EVOLUTION UNIT

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EVOLUTION UNIT

• BIG IDEA
• THE ENVIRONMENT SELECTS THE TRAITS OF ITS
  INHABITANTS.

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Evolution
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Key Vocabulary

• Biogenesis
• All living things come from other living things
• Spontaneous Generation
• States that life can come from nonliving matter
• Evolution
• the development of new types of organisms from
  preexisting organisms over time
•  

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• Natural Selection
• Is the mechanism for descent of modification
• Adaption
• A trait that makes an organism successful in its
  environment
• EX
• thicker fur coats in cold climates
• Fitness
• Is a measure of an individuals hereditary
  contribution to the next generation

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• Homologous Structure
• structures that occur in different species and
  originate from a common ancestor
• Example human arm and whales fin
• Analogous Structure
• Structures that are closely related but do not
  derive from the same ancestor
• Example Wings of butterfly and bird
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• Vestigial Structure
• Structures that serve no function but that
  resemble structures with functional roles
• Example Human appendix

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• Fossil
• Are the remains of an organism that died long ago
  
• EX
• Dinosaur bones
• Control Group
• the group that doesnt change
• Experimental Group
• the group that has the variable

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Whats a Theory?

• A theory summarizes a hypothesis that has been
  supported
• It is accepted as long as there is NO evidence to
  disagrees with it
• So. Theories can be disproven

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Big Bang Theory

• 15 billion years ago
• HUGE explosion that started the expansion of the
  universe
• This explosion ? BIG BANG!!!!
• It is thought that the explosion was more inward
• It laid the foundation of the universe

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DO NOW Where does life come from?
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17th century

• A piece of meat was left out.
• The next day flies and maggots were seen on the
  meat.
• Where did the flies come from?
• The thought? the meat.

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Spontaneous Generation

• idea that life can arise from nonliving matter.
• There is a life force

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Scientists that Disprove Spontaneous Generation

• Francesco Redi
• Lazzaro Spallanzani
• Louis Pasteur

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Francesco Redi

• 1668
• Francesco Redi
• One scientist that performed an experiment that
  disproved spontaneous generation

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Redis Experiment

• Control group
• Put meat in a jar uncovered.
• Experimental group
• Put meat in a jar covered.

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Procedure

• He let the jars sit out for a couple days
• Observes

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Results.

• Experimental Group

• Control Group

• Flies found on the meat.

• No flies on the meat.

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So.

• Conclusion?
• Flies do not come from the meat.

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Lazzaro Spallanzani

• Italian scientist
• 1768
• Performed another experiment that disprove
  spontaneous generation

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Spallanzanis Experiment

• Control Group
• Boil broth
• Left flask open
• Experimental Group
• Boil broth
• Sealed flask

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Results

• Control
• Broth becomes cloudy
• bacteria present
• Experimental
• Broth remains clear
• NO bacteria

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Conclusion

• The bacteria came from the air

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Louis Pasteur

• French chemist
• He disproved spontaneous generation
• Invented the Pasteurization method

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Pasteur Experiment

• 1862
• Boil broth in a curved-neck flask.
• Curved-neck trapped large particles from getting
  into the body of the flask.

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Experiment

• Control?
• The neck on the flask was not broken
• Experimental ?
• The neck on the flask was broken

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Results

• After a year,
• Broth in the not broken neck of flask ? clear
• Broth in the broken neck of flask ? cloudy

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Conclusion

• Bacteria came from the outside air.

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Biogenesis

• All living things come from the reproduction of
  other living things.

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Evolutionary Thought

• Ch. 15
• Theories of Evolution

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What is evolution?

• Change in an organism over time.

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2 Founders of Evolutionary Thought

• Jean Baptiste Lamarck
• Charles Darwin

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Jean- Baptiste Lamarck

• French Biologist
• Famous for his evolutionary theory of inheritance

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Lamarcks Theory

• 1809
• Two Theories
• Use and Disuse
• Inheritance of Acquired Characteristics

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1. Use and Disuse Theory

• Body parts that are used more grow stronger and
  bigger
• USE
• Body parts that are NOT used deteriorate
• DISUSE

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2. Inheritance of Acquired Characteristics Theory

• Physical traits that were changed in an organism
  are inherited by their offspring(s).

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Lamarck's Example

• Giraffes neck
• They gets longer as it stretches to reach food in
  trees.

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Is Lamarck correct????

• NO!!!!!!

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According to genetics

• Variations that occur in the
• GAMETES cells are passed to offspring
• SOMATIC (body) cells are NOT inherited

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Charles Darwin

• British Naturalist
• Set sail on the HMS Beagle
• Famous for his studies with finches on the
  Galapagos Islands
• Father of Evolution

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Darwins Finches

• Went to the Galapagos Islands
• He observed different types of finches
• These observation lead to him developing his
  theory of evolution

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Alfred Wallace

• British Naturalist
• Co discover of natural selection
• Wallace and Darwin presented their ideas to the
  public
• Darwinism

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Darwin-Wallaces Theory

• States
• Descent with modification
• Evolution occurs by the process of natural
  selection.

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1. Descent of Modification

• states evolution is the development of new
  organisms from preexisting organisms over time.

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2. Natural Selection

• Over production
• In a population, more offspring are produced than
  can survive.
• Competition
• Only some survive long enough to reproduce.

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3. Variation

• There is variation within a population
• these variations are inherited and lead to
  differences in organisms

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4. Adaptation

• traits that are favorable and improve the
  organisms ability to function and reproduce.

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5. Survival of the Fittest

• States that survivors pass on their variations.
• Therefore..
• a larger proportion in the next generation will
  have those variations.

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6. Fitness (in evolution sense)

• is a measure of an individuals genetic
  contribution to the next generation.

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7. Speciation

• Over time, small changes accumulate and
  populations change.

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8. Species

• a group of organisms that can mate and produce
  fertile offspring.

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Evolutionary Theories
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LaMarcks Theory

• Organisms constantly strive to improve themselves
  and become more advanced
• This effort causes the most used body structures
  to develop,
• while unused structures waste away
• AKA? Used/Disused Theory

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LaMarck Theory (2)

• Once a structure is modified,
• It is inherited by the organisms offspring
• Think about the muscles used by a runner

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Darwins Theory

• There is always a variation amongst a population.
  
• Many variations are inherited and passed on to
  offspring
• However,
• some are more favorable
• Improve organisms survival in the environment

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Darwins Theory (2)

• More young are produced in each generation than
  can survive
• Organisms that survive and reproduce are those
  with favorable characteristics

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Wallaces Theory

• He came to the same conclusions as Darwin did

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Goulds Theory

• American Evolutionist
• He came up with Punctuated Evolution
• Which defines the way of evolutions pace

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Punctuated Evolution

• species remain the same for extended periods of
  time
• then small changes occur

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Punctuated Equilibrium

• States that for long periods of time, the
  existing species didnt change ? Equilibrium
• Then, in relatively short periods of time, there
  is an interruption in the equilibrium
• New species emerge.

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Gradualism

• Evolution that occurs slowly and continuously
  throughout time

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Evolution to a New Species
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2 Theories for New Species

• Lamarcks Theory
• Darwins Theory

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Lamarcks Theory New Species (1)

• The environment changes
• Which creates a need for organisms to change
• Organisms develop new features which are passed
  down to offspring

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Lamarcks Theory New Species (2)

• Newly acquired traits somehow get passed down to
  offspring
• New species ? eventually evolves

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Darwins Theory New Species (1)

• Variations are inherited
• Environment
• selects features for survival
• eliminates unfavorable traits

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Darwins Theory New Species (2)

• Those traits which
• help survival tend to survive
• Those organisms have more offspring
• Therefore..New species

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Evidences of Evolution
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Evidence

1. Fossil Evidence
2. Anatomy
3. Embryology
4. Molecular Evidence

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1. Fossil Evidence

• Fossils
• remains/trances of organisms that died long ago
• They are often found in strata
• Strata? layered rock

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1.Fossil Evidence (2)

• If undisturbed,
• the lowest stratum is the oldest
• the highest stratum is the newest
• Relative Age
• found by comparing ages of strata
• Absolute age
• found by using radiometric dating

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• Fossil record suggests that different species
  were present in the past than today.

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• Gradualism
• Fossil record should show many transitional
  species,
• they DONT
• Punctuated Equilibrium
• Fossil records seem to support this
• However, the mechanism is uncertain

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2. Anatomy

• studies the parts or structures of living things.

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Homologous Structures

• Similar internal parts
• Different function in different organisms
• This suggests descended from COMMON ANCESTORS
• Ex
• Human arm
• Cat leg
• Whale fin
• Bat wing

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What do you notice?
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Analogous Structures

• Similar external form and function
• Different internal forms and function
• Suggests species came from DIFFERENT ancestral
  lines
• Ex
• Bat Wing
• Bird Wing
• Insect Wing

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What do you Notice?
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3. Embryology

• study of embryos as they develop
• Similarities of the development of embryos
• suggests that the species have a common ancestor

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4. Molecular Evidence

• when we analyze chemical similarities between
  organisms
• Ex
• DNA Comparison
• Protein Comparison

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A. DNA Comparison

• The more DNA is similar the CLOSER the
  relationship between the organims

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B. Protein Comparison

• Amino acids
• The building blocks of proteins
• Similarities of amino acids that make proteins
  suggest a relationship between organisms
• EX
• In proteins the difference between amino acids
• Humans vs. monkeys ? 1 difference
• Human vs. pigs ? 10 differences