Introduction to Evolution

1
Introduction to Evolution

• Mr. Modafferi
• Biology 9 - Regents

2
Do Now

• How many recorded species are there in the world?
• 1.4 Million Recorded

3
Interesting Fact
Hydrothermal vents along the floor provide a type of chemical energy for bacteria. These bacteria use this energy like plants use the energy of the sun. They then form the base of a giant food web thousands of feet below the surface. Only until recently have we been able to discover this new habitat. Now scientists believe there could be as many as a million species just in on the ocean floor.
4
How is it possible that there are so many
different species?

• The Theory of Evolutionary

5
Evolution

• The genetic changes in organisms over time
• This explains how modern organisms have descended
  from ancient organisms
• Occurs in populations of organisms, not
  individuals
• Evolution is one of the great unifying theories
  of biology

6
Scientific Theory

• Statements or models that have been tested and
  confirmed many times
• THERE IS NO DOUBT IN THEORIES
• Theory is almost as good as fact because it has
  been tested and retested by many people.

7
Properties of Theories

• They explain a wide variety of data and
  observations
• They can be used to make predictions
• They are not absolute, they serve as a model of
  understanding the world and can be changed as the
  world view changes

8
Question of the Day

• How did organisms change over time (evolve)?
• How is a Giraffes neck longer now than it was in
  the past?

9
Lamarcks Hypothesis of Evolution

• Lamarck (1744-1829)
• 1)Believed that species would gain or lose
  features if they overused or didnt use them
• - They adapted to their environment
• 2)Inheritance of acquired characteristics
• - Lamarck believe that organisms become adapted
  to their environment during their lifetime and
  pass on these adaptations to their offspring

10
Use and Disuse - Explained

• New structures arise because they are needed
• Structures already present become better
  developed due to frequent use
• Structures that are not used decrease in size and
  eventually disappear

11

• A giraffe stretched its neck to reach higher
  leaves, and this stretched neck would be a trait
  inherited by its offspring

12
Lamarcks Theory Was Proven Wrong!
13
Think Logically

• If you had a terrible accident and one of your
  limbs got amputated would your offspring not have
  that limb when born?

14
Who is the main man of evolution?

• Charles Darwin
• Born February 12, 1809
• The main contributor to the modern theory of
  evolution
• He wrote The Origin of Species in 1859

15
Charles Darwin

• Darwin made many observation and collected
  different specimens during his five-year journey
  on the Beagle.
• Please take out your map of Darwins journey and
  lets discuss some of his observations!

16

• Darwin's many observations led him to the idea
  that species slowly change over time
• Darwin's comparison of the animals of South
  America and the Galapagos Islands caused him to
  conclude that adaptation to the environment can
  cause diversification, including origin of new
  species
• Examples Patagonian hares replaced rabbits in
  the South American grasslands

17
Please Take Out a Piece of Paper

• Write Down
• 3 things you learned
• 2 things you found interesting
• 1 thing you still dont understand or one
  question you still have

18

• Plato Aristotle believed species were fixed
  could be arranged according to their complexity
• In the mid eighteenth century, Carolus Linnaeus
  developed a system of classification that called
  binomial nomenclature
• George Cuvier, in the eighteenth century,
  explained changes in the fossil record by
  proposing that a whole series of catastrophes
  (extinctions) and re-populations from other
  regions had occurred giving the appearance of
  change over time
• Prior to Darwin, it was thought that the world
  was young species did not change