Part 16: Evolution of Populations

0
0
1681 days ago, 690 views
PowerPoint PPT Presentation
Section 16: Advancement of Populaces. At the point when Darwin built up his hypothesis of development, he didn't see: how heredity worked. This left him not able to clarify two things: a. wellspring of variety b. how inheritable characteristics pass from one era to the following.

Presentation Transcript

Slide 1

Section 16: Evolution of Populations

Slide 2

When Darwin built up his hypothesis of advancement, he didn't see: how heredity worked. This left him not able to clarify two things: a. wellspring of variety b. how inheritable characteristics pass from one era to the following

Slide 3

In the 1940's, Mendel's work on hereditary qualities was "rediscovered" and researchers started to consolidate the thoughts of many branches of science to build up a cutting edge hypothesis of advancement. When contemplating advancement today, researcher frequently concentrate on a specific populace . This advancement of populaces is called microevolution .

Slide 4

2. Vocabulary: population: gathering of people of similar species living in a similar territory that breed with each other.

Slide 5

2. quality pool: consolidated hereditary data. for all individuals from a populace

Slide 6

2. allele: one type of a quality

Slide 7

2. relative recurrence of an allele: # times an allele happens in the quality pool contrasted with different alleles (percent) Example Relative Frequency: 70% Allele B 30% Allele b

Slide 8

3. Wellsprings of Variation : a. transformations : any adjustment in DNA succession Can happen in light of: errors in replication natural chemicals May or may not influence a life form's phenotype

Slide 9

3. Wellsprings of Variation b. Quality Shuffling : recombination of qualities that happens amid generation of gametes Cause most inheritable contrasts between relatives Occurs amid meiosis therefore, sexual proliferation is a noteworthy wellspring of variety in living beings. In spite of quality rearranging, the recurrence of alleles does not change in a populace. Clarify why this is genuine . Like a deck of cards – regardless of how often you rearrange, same cards (alleles) are dependably there.

Slide 11

4. Quality Traits: A) Single quality characteristic: controlled by single quality with two alleles Examples : dowager's pinnacle, drifter's thumb, tongue moving

Slide 12

(4. Quality Traits:) B) Polygenic attribute: controlled by at least 2 qualities, each with at least 2 alleles Examples: tallness, hair shading, skin shading, eye shading Most human characteristics are polygenic.

Slide 13

Do the accompanying diagrams demonstrate the circulation of phenotypes for single-quality or polygenic attributes? Clarify. sort: single quality why? Just two phenotypes conceivable Example: tongue roller or non-tongue roller sort: polygenic why? Various (numerous) phenotypes conceivable Example: stature extend 4feet to 9 feet all

Slide 14

5. Normal determination follows up on phenotypes , not genotypes . Case: in a woodland canvassed in chestnut leaves, soil and shakes which mouse will survive better cocoa or white? Cocoa, more covered up.

Slide 15

BB Bb 5. On the off chance that cocoa is prevailing can the a predator differentiate between: Mouse with most elevated wellness will have the most alleles passed on to the people to come. White mouse will have low wellness ?

Slide 16

BB Bb 5. Which mouse will have the most minimal wellness? White, bb (passive) Will the wellness of BB and Bb vary? Why? No, Both BB and Bb have a similar wellness favorable position of being chestnut ?

Slide 17

6. Three courses in which regular determination influences polygenic characteristics.

Slide 18

Key Low mortality, high wellness High mortality, low wellness Food turns out to be rare. a. Directional Selection : people toward one side of the bend have higher wellness so advancement causes increment in people with that quality Individuals with most astounding wellness : those toward one side of the bend Example: Galapagos finches – nose measure

Slide 19

Key Low mortality, high wellness High mortality, low wellness Food turns out to be rare. Directional Selection (page 398) Directional Selection

Slide 20

Stabilizing Selection Key Low mortality, high wellness High mortality, low wellness Selection against both extremes keep bend limit and in same place. Rate of Population Birth Weight b. Balancing out Selection: people at the focal point of the bend have most astounding wellness; advancement keeps focus similarly situated yet limits the bend Individuals with most noteworthy wellness: close to the focal point of the bend (normal phenotype) Example: human birth weight

Slide 21

Stabilizing Selection Key Low mortality, high wellness High mortality, low wellness Selection against both extremes keep bend limit and in same place. Rate of Population Birth Weight Stabilizing Selection

Slide 22

Disruptive Selection Largest and littlest seeds turn out to be more typical. Enter Population parts into two subgroups represent considerable authority in various seeds. Low mortality, high wellness Number of Birds in Population Number of Birds in Population High mortality, low wellness Beak Size Beak Size c. Troublesome Selection : people at both closures of the bend survive superior to the center of the bend. People with most noteworthy wellness: both finishes of bend Example: fowls where seeds are either extensive or little

Slide 23

Disruptive Selection Largest and littlest seeds turn out to be more typical. Enter Population parts into two subgroups having some expertise in various seeds. Low mortality, high wellness Number of Birds in Population Number of Birds in Population High mortality, low wellness Beak Size Beak Size Disruptive Selection (pg 399)

Slide 25

Quiz Monday!! Development audit ½ sheet. (yes a few inquiries are missing) Thursday and Friday's ideas will be on the test: Directional, Stabilizing and Disruptive determination. Geographic, Behavioral, Temporal Isolation Small populaces brought on by bottleneck and originator impact

Slide 26

The Process of Speciation The development of new organic species, more often than not by the division of a solitary animal types into at least two hereditarily unmistakable one.

Slide 27

Three Isolating Mechanisms : Isolate species framing subspecies and maybe bringing about speciation. Geographic Isolation Behavioral Isolation Temporal Isolation

Slide 28

1. Geographic Isolation Two populaces isolated by a geographic hindrance ; stream, lake, gorge, mountain extend.

Slide 29

Example: 10,000 years back the Colorado River isolated two squirrel populaces. Kaibab Squirrel Abert Squirrel

Slide 30

This brought about a subspecies, yet did not bring about speciation on the grounds that the two can at present mate if united Kaibab Squirrel Abert Squirrel

Slide 31

2. Behavioral Isolation Two populaces are equipped for interbreeding however don't interbreed on the grounds that they have distinctive 'romance ceremonies' or other way of life propensities that vary.

Slide 32

Example: Eastern and Western Meadowlark Eastern and Western Meadowlark populaces cover amidst the US

Slide 33

Example: Eastern and Western Meadowlark Male winged creatures sing a tangling tune that females like, East and West have distinctive melodies. Females just react to their subspecies tune.

Slide 34

3. Fleeting Isolation Populations repeat at various circumstances January 1 2 3 4 5 6 7 8 9 10 11 12 13

Slide 35

Example: Northern Leopard Frog & North American Bullfrog Mates in: Mates in: April July

Slide 36

Conclusion : Geographic, Behavioral and Temporal Isolation are altogether accepted to prompt to speciation.

Slide 37

However: No cases at any point saw in creatures two or three cases that may exhibit speciation exist in plants and a few creepy crawlies .

Slide 39

Genetic Drift irregular change in allele recurrence that happens in little populaces

Slide 40

The consequences of hereditary crosses can for the most part be anticipated utilizing the laws of likelihood . In little populaces, be that as it may, these forecasts are not generally precise. a. Originator impact: allele frequencies change because of movement of a little subgroup of a populace Example: organic product flies on Hawaiian islands

Slide 41

Two wonders that outcome in little populaces and cause hereditary float Founder Effect Bottleneck Effect

Slide 42

Founder impact allele frequencies change because of relocation of a little subgroup of a populace

Slide 43

Sample of Original Population Descendants Founding Population A Founding Population B Founder Effect: : Fruit Flies on Hawaiian islands

Slide 44

2. Bottleneck impact real change in allele frequencies when populace diminishes significantly because of fiasco Example: northern elephant seals diminished to 20 people in 1800's, presently 30,000 no hereditary variety in 24 qualities

Slide 45

Bottleneck Effect: Northern Elephant Seal Population Hunted to close extintion Population diminished to 20 people in 1800's, those 20 repopulated so today's populace is ~30,000 No hereditary variety in 24 qualities

Slide 46

Bottleneck Effect Original populace

Slide 47

Bottleneck Effect Catastrophe Original populace

Slide 48

Bottleneck Effect Catastrophe Surviving populace Original populace

Slide 49

Another photo to outline bottleneck impact

SPONSORS