Evolution (Part 1)

1
Evolution (Part 1)

• IN 163 165

2
Incorrect Theories of Evolution Lamarck

• Lamarck proposed an incorrect mechanism for how
  organisms evolve
• Simple life forms continually came into existence
  from dead matter
• Continually become more complex
• More "perfect" -- as they transformed into new
  species.
• He correctly pointed out that change in species
  is linked to an organisms environment.

3
Linnaeus (1707-1778)

• Swedish Botanist
• Tried to Classify all of life on earth
• Kingdoms, Classes, Orders, Genera, Species
• He influenced Darwins Theories
• Today we classify life by this order
• Kingdom (Keep)
• Phylum (Pots)
• Subphylum(Sparkling)
• Class (Clean)
• Order (or)
• Family (Food)
• Genus (gets)
• Species (Stuck!)

4
Who Was Charles Darwin

• Label your paper
• Write 5 facts from the short video clip on
  Darwin
• http//www.pbs.org/wgbh/evolution/library/11/2/e_s
  _2.html

5
Darwins Observations

• Animals on the coast of S. America
• Resembled those on the nearby islands
• Evolved differences
• Or
• Descended w/ modification after separating from a
  common ancestor.

6
Left page 126 Figure 16-13 page 406
7
Todays Activity Darwins Great Voyage!!! IN 128
129
http//www.pbs.org/wgbh/evolution/educators/lesson
s/lesson2/act1.html

1. Plot Darwins 17 Stops on map IN 166
2. Mark the date next to each stop
3. List one observation he made at each stop on the
   map

8
Evolution (Part 2)

• IN 169 171

9

• Growth of Populations
• Darwin was influenced by Thomas Malthus
• He wrote
• Populations grow as much as the environment
  allows.

10
Evolution by Natural Selection

• The process of
• Survival of the Fittest
• Organisms that adapt to their environment survive
  while those that do not adapt disappear
• N.S. leads to adaptations in a population.

11
Label Paper

• Genetic Variation
• a.
• b.
• Overproduction of Offspring a.
• b.
• Struggle for Existence a.
• b.
• Differential Survival Reproduction a.
• b.

Natural Selection Video
http//www.pbs.org/wgbh/evolution/library/11/2/e_s
_4.html 6 min 39 sec
12
Darwins Ideas Updated

• 1) Change Within Populations
• N.S. causes the frequency of certain alleles in a
  population to change over time.
• 2) Species Formation
• Under certain conditions, change within a species
  due to reproductive isolation can lead to new
  species.
• 3) The Tempo of Evolution
• Gradualism is a process of evolution in which
  speciation occurs gradually
• Punctuated Equilibrium is a process in which
  speciation occurs rapidly between periods of
  little or no change.

13
(No Transcript)
14
Evidence of Evolution--Formation of Fossils

• Evidence of orderly change can be seen when
  fossils are arranged according to their age.

15
Anatomy and Development

• Vestigial Structures
• Reduced or nonfunctional vestigial structures
• hind limbs in whales
• provide evidence of an organisms evolutionary
  history.

16
Whale Evolution Video Label Paper 1-5
http//www.pbs.org/wgbh/evolution/library/03/4/l_0
34_05.html 5 min, 9 sec
17

• Homologous Structures
• Structures in different organism that indicate a
  shared ancestry
• include vertebrate forelimb.

18
(No Transcript)
19
Evidence of Evolution--
Biological Molecules

• Proteins
• MORE differences in amino acid sequences of
  distantly related species
• LESS differences between species that are more
  closely related.
• Nucleic Acids (what is a nucleic acid???)
• MORE differences in DNA sequences b/t distant
  relatives
• LESS differences between species that are more
  closely related.

20
Examples of Evolution--
Natural Selection at Work

• 1) Factors in Natural Selection
• Organisms w/traits helping them survivereproduce
  pass genes.
• 2) Evolution of Antibiotic Resistance
• Experiments show that evolution through N.S. has
  occurred within populations of antibiotic-resistan
  t bacteria
• Tuberculosis bacteria
• 3) Evolution in Darwins Finches
• Experiments show that evolution through N.S. has
  occurred in beak size in Darwins Finches.

21
Formation of New Species

• 1) Speciation
• Speciation begins as a population adapts to its
  environment.
• 2) Forming Subspecies
• Populations of the same species that differ
  genetically b/c of adaptations to different
  living conditions are called subspecies.
• Newly formed subspecies are on the road towards
  speciation.
• 3) Maintaining New Species
• Reproductive isolation through barriers keeps
  species from breeding with one another.

22
Dichotomous Keys

• Tool used when new species is found
• Used to categorize different species based on
  physical characteristics
• Classification is a way of separating a large
  group of closely related organisms into smaller
  subgroups.
• A Dichotomous Key is a listing of
  characteristics, such as structure and behavior,
  organized in such a way that an organism can be
  identified or classified.