day 12 february 28th chapter 7 and 8

8/2/2019 Day 12 February 28th Chapter 7 and 8

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Day 12 February 28th Chapters 7

and 8

Second exam, oh no!

Chance for retakes


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Retake of Second Exam

Check your score on Springboard

If you want to retake

You have to have a study session with a tutor oryour lab TA. You must get your study guide signed

by them, turn it in to me, and then you will get a

password to retake the exam.

Must be done by spring break

Youll get an average of the two grades.


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How likely is it that you will retake

your exam?1. Very likely

2. Somewhat likely

3. Not likely4. No way, Jose!


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7.11 Multi-gene TraitsHow are continuously varying traitssuch as height influenced by genes?

Old wives tales suggest a couple of ways for predicting height:

if the baby is a boy, they say to add five inches to the mothers

height and average that with the fathers height. Or if it is a

girl, subtract five inches from the fathers height and average

that with the mothers height. Alternatively, the lore says to

just take the childs height at two years and double it.


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Polygenic Trait

A trait that is influenced by many differentgenes

Mi

nd-blowi

nglycomplicated!!!


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Additive Effects

what happens when the effects of allelesfrom multiple genes all contribute to the

ultimate phenotype

The Tall Gene

hormones and

bone length

and growthfactors oh

my!


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Why might computer nerds

be more likely to haveautistic children?

Autism involves 10 or 20 different genes!

Unusual abilities of perception, analytical

skills, and focus. This ideacalled the geek

theory of autism


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7.12 Pleiotropy: How can one

gene influence multiple traits?


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What isthebenefit of

almosthavingsickle cell

disease?


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The SRY Gene

Sex-determining Region on the Y-chromosome

Causes fetal gonads to develop as testesshortly after fertilization.

Following the gonads secretion oftestosterone, other developmental changesalso occur.


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7.13 Why are more men

than women color-blind?

Sex-linked traits differ in theirpatterns of expression in males

and females.


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Colorblindness

1. I am a non-colorblind male

2. I am a colorblind male

3. I am a non-colorblind female4. I am a colorblind female.


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If a man is color-blind, did heinherit this condition from his

mother, his father, or bothparents?


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men only get

one chance to

inher

it thenormal version

of the gene


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If a male is colorblind, from

whom did he inherit thecondition?

1. Mother2. Father

3. Grandfather

4. Aunt


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If a male is colorblind, from

whom did he inherit thecondition?

1. Mother2. Father

3. Grandfather

4. Aunt


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In which example below will there

be a chance of a daughter beingcolorblind?

1. A male who is colorblind marries a female

who is a carrier for colorblindness.

2. A male who has normal vision marries afemale who is a carrier for colorblindness.

3. A male who has normal vision marries afemale who is colorblind.

4. Choices 2 and 3 are correct.


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In which example below will there

be a chance of a daughter beingcolorblind?

1. A male who is colorblind marries a female

who is a carrier for colorblindness.

2. A male who has normal vision marries afemale who is a carrier for colorblindness.

3. A male who has normal vision marries afemale who is colorblind.

4. Choices 2 and 3 are correct.


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Chapter 8: Evolution and Natural Selection

Darwins dangerous idea: evolution by natural selection

Lectures by Mark Manteuffel, St. Louis Community College ; Clicker Questions by Kristen Curran, University ofWisconsin-Whitewater


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I feel like I know what the word

evolution means.

1. Very sure.

2. Slightly sure

3. Clueless4. I know that I dont know what the scientific

meaning of the word is.


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Evolution in Action

8.1 We can see evolution occurright before us. Therefore,evolution is a scientific process.


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Could you breed fruitflies who could livelonger than 20 hours

on average?


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Populations

are studi

ed


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When these eggs hatch, do you think theflies in this new generation will live longerthan 20 hours without food?


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Make a prediction:A population of fruit flies was starved until80% of the flies were dead. The remaining flies were fed andoffspring were produced. What do you expect to see in the nextgeneration if you repeat the starvation experiment?

1. More flies will be alive after 20 hours.

2. Fewer flies will be alive after 20 hours.

3. Fruit flies fed after 80% of the population is deadwill lay more eggs.

4. No change in the average number of fruit fliesthat were alive after 20 hours.


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Make a prediction:A population of fruit flies was starved until80% of the flies were dead. The remaining flies were fed andoffspring were produced. What do you expect to see in the nextgeneration if you repeat the starvation experiment?

1. More flies will be alive after 20 hours.

2. Fewer flies will be alive after 20 hours.

3. Fruit flies fed after 80% of the population is deadwill lay more eggs.

4. No change in the average number of fruit fliesthat were alive after 20 hours.


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After 60 generations the average starvation resistanceof fruit flies was 160 hours! What has happened to

this population of fruit flies?

1. They are genetically identical to theoriginal population.

2. The are genetically different from theoriginal population.


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After 60 generations the average starvation resistanceof fruit flies was 160 hours! What has happened to

this population of fruit flies?

1. They are genetically identical to theoriginal population.

2. The are genetically different from theoriginal population.


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What happened?

Evolution

a genetic change in the population

Natural selection the consequence of certain individual organisms in

a population being born with characteristics thatenable them to survive better and reproduce more

than the offspring of other individuals in thepopulation


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Does evolution occur?

The answer is an unambiguous: YES.

We can watch it happen in the labwhenever we want.

Recall from our discussion of the scientific method

that for an experiments results to be valid, they

must be reproducible.


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Experiments in Evolution

Dogs?

Rabbits?


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In Nature -


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Why are camels a successful species?


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Evolution

How does evolution occur?

What types of changes can evolutioncause in a population?

Five primary lines of evidence

Evolution by natural selection


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Darwins Journey to an Idea

8.2 Before Darwin, most peoplebelieved that all species had beencreated separately and wereunchanging.


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Button started the debate by suggesting the Earth

had to be at least 75,000 years old!


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Jean-Baptiste Lamarck

Biologist, early 1800s

Living species might change over time.

(Was wrong about the mechanism - he thought that change came about

through the use or disuse of features)


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Charles Lyell

Geologist

1830 book Principles of Geology Geological forces had shaped the earth and were

continuing to do so.

Gradual but constant change

This idea that the physical features of the earth were constantly changing would most

closely parallel Darwins idea that the living species of the earth, too, were gradually

but constantlychanging.


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We know the Earth is constantly

changing

Fossils of shells have been found high in theAndes Mountains

Forest fires wipe out entire species of plants andanimals.

Rivers flow, and carve out rock, creating twodistinct shores, where different species live.

Lakes dry up, killing all marine life inside.

Pollution and Toxic spills kill organisms. Volcanoes.

Humans are changing the earth.


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In the 1790s, Georges Cuvier began to explore the bottoms

of coal and slate mines and found fossils


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Why were fossils such a problem for

people at that time?

This was highly troubling for people at the

time.

http://www.bspcn.com/2009/04/03/11-extinct-animals-that-have-been-photographed-alive/


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Extinction

five mass extinctions on earth, and four in thelast 3.5 billion years - many species havedisappeared in a relatively short period of

geological time. The "Great Dying" about 250 million years ago,

which is estimated to have killed 90% of speciesexisting at the time.

Most extinctions have occurred naturally, withouthuman intervention: it is estimated that 99.9% ofall species that have ever existed are now extinct.

day 12 february 28th chapter 7 and 8

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