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Mutation A change in a DNA sequence, usually occurring because of errors in replication or repair. Mutation is the ultimate source of genetic variation.

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Presentation on theme: "Mutation A change in a DNA sequence, usually occurring because of errors in replication or repair. Mutation is the ultimate source of genetic variation."— Presentation transcript:

1 Mutation A change in a DNA sequence, usually occurring because of errors in replication or repair. Mutation is the ultimate source of genetic variation.

2 Migration or Gene FLow The chance of an individual migrating to another population and sharing it’s genes there.

3 Genetic Drift The drift over time of allele frequencies in a population due to random sampling effects forming successive generations.

4 Natural Selection A process of evolution in which traits that result in better fitness of an individual survives to the next generation.

5 ___________________ – credited with the theory of evolution Charles Darwin

6 Evidence that supports the theory of Evolution Fossil Records Geographic Distribution Ebryology Homologous Structures Vestigial Structures Biochemistry Artificial Selection

7 VII. Natural Selection- process by which organisms with beneficial traits will more likely survive long enough to reproduce and pass on those beneficial traits. Natural Selection- Works much like artificial selection, but the environment “selects” the best traits. –A. Causes Survival of the fittest! –B. Fitness is a result of adaptation. Fitness= the ability of an individual to survive Adaptation= an inherited characteristic that increases the chance of survival

8 VIII. How does survival of the fittest work?” –The organism that is most capable of surviving and passing its genes on in an environment will do so. –This will cause those genes to be more dominant in a population.

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10 IX. Darwins 5 Points 1. Variation– populations have differences –DNA mutations are the ultimate source of variation in organisms –These mutations are part if the organism’s genetics, and are passed on to its offspring

11 1. Variation- dark and light mice

12 What else can cause variation other than mutations? Migration- introduces new traits and variation with in a population

13 IX. Darwins 5 Points 2. Some variations are favorable –Favorable variations are those that give an organism an advantage to reproduce in a certain environment

14 2. Favorable Trait- dark color

15 IX. Darwins 5 Points 3. Overproduction – More offspring are produced than survive

16 3. Overproduction

17 IX. Darwins 5 Points 3. Overproduction – More offspring are produced than survive

18 IX. Darwins 5 Points 4. Adaptation – those that survive are the ones with the favorable traits

19 4.Camoflague is an adaptation

20 IX. Darwins 5 Points 5. Selection – the population will change over time as a result of passing inheritable traits from adaptations

21 5. Natural selection selects for the darker mouse and against the white mouse …And the population will will include darker mice over time.

22 There are two variations in rabbits: some strictly eat grass and some strictly eat berries and flowers. A drought occurs one year, and the plants have difficulty producing any extras (flowers, berries, etc.).They can only try and keep themselves green. The rabbits have had babies all year long but many are eaten by foxes or hawks. Due to the drought, many have starved to death. What rabbit will natural selection select AGAINST? ______________ FOR?______________ Population has variations. Some variations are favorable. More offspring are produced than survive.__________________________________________ Those that survive have favorable traits. A population will change over time.

23 1)There are 2 variations in worms: worms that eat at night (nocturnal) and worms that eat during the day (diurnal). The birds eat during the day and seem to be eating ONLY the diurnal worms. The nocturnal worms are in their burrows during this time. Each spring when the worms reproduce, they have about 500 babies but only 100 of these 500 ever become old enough to reproduce. a. What worm has natural selection selected AGAINST? ______________ FOR? _____________ Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. _________________________________________________________________ Some variations are favorable. _____________________________________________________________ More offspring are produced than survive._________________________________________________ Those that survive have favorable traits. ____________________________________________________ A population will change over time. ________________________________________________________

24 2) There are 3 variations in polar bears: thick coats, thin coats and medium coats. It is fall, soon to be winter. The temperatures are dropping rapidly and the bears must be kept warm, or they will freeze to death. Many of the bears have had ~2 cubs each but due to the extreme temperatures, many mothers only have one cub left. a. What bear will natural selection select AGAINST? ______________ FOR? ______________ Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. _________________________________________________________________ Some variations are favorable. _____________________________________________________________ More offspring are produced than survive._________________________________________________ Those that survive have favorable traits. ____________________________________________________ A population will change over time. ________________________________________________________

25 3) In ostriches, there are 2 variations: ones that run fast and those that run slowly. The fast birds can reach up to 40 miles an hour. Jackals love to eat ostrich, and they can reach speeds of up to miles per hour. A flock of ostrich will lay ~ 10 eggs (each mother only lays 1), but many rodents break into the eggs and eat the fetus before they hatch. a. What ostrich will natural selection select AGAINST? __________ FOR? _____________ Darwin's 5 points: Identify the 5 points in the scenario above. Population has variations. _________________________________________________________________ Some variations are favorable. _____________________________________________________________ More offspring are produced than survive._________________________________________________ Those that survive have favorable traits. ____________________________________________________ A population will change over time. ________________________________________________________

26 1. Natural selection – environment “selects” traits

27 1.Artificial selection – humans “select” traits

28 Evolution & Predator/Prey Relationships

29 I. Evolution & Predator/Prey Relationships A. Adaptation-An inherited trait that gives an organism a favorable advantage to reproduce in a certain environment.

30 Example

31 1. What would be an example of an adaptation that allows predators to capture prey? 2. What would be an example of an adaptation that allows prey to avoid being captured?

32 Acute Senses

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34 Snails and Crabs

35 II. Camouflage, Mimicry and Warning Coloration

36 Camouflage, Mimicry and Warning Coloration Did you see… a Cheetah? an Owl? an Octopus?

37 A. Mimicry - the ability of some creatures to imitate others, either by sound or appearance for protective purposes

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40 B. Camouflage - Protective coloring or another feature that conceals an animal and enables it to blend into its surroundings.

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46 Camouflage Stick Bug

47 Chameleon

48 C. Warning Coloration Conspicuously recognizable markings of an animal that serve to warn potential predators of the nuisance or harm that would come from attacking or eating it. The bold patterns of skunks and the bright colors of poison arrow frogs are examples of warning coloration.

49 III. Natural Selection, Predators, and Prey A. Prey that can survive attacks from prey will reproduce and pass those traits down to their offspring. B. Predator that can beat the competition for food will survive and pass on their dominant traits to their offspring

50 C. Carrying Capacity – the number of individuals that an environment can support –Affected by predator prey relationships and the environment

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53 Bear and Salmon

54 A = lag phase (very few organisms to begin with – reproduction is slow B = acceleration phase C = exponential phase F = population crash due to limited resources

55 You can see an obvious cycle, prey numbers go up followed by predator numbers going up, then prey drops, predators drop

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57 Name: ___________ As you watch the video – place each animal shown from the rainforest in the correct category below. Camouflage: Mimicry: Warning Coloration: ________________ 2. 2._____________ 2.________________ 3. 3._____________ 4.________________ 5.________________ 6.________________ 7.________________ 8.________________ 9.________________ 10.________________ Write a one to two sentence summary of this video, explaining the significance of these three terms – hint: use “adaptation” in your explanation. Video/United Streaming - World of Nature: Insect Disguises


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