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History of Biological Diversity Evolution: Darwin’s travel

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1 History of Biological Diversity Evolution: Darwin’s travel

2 Developing the Theory of Evolution The Galápagos Islands
Darwin noticed that the different islands all seemed to have their own, slightly different varieties of animals. Somewhat similar species that suited their particular environment. Copyright © McGraw-Hill Education Darwin’s Theory of Evolution by Natural Selection

3 Origin of Species: Darwin’s Book
In 1859 On the Origin of Species presented evidence and proposed a mechanism for evolution that he called natural selection.

4 Today, scientists use evolution to mean cumulative change in a group of organisms through time.
Natural selection is not synonymous with evolution – it is a mechanism by which evolution occurs. Artificial selection: (instead of natural) humans select which organism get to reproduce and pass on genes Copyright © McGraw-Hill Education Darwin’s Theory of Evolution by Natural Selection

5 Peppered Moth: Natural Selection
The light colored form was the predominant form in England prior to the Industrial Revolution. Around the middle of the 19th century the darker form began to appear. It was first reported in By % of the moths in Manchester were the dark variety. In recent years, the burning of cleaner fuels and Clean Air regulations has reduced the pollution there and the lighter colored moths have increased in numbers.

6 First 6 Minutes

7 Types of Selection: a. Artificial Selection – humans select for variations in plants and animals that they find useful. b. Natural Selection – also means “Survival of the Fittest”. - Fitness in this sense does not mean strongest. - Fitness in Darwin terms means reproduction. The one who survives long enough to reproduce the most is the one with the highest fitness.

8 Types of Natural Selection
-Evolution acts on the phenotype of the individual, not the genotype. - There are 4 types of selection that can occur on a population. 1. Directional Selection – when individuals at one end of the curve have a higher fitness than individuals in the middle or at the other end of the curve.

9 2. Stabilizing Selection
– when individuals near the center of the curve have higher fitness than individuals at either end of the curve, narrowing of the graph.

10 a. genetic drift – random change in allele frequency.
3. Disruptive Selection – when individuals at either end have a higher fitness and individual near the middle of the curve are selected against. - Over time with enough selection a population can go through genetic drift. a. genetic drift – random change in allele frequency.

11 4. Sexual Selection: the ability to attract a mate

12 TAKE YOUR ORNAMENTS HOME!!!!
HOMEWORK PAP and Academic TAKE YOUR ORNAMENTS HOME!!!!

13 Support for Evolution Evidence for evolution comes from:
1. The fossil record: remains in layers of rock 2. Comparative anatomy a. Analogous structures b. Homologous Structures c. Vestigial Structures 3. Comparative embryology 4. Comparative biochemistry 5. Geographic distribution Copyright © McGraw-Hill Education Evidence of Evolution

14 1. Support of Evolution: Fossil Record
Fossil Record – Fossils are the remains of ancient organisms found in layers of rock in the Earth.

15 Support of Evolution The layers of rock tell the history of the Earth, while the fossils found within the rock tell a history of life. The fossils are thought to be the same age as the rock they are found in.

16 Support for Evolution: The fossil Record
Researchers consider two major classes of traits when studying transitional fossils: Derived traits are newly evolved features, such as feathers, that do not appear in the fossils of common ancestors. Ancestral traits are more primitive features, such as teeth and tails, that do appear in ancestral forms. Copyright © McGraw-Hill Education Evidence of Evolution

17 2. Support for Evolution: Comparative Anatomy
A. Homologous structures are anatomically similar structures inherited from a common ancestor. Similar structures with different function (similar bones) (common ancestor) Copyright © McGraw-Hill Education Evidence of Evolution

18 Structures are different but have similar function.
Support for Evolution Comparative anatomy B. Analogous structures can be used for the same purpose and be superficially similar in construction, but are not inherited from a common ancestor. Structures are different but have similar function. Copyright © McGraw-Hill Education Evidence of Evolution

19 Support for Evolution Comparative anatomy C. Vestigial structures are structures that are the reduced forms of functional structures in other organisms. Evolutionary theory predicts that features of ancestors that no longer have a function for that species will become smaller over time until they are lost. snake pelvis human appendix Evidence of Evolution Copyright © McGraw-Hill Education

20 3. Support for Evolution: Comparative embryology
Embryos of many animals with back-bones are very similar.

21 Similarities in DNA and protein sequences suggest relatedness.
4. Support for Evolution: Comparative Biochemistry Common ancestry can be seen in the complex metabolic molecules that many different organisms share. The more closely related species are to each other, the greater the biochemical similarity. Similarities in DNA and protein sequences suggest relatedness. Copyright © McGraw-Hill Education Evidence of Evolution

22 5. Support for Evolution: Geographic distribution
The distribution of plants and animals that Darwin studied were what first suggested evolution to him. The distribution of plants and animals around the world is studied in the field of biogeography. Evolution is linked to migration patterns, climate, and geological forces (such as plate tectonics). Copyright © McGraw-Hill Education Evidence of Evolution

23 Adaptation- an inherited trait that increases a population’s chance of survival and reproduction in a particular environment Fitness is a measure of the relative contribution an individual trait makes to the next generation. The better an organism is adapted to its environment, the greater its chances of survival and reproductive success. Copyright © McGraw-Hill Education Evidence of Evolution

24 PAP Activity

25 Academic Activity

26 Bird Beak Lab: ALL

27 PAP Webquest

28 Academic Webquest

29 Through adaptations, populations often
become suited to a specific job called a niche. 1. niche – the role a population plays in a habitat - job, profession, role 2. Competition arises when 2 populations occupy the same niche.

30 Adaptation Types of adaptations
Camouflage Adaptation Types of adaptations Camouflage is a suite of morphological adaptations that allow an organism to blend into its environment. Mimicry is a type of morphological adaptation where a species evolves to resemble another species. Antimicrobial resistance develops in some bacteria in response to sub- lethal exposure to antibiotics. Mimicry Copyright © McGraw-Hill Education Evidence of Evolution

31 Can you find the hidden animals? Giraffe

32 Wolf

33 Willow Ptarmigan

34 Caiman

35 Great Horned Owl

36 American Pike

37 Blue-crowned Parrot

38 Horned Adder

39 Leopard

40 Gyrfalcon

41 California Ground Squirrel

42 Spotted Deer

43 Impala

44 Cheetah

45 Common Snipe

46 Wandering Tattler

47 Nighthawk

48 Coyote

49 Blue Dacnis

50 Hide and Seek: ALL

51 Population Genetics - study of the traits in a population
A. Population – a group of interbreeding organisms (a species) living in a given area B. Gene Pool – combined genetic material of all the members of a population C. Gene Flow-the transfer of alleles or genes from one population to another. D. Genetic Drift- any change in the allelic frequency in a population that results from chance.

52 E. Allele – forms that a gene can take
F. Allele Frequency – the number of each allele for a trait This “changing of the gene pool” (allele frequency) has a name —› Evolution. Evolution – the changes in the gene pool of a population over time.

53 Speciation – formation of a new species 1. Reproductive Isolation
- 2 or more species cannot interbreed 2. Geographic /Allopatric Isolation - 2 populations are separated by geographic barriers ●examples: rivers, mountains, bodies of water Example: Three similar species of orchid all live in the same rain forest. Each species releases pollen only on a single day. Because they release the pollen on different days, they cannot pollinate one another.

54 Types of Evolution Convergent Evolution: less alike to more alike
Divergent Evolution=Adaptive Radiation: more alike to less alike Coevolution: evolve together Punctuated equilibrium: happens in short period of time

55 Convergent Evolution:
Occurs when different organisms that live in similar environments become more alike in appearance and behavior. Less alike to more alike Examples: - Bird wings/insect wings - Shark fins/dolphin fins Draw the diagram in Notes

56 Divergent Evolution=Adaptive Radiation
One species gives rise to many species More alike to less alike Also known as adaptive radiation. Examples: - Darwin’s Finches. - Brown bears and polar bears Draw this diagram in notes

57 Coevolution Co-evolution occurs when, two or more organisms evolve together.

58 Punctuated equilibrium
Gradual equilibrium predicts that a lot of evolutionary change takes place in short periods of time tied to speciation events. Predicts that little of evolutionary change takes place in small gradual steps.

59 Types of Evolution; ALL

60 Charts to compare evolutionary relationships:
Cladogram: a chart that is composed of many different clades or branches. It is similar to a family tree as it has many different branches, but it is set up in a slightly different format than a typical tree. Organisms listed are all related, but the cladogram depicts the successive points of species divergence from common ancestral lines.

61 Cladogram Example: Which species developed first: Ferns or Mosses?
How long ago was the development of vascular tissue? Assuming this cladogram is correct, would we find a fossil for a fern that is in rock 425 million years old?

62 Charts to compare evolutionary relationships:
Dendrogram – a branching diagram representing a hierarchy of categories based on degree of similarity or number of shared characteristics, especially in biological taxonomy.

63 Dendrogram Example: Who is most closely related to the Brown bear?
Who is furthest related to the Brown bear? Who is most closely related to the Lesser panda?

64 PAP Homework Natural Selection Survival of the Fittest New Species
Change over Time Darwin Dog Breeds Naturalist Anatomical Evidence DNA Galapagos Whale Bones Vestigial Structures Homologous Turtles Finches Shaped Shells


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