CHAPTER 14: THE ORIGIN OF THE SPECIES

1
CHAPTER 14 THE ORIGIN OF THE SPECIES
2
MACROEVOLUTION

• DRAMATIC BIOLOGICAL CHANGES
• LARGE-SCALE PATTERNS, TRENDS AND RATES OF CHANGE
  AMONG SPECIES

3

• WHAT IS THE DIFFERENCE BETWEEN MICRO AND
  MACROEVOLUTON?

4

• MICROEVOLUTION INVOLVES CHANGES IN THE GENE POOL
  OF A SINGLE POPULATION
• MACROEVOLUTION INCLUDES THE ORIGIN OF NEW SPECIES

5
HOW DO NEW SPECIES ARISE AND NEW PROPERTIES
EMERGE?

• GEOGRAPHY
• BEHAVIOR
• GENETIC ISSUES

6
WHAT IS A SPECIES?

• TAXONOMY WAYS TO NAME AND CLASSIFY ORGANISMS
• SPECIES ORGANISMS THAT BREED WITH EACH OTHER
  AND PRODUCE FERTILE OFFSPRING BIOLOGICAL
  DEFINITION
• POPULATIONS AND INDIVIDUALS WITHIN A SPECIES CAN
  VARY

7
INDIVIDUALS WITHIN A SPECIES VARY
8
MORPHOLOGICAL SPECIES

• MOST ORGANISMS ARE CLASSIFIED ON OBSERVABLE AND
  MEASURABLE TRAITS
• RELIES ON SUBJECTIVE CRITERIA

9
ECOLOGICAL SPECIES

• IDENTIFIES SPECIES IN TERMS OF THEIR ADAPTATION
  TO PARTICULAR ROLES IN A COMMUNITY
• MAY BE CLASSIFIED BASED ON WHAT THE ANIMALS EAT
  EVEN IF TWO ORGANISMS ARE SIMILAR IN APPEARANCE

10
PHYLOGENIC SPECIES

• A SET OF ORGANISMS WITH A UNIQUE FAMILY HISTORY
• BY COMPARING PHYSICAL CHARACTERISTICS OR DNA
  SEQUENCES

11
REPRODUCTIVE BARRIERS KEEP SPECIES SEPARATE

• TIME OF MATINGS
• HABITAT
• BEHAVIOR
• STRUCTURAL DIFFERENCES BETWEEN ORGANISMS
• GAMETES DONT DEVELOP

12
(No Transcript)
13
GEOGRAPHIC ISOLATION(ALLOPATRIC SPECIATION)

• SEPARATION OF A SINGLE POPULATION FROM OTHER
  MEMBERS OF THE SAME POPULATION
• THE GENE POOL CAN CHANGE NATURAL SELECTION
• REPRODUCTIVE ISOLATION MUST ALSO OCCUR

14
GEOGRAPHIC ISOLATION CAN LEAD TO NEW SPECIES
15
NEW SPECIES CAN ARISE WITH IN THE SAME GEOGRAPHIC
AREA

• FOR EXAMPLE, ACCIDENTS IN CELL DIVISION THAT
  RESULTS IN EXTRA CHROMOSOMES
• SYMPATRIC SPECIATION

16
ADAPTIVE RADIATION MAY OCCUR IN NEW OR NEWLY
VACATED HABITATS

• ORGANISMS GO TO NEW AREAS
• ENVIRONMENTAL CHANGES MAY CAUSE EXTINCTION OF
  VARIOUS SPECIES
• THE SURVING ANIMALS MAY DEVELOP INTO NEW SPECIES

17
THE GALAPAGOS ISLAND HAS 14 SPECIES OF RELATED
BIRDS

• DIFFERENT BEAK SHAPE AND SIZE ADAPTED FOR
  DIFFERENT DIETS

18
ADAPTIVE RADIATION ON AN ISLAND CHAIN
19
THE TIMING OF SPECIATION CAN BE GRADUAL

• GRADUALISM MODEL
• DIFFERENCES GRADUALLY APPEAR
• NEW SPECIES EVOLVE GRADUALLY FROM THE ANCESTRAL
  POPULATION
• BIG CHANGES OCCUR BY STEADY ACCUMULATION OF SMALL
  CHANGES

20
THE TIMING OF SPECIATION CAN BE JUMPY

• PUNCTUATED EQUILIBRIUM MODEL
• ABRUPT TIMES OF SPECIATION FOLLOWING PERIODS OF
  LITTLE CHANGE
• EVOLUTION OCCURS IN SPURTS

21
GRADUAL CHANGE CAN ACCOUNT FOR THE EVOLUTION OF
INTRICATE STRUCTURES

• COMLEX STRUCTURES EVOLVED FROM SIMPLER VERSIONS
  HAVING SIMILAR FUNCTIONS

22
(No Transcript)
23
GENES THAT CONTROL DEVELOPMENT ARE IMPORTANT FOR
EVOLUTION

• LOCATION OF WHERE A GENE IS EXPRESSED WILL
  DETERMINE WHAT STRUCTURE IT WILL BECOME
• TIME AND RATE OF GROWTH ARE ALSO IMPORTANT IN
  EVOLUTION

24
CHIMPANZEES AND HUMANS ARE MORE RELATED AS
FETUSES THAN AS ADULTS