explain. NO! Evolution refers to changes of a population over time.

Natural selection is the mechanism that can drive evolution 4. List 2 of Darwin’s points about his theory of evolution

Variation within a species exists, some species are better suited to survive, favorable traits (adaptations) tend to spread in a population, living species evolved from organisms (descent)

Natural Selection There is variation in all species Some variation better adapted for the environment than

others Natural selection (survival of the fitter): Individuals with

characteristics better adapted for the environment will survive and have more viable offspring than non adapted individuals.

Lamarck’s evidence and inference Comparisons between

current species and fossils: lines of descendents

Use and disuse Inheritance of acquired

characteristics

What exactly is a theory? Explain which picture describes Lamarck’s

view and which pictures describes Darwin’s view.

Reading quiz: 8-25 (pass SG 4 and assignment sheet to the center. Natural selection lab will be collected at the end of class) 1. Define a vestigial structure 2. Define a homologous structure 3. Give an example of a homologous

structure (description, not picture) 4. Describe how proteins can be used to

show relationships among species 5. What is 1 limitation of using proteins to

compare species

Evidence for evolution

Evidence for evolution

Homologous structure: Provides evidence for common ancestor (note: Humans did NOT evolve from apes, but rather a common ancestor

Vestigial structures Embryo similarities Biochemical similarities

Reading quiz: 8-28/29

1. According to the most current scientific evidence, how old is the earth?

2. We have found fossils of fish and amphibians. What did Darwin predict would eventually be found?

3. Define a fossil 4. List 2 ways fossils can form

Forming a deduction

Remember these terms… Hypothesis, experiment, prediction

A deduction combines all three. It is a very formalized way to guide an experiment.

IF hypothesis AND experiment THEN prediction

We are interested whether males or females are better at biology

IF _____ AND ___ THEN ___ .

Fossils

Remains or impressions of organisms preserved, either in tar, sap, sedimentary rock or other

Are the remains of all organisms preserved? Do scientists have all of these remains? What can the fossil record tell us?

How do species arise?

Must be reproductively isolated. This develops from Behavioral isolation Geographic isolation Temporal isolation

Darwin’s finches

Founders arrive

Separation of population

Variation arises

Reproductive isolation

Ecological competition

Continued evolution

New species case study

You have just discovered 2 new populations of birds living in the Amazon Rain Forest. Although they look the same, they seem to sing different songs. You first want to know whether these 2 groups are different species or not. How do you decide?

You find out that they are separate species. Propose an explanation for how this speciation occurred. Be creative and use all the vocabulary learned in class, evolution natural selection speciation, etc.

Reading quiz: 8-30/31

1. Define reproductive isolation 2. Define punctuated equilibrium 3. List 2 points of Darwin’s theory of evolution

(natural selection) 4. Define speciation

Reading quiz: 8-30/31

1. Define reproductive isolation When 2 groups of organisms cannot interbreed (reproduce

with each other) 2. Define punctuated equilibrium

Theory in which periods of rapid evolution is separated by periods of little/no change

3. List 2 points of Darwin’s theory of evolution (natural selection) Variation within a species exists, overpopulation, some species

are better suited to survive, favorable traits (adaptations) tend to spread in a population, living species evolved from organisms (descent)

4. Define speciation The process of forming new species

Another example of evolutionBacterium Mycobacterium tuberculosis infects individuals and causes the lung disease TB

Antibiotics created to kill the bacteria

New strains (variations) appeared. How?

Another example of evolutionBacterium Mycobacterium tuberculosis infects individuals and causes the lung disease TB

Antibiotics created to kill the bacteria

New strains (variations) appeared. How?

Variations exist

Non resistant bacteria die

A change randomly occurs in the bacteria

Antibiotic resistant strain thrives!

Patterns of evolution jigsaw

Topics Punctuated equilibrium (282) Adaptive radiation (Divergent evolution) (handed out) Convergent evolution (307) Coevolution (handed out)

First go through topic with group. Use textbook and study guide. Takes notes on your discussion. UNDERSTAND YOUR TOPIC!

Create a poster to visually display your topic. This should have the topic title, picture(s), and key points.

You will rotate explaining your topic to others and listening to others explain their topic. TAKE NOTES!

Practice essay question

Support the following statement by clearly defining terms, explaining relationships, and giving examples. The evolutionary theories of Lamarck and Darwin differed, yet had commonalities.

Rubric

Does the response… Describe the following points (inferences) about Darwin’s theory – variation

within species, competition, survival of the fittest organisms, inheritance of adaptations

Describe the following points (inferences) about Lamarck’s theory – use and disuse, inheritance of acquired characteristics

Clearly states differences in these descriptions Clearly states commonalities in these descriptions Gives an example of each

Does the response… Use the following format IF ___ AND ___ THEN Provides a tentative, testable explanation after IF Provides a general description of the lab after AND Provides a measurable prediction after THEN (such as more prey will survive

or # of prey living)

How do I study? Study frequently, differently, and actively You are given the opportunity to succeed and get any grade you

want. It is up to YOU to do this and earn your grade What NOT to do

Only study the night before or study not at all Simply reread information (textbook, etc.) Study in only one way

What TO DO Review notes and work EVERY day, and even more DAYS before

an exam While reviewing study guide, labs, worksheets, and textbook, keep

asking yourself “do I understand this” and keep writing down notes, making outlines, answering questions

Do different things. Flash cards, end of the chapter questions, draw out diagrams

Study with a group, attend review sessions, see ME for help!

How to study

First assess yourself (be metacognitive) For each study guide question, mark it with a +, √,

or – Focus more on your (–) and (√) questions. Use

study guide and notes a primary reference (textbook as last resort).