BIOLOGY BStandard 2B: Evolutionary ProcessesWeek 1Ms. Darlak

Warm-up 04/14 Who said what?

1. He said giraffes stretched their necks to reach food. Their offspring and later generations inherited the resulting long necks.

2. He said that organisms, even of the same species, are all different and that those which happen to have variations that help them to survive in their environments survive and have more offspring.

3. He believed that the desires of animals have nothing to do with how they evolve, and that changes in an organism during its life do not affect the evolution of the species.

LamarckLamarck

DarwinDarwin

DarwinDarwin

AGENDA 04/14 Homework Check –

Natural Selection pp. 6-8Adaptations pp. 11-13

Variation Activity Modes of Selection p.8

HOMEWORK: Complete the practice pps. 9-10.

CLASS/HOMEWORK CHECK Page. 6 Fill in the table

using statements from story.

Page 7-8. same, same.

Pages 11-13 Types of Adaptations 3B Adaptation Assignment

NATURAL SELECTION Natural selection is the gradual,

nonrandom process by which biological traits become either more or less common in a population as a function of differential reproduction of their bearers.

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Process by which evolutionary changes occur in living organisms over millions of years.

Analogous to artificial selection.

______________________ Individuals that are better able to cope with the challenges of their environment tend to leave more offspring than those less suited.

Example:

______________________ All species have

genetic variation.

Example:

______________________ Living things face many challenges in the struggle to exist. Individuals of species often compete with one another to survive.

Example:

______________________ The characteristics of the individuals best suited to a particular environment tend to increase in a population over time.

Example:

Much of the wildlife was killed for food, and poachers killed elephants for their ivory tusks.

Tusk and tuskless elephants.

1998 population increased to 1,200, 30% were tuskless.Elephants are bad example of this, produce less care and protect more.

A survey in 1998 revealed that as many as 30 percent of the adult elephants did not have tusks. Ugandan wildlife officials also noted a decline in poaching. It was 1% in 1930.

OVERPRODUCTION

VARIATION

SELECTION

ADAPTATION

All students lined up in the back of the room by height.

Shortest people next to the windows, tallest people nearer to the door.

Counted the number of students in each height range 4 – 4.5 “ 4.6- 4.11” 5.0 -5.8” 5.9- 5.11” 6.0- 6.5”

VARIATION WITHIN A SPECIESEXAMPLE : HEIGHT IS POLYGENIC

4’5”4’5” 5’5”5’5” 6’5”6’5”

# of

Stu

dent

sHEIGHT DISTRIBUTION ( BIOLOGY STUDENTS)

2

4

6

8

1

0

12

14

Normal Distribution

CLASS DATA: EYE SPREAD VARIATION

Measurement Range (mm) Number of Students

> - 90 mm91-97 mm 98-104 mm

105-111 mm112-118 mm119-125 mm126-132 mm133 - < mm

CLASS DATA: ARM LENGTH VARIATION

Measurement Range (mm) Number of Students

> - 600 mm601-650 mm651-700 mm701-750 mm751-800 mm801-850 mm851- 900 mm

901- < mm

CLASS DATA: WRIST CIRCUMFERENCE

Measurement Range (mm) Number of Students

> - 120 mm121 - 136 mm137 – 152 mm153 – 168 mm169 - 184 mm185 - 200 mm201 - 216 mm

217- < mm

LT1 CHECK WARM-UP 04/15 What are the four steps of natural selection? Explain and give an example for each step.1. OVERPRODUCTION: Organisms produce more

organisms than can survive.2.2. VARIATION:VARIATION: In any population, variations exist.3. SELECTION & SURVIVAL : Individuals with certain

“useful” or beneficial variations survive and pass on their variations to the next generation.

4. REPRODUCTION & ADAPTATION: Overtime, offspring with “beneficial” variations will make up most of the population.

AGENDA 04/15 NZ Bird Adaptation Sort p.13 Finish Variation Graphs & AnalysisModes of Selection Notes p.8Modes of Selection Practice p.9-10

HOMEWORK: Complete the practice pps. 9-10.

VARIATION ACTIVITY In groups of 2 or 3

Make 3 measurements use paper then meter stick

Add to class dataGraph distributionAnswer analysis Questions

NZ BIRD ADAPTATION SORT P.13

Due to geographical isolation, New Zealand’s bird life evolved in the absence of ground-dwelling predators.

Some birds evolved larger body size and loss of flight, as an adaptation to fly was not required to escape these ground-dwelling mammalian predators.

As a table sort the different bird adaptations into the correct column.

Structural Behavioural PhysiologicalBirds have different shaped beaks and feet suited to the habitat they live in.

If there is thick snow cover on the ground during winter, takahē will nest in forested areas to provide shelter.

Kererū are one of the few birds to produce ‘crop milk’ – a protein-rich milky secretion from the walls of their crops to sustain their chicks.

Kiwi and takahē have vestigial wing buds, which are incapable of flight.

Kererū fledglings spend 1–2 weeks with their parents before becoming independent.

Kiwi hatch with an internal yolk sac. This sustains the chick in its first week of life.

Kiwi are nocturnal birds.

Kiwi have fine whiskers at the base of their beak to aid their navigation in the dark.

Male kākāpō let out a ‘booming’ noise from dug-out bowls in the earth to attract a female.

Kiwi have nostrils at the ends of their beaks

Many birds such as the kererū and tūī perform display dives to attract a mate.

Structural Behavioural PhysiologicalKiwi plumage blends in with the undergrowth to allow them protection from predators through camouflage.

The breeding cycle of kākāpō is tightly linked with the fruiting of the rimu tree. In abundant fruiting years, more chicks are often born.

The bill of the takahē extends onto its forehead as a shield.

The kākāpō has a ‘freezing’ response to danger.

The kererū has the widest gape of any New Zealand forest bird. This enables it to swallow the large berries of native trees.The tūī has a long curved beak and a fine brush-tipped tongue that enables it to extract nectar from forest tree flowers.Tūī have hollow bones and no teeth, which makes their body light for flight.

MODES OF SELECTION P.8

Modes of Selection

= Variation

Limited = Phenotype

s

Directional selection: this type of selection works to select the extreme of one trait.

Selective pressure toward one extreme

Finches Clip

Examples:Peppered Moth ColorsFlowers: the brightest

color might be selected for in order to attract the most pollinators.

Greyhound dogs: Dogs with the greatest speed are selected to breed.

Most Artificial Selection is Directional

Stabilizing selection: this type of selection works against the two extremes of a trait to make the population more uniform.

Pressure towards the average

Clip

Examples:Bird Songs- females only recognize males

that have the same song as their father.Birth weight of human babies to keep

them at an intermediate weight, because babies that are too big or too small have less chance of being born health.

Disruptive selection: this type of selection selects against the mean of the population.

Diversifies the species towards the two extremes.

Duck Clip

Examples:Moth Color- Light or

Dark only selected.Two types of seeds to

eat for a population of birds, either of two different beak shapes (sharp or blunt) might be selected for, but the intermediate beak not good at eating either seed.

HOMEWORK: Complete the practice pp. 9-10.

WARM-UP 04/16Match the Type of Selection with the correct

example.

1. Directional Selection2. Stabilizing Selection3. Disruptive Selection

A. Female birds prefer males that sing exactly like their father’s song. B. Smaller mice survive because they can squeeze through the holes in the walls.C. Plants with average sized flowers are picked for bouquets.

What is happening in each graph?

Who is being selected for? Who is being selected against? Directional, Disruption or Stabilizing?

1.1.

2.2.

3.3.

AGENDA 04/16 Adaptation Check Homework Check pp.9-10 Selection and Survival

Stabilizing Directional Disruptional

1. BIRTH WEIGHT P.9

2. ANTELOPE P.8

3. YING YANG BUTTERFLY

4. GREEN-EYED TREE FROGS P.9

5. RED BUD FLOWER

6. FRILLED LIZARD

EVOLUTION OF POPULATIONS

Occurs when there is a change in relative frequency of alleles

What are allele frequencies?

ALLELE FREQUENCYALLELE FREQUENCY

1717

Frequency of each alleleFrequency of each allele

Total Alleles = 30Total Alleles = 30 Count # of B = Count # of B = Count # of b =Count # of b =

It is a Percent, so…Allele frequency of B

17/30 x 100 =Allele Frequency of b

13/30 x 100 =

1313

. 56 or 56.67%. 56 or 56.67%

.43 or 43.33 %.43 or 43.33 %

Allele Frequency

E = 31% + 32/2 = 47%

e = 37% + 32/2 = 53% CLIP

GALAPAGOS TORTOISESBrownBrown= N Short-necked GreenGreen= n Long-necked

Starting PopulationPhenotypic Frequency 50% Short-necks (NN) 50% Long-necks (nn)

Allele Frequency for 8 individuals

N = 8/16 = .50 or 50% n = 8/16 = .50 or 50%

SELECTION AND SURVIVAL PP. 21 -22BrownBrown= NN Short-necked GreenGreen= nn Long-necked1. Round 1: Creating the Parents

Four small pieces of brown (NN) Four small pieces of green (nn)

2. Round 2: Breeding the Parents 16 children from four pairs

3. Round 3: Breeding the Children Food shortage remove 8 brown

4. Round 4: Breeding the Grandchildren Food still scarce, remove 8 more brown Sh

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RECORD YOUR GROUP DATA HERE P3Group Children Grand Children Great-Grand

ChildrenShort Neck Allele (N)

Long NeckAllele (n)

Short Neck Allele (N)

Long NeckAllele (n)

Short Neck Allele (N)

Long NeckAllele (n)

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10

COMPUTER LAB C

10 Examples of Natural Selection pp. 15 See link on website