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Evolution A population changes over time.

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Presentation on theme: "Evolution A population changes over time."— Presentation transcript:

1 Evolution A population changes over time

2 Charles Darwin ( )

3 A. Published Origin of Species in 1859

4 - 22 years old, HMS Beagle - Voyage of 5 years

5 2. Galapagos Islands

6 B. Darwin’s Influences 1. Lamarck (early 1800s)
i. Believed that animals change over time- contrary to popular belief! At least he sees that organisms change- gets a bad rap If you cut a mouse tail off children will still have tail- not changing the genes Characteristics gained after birth – cannot be passed on through reproduction ii. Inheritance of Acquired Characteristics: characteristics can be gained through use and passed on to offspring

7 Kayan “giraffe” women Mountains between Burma and Thailand. Kayan women “Giraffe women” Part of Kayan beauty culture

8 Traits Must be Genetic to Pass On!
You cannot “ force” yourself to have a characteristics Example #1: You cannot force yourself to be lactose tolerant Example #2: Bacteria CANNOT acquire resistance to antibiotics Note: New traits cannot be created during your lifetime Only genes can be passed on

9 2. Lyell HISTORY OF THE EARTH CALENDER is 4.5 Billion years old The other idea was that Earth itself is less than 10,000 Lyell proposed that gradual and observable geologic processes such as erosion could explain the physical features of today's Earth. thousands or millions of years Previously, idea was that Earth itself is less than 10,000 years old Proposed that gradual and observable geologic processes such as erosion could explain the physical features of today's Earth taking place over thousands or millions of years

10 i. Earth 4.5 billion years old
3.5 billion years first life (single celled) Earth 4.5 billion years old 3.5 billion years first life ( single celled)

11 C. Fossils: found on Darwin’s trip.
Shows earth is old – there is enough time for descent with modification to occur Shows earth is old – there is enough time for descent with modification to occur

12 II. Darwin’s Finches A. Biogeography- geographic distribution of life forms Galapagos Islands- Volcanic islands off the coast of South America 1. Species were slightly different than the ones on the mainland C. Finches- different beaks depending on the food available i. Cactus-eating finch:more point beak ii. Insect-eating finch: sharp ( trees) iii. Types of seeds D. All descended from one mainland Finch DESCENT WITH MODIFICATION from a COMMON ANCESTOR

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17 VIDEO: https://www.youtube.com/watch?v=flDL2ZQtK8I
LINK attached VIDEO: https://www.youtube.com/watch?v=flDL2ZQtK8I

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20 The Galápagos tortoise or Galápagos giant tortoise the largest living species of tortoise and 10th-heaviest living reptile, reaching weights of over 400 kg (880 lb) and lengths of over 1.8 meters (5.9 ft). shell size and shape vary between populations- humidity, dryness ect The Galápagos tortoise or Galápagos giant tortoise the largest living species of tortoise and 10th-heaviest living reptile, reaching weights of over 400 kg (880 lb) and lengths of over 1.8 meters (5.9 ft). Shell size and shape vary between populations- humidity, dryness etc.

21 Only swimming marine iguana

22 Galapagos Land Iguana

23 Blue Footed Boobie blue feet and dancing to impress the female.mating ritual Bblue feet and dancing to impress the female.mating ritual

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25 Frigatebird- Do this to distract others and take their prey

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28 III. Natural Selection Definition: mechanism for evolutionary change
Components: Inherited variations: Mutations- changes in DNA Meiosis Struggle for existence Adaptations (traits that help an organism be more suited to the environment) increase survival and reproductive success Reproduction- Genes for adaptations increase in each generation – (Fitness- reproductive success) LACKS DIRECTION – if environment change- not going towards a “BEST” Extinction- previous adaptations are no longer suitable to changed environment

29 IV. Artificial Selection
Breeder choices which traits to perpetuate ( dogs descended from wolves) Canis familiaris comes from canis lupis domesticated 14, 000 years ago Natural selection would never have selected dogs with long ears ( ear infetions) Breeder choices which traits to perpetuate (dogs descended from wolves). Canis familiaris comes from Canis lupis domesticated 14,000 years ago.

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31 The result of Natural Selection is a population adapted to the local environment

32 Evidence for Evolution
A. Fossils B. Biogeographical C. Anatomical D. Biochemical E. Embryology F. Examples- Antibiotic

33 Fossils

34 8 million years ago humans chimpanzees : dozen human-like species called hominids
The modern form of Homo sapiens first appeared about 100,000 years ago. This species is distinguished by large brain size, mouth not as protruding. Begin with bipedal ancestor- skulls begin when humans began to walk on two feet

35 Lucy, after the Beatles song "Lucy in the Sky with Diamonds", which was being played loudly and repeatedly on a tape recorder in the camp.[3]

36 “Lucy” 3.2 million year old hominid fossil Australopithecus afarensis Significant because skeleton shows evidence of small skull capacity like that of apes and of upright bipedal posture like humans

37 B. Biogeography A mammal of an order (Marsupialia) whose members are born incompletely developed and are typically carried and suckled

38 C. Anatomical Evidence 1. Homologous Structure: Structures that are similar because they are inherited from a common ancestor

39 C. Anatomical Evidence 2. Analogous Structures: features are similar in function but not in structure. They do not derive from a recent common ancestor but in response to a similar environment.

40 ANALOGOUS STRUCTURES

41 C. Anatomical Evidence 3. Vestigial structures: no longer have function. occur because organism inherit anatomy from their ancestors. Examples: Some snakes have small hindlimbs Humans: Appendix, wisdom teeth, tail bone

42 THE APPENDIX VESTIGIAL STRUCTURE
we can’t digest cellulose (in leaves, barks of trees VESTIGIAL STRUCTURE

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44 KOALA

45 EUCALYPTUS

46 D. Biochemical Living organisms use DNA, and many identical enzymes (same 20 amino acids) Degree of similarity of DNA sequence or amino acid structure based on how closely related

47 E. Embryology ( Development)
1. Embryos of closely related organisms often have similar stages in development.


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