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32. EVOLUTION AND SPECIATION - Coggle Diagram
32. EVOLUTION AND SPECIATION
EVOLUTION
EVOLUTION
IS THE CHANGE IN THE HERITABLE CHARACTERISTICS OF A POPULATION
ACQUIRED CHANGES
THAT ARE NOT GENETIC IN ORIGIN ARE NOT REGARDED AS EVOLUTION
EVOLUTION THEORY IS A
PRAGMATIC TRUTH
BECAUSE IT PREDICTS AND EXPLAINS A BROAD RANGE OF OBSERVATIONS
NATURE OF SCIENCE
MAKES IT IMPOSSIBLE TO PROVE THE THEORY THOUGH
TYPES OF SPECIATION
ALLOPATRIC
THE POPULATIONS LIVE IN
DIFFERENT AREAS
GEOGRAPHICAL ISOLATION
SYMPATRIC
POPULATIONS LIVE IN THE
SAME AREA
TEMPORAL ISOLATION
POPULATIONS OF A SPECIES BREED AT
DIFFERENT TIMES
BEHAVIORAL ISOLATION
POPULATIONS OF A SPECIES HAVE
DIFFERENCES IN BEHAVIOR
THAT PREVENT INTERBREEDING
BOTH ALLOPATRIC AND SYMPATRIC SPECIATION REQUIRE SPECIES TO BE
REPRODUCTIVELY ISOLATED
AND
NATURAL SELECTION
MUST OCCUR
REPRODUCTIVE ISOLATION
FOR SPECIATION TO OCCUR, THE SPECIES NEEDS TO
STOP INTERBREEDING
WITH EACH OTHER
THE
CHIMPANZEE
AND
BONOBO
BECAME REPRODUCTIVELY ISOLATED BY THE
CONGO RIVER
THE 2 SPECIES GOT EXPOSED TO
DIFFERENT SELECTION PRESSURES
, EVOLVING THEM INTO DIFFERENT SPECIES
REPRODUCTIVE ISOLATION CAN BE ACHIEVED BY
GEOGRAPHICAL ISOLATION
BARRIERS TO HYBRIDIZATION
INTERSPECIFIC HYBRIDS
ARE PRODUCED BY BREEDING MEMBERS OF DIFFERENT SPECIES
FOR EXAMPLE THE
MULE
IS PRODUCED BY THE BREEDING OF A
HORSE AND A DONKEY
COURTSHIP BEHAVIOR
IS USED TO CHECK WHETHER A POTENTIAL PARTNER IS A MEMBER OF ITS OWN SPECIES,
PREVENTING HYBRIDIZATION
EVIDENCE FOR EVOLUTION
SEQUENCE DATA
AS
MUTATIONS
OCCUR, THE
NUMBER OF DIFFERENCES BETWEEN BASE SEQUENCES
DEMONSTRATE
EVOLUTIONARY DIVERGENCE
AMINO ACID SEQUENCES
ARE ALSO USED BUT THEY HAVE A LOWER RATE OF CHANGE
SELECTIVE BREEDING
SELECTIVE BREEDING PROVIDES
EVIDENCE OF EVOLUTION
AS BREEDS CAN SHOW
SIGNIFICANT CHANGE
IN A SHORT PERIOD OF TIME
THE WILD MUSTARD CROP PLANT
HAS BEEN BRED TO PRODUCE DIFFERENT PLANTS
DOGS
HAVE BEEN BRED FOR HUNTING, RACING AND SIZE
HOMOLOGOUS STRUCTURES
HOMOLOGOUS STRUCTURES ARE FOUND IN
DIFFERENT SPECIES
AS A CONSEQUENCE OF
COMMON ANCESTRY
FOR EXAMPLE, THE
PENTADACTYL LIMB
. HUMANS USE THEM FOR TOOL MANIPULATION, BATS FOR FLIGHT AND WHALES FOR SWIMMING
THESE ARISE FROM
DIVERGENT EVOLUTION
WHERE RELATED SPECIES EVOLVE DIFFERENT TRAITS DUE TO
SELECTIVE PRESSURES
ANALOGOUS STRUCTURES
ANALOGOUS STRUCTURES ARE FEATURES PRESENT IN DIFFERENT SPECIES THAT HAVE THE
SAME FUNCTION
BUT DID NOT EVOLVE FROM A COMMON ANCESTOR
FOR EXAMPLE, THE
STREAMLINED BODY
SHAPE OF A DOLPHIN (MAMMAL) AND A SHARK (FISH)
THESE ARISE FROM
CONVERGENT EVOLUTION
WHERE DIFFERENT SPECIES OCCUPY THE
SAME HABITAT
AND ARE SUBJECTED TO THE SAME SELECTIVE PRESSURES
ADAPTIVE RADIATION
ADAPTIVE RADIATION
IS THE PATTERN OF DIVERSIFICATION IN WHICH SPECIES FROM A COMMON ANCESTOR, OCCUPY A RANGE OF ECOLOGICAL ROLES
ADAPTIVE RADIATION ALLOWS CLOSELY RELATED SPECIES TO
COEXIST WITHOUT COMPETING
THIS
INCREASES BIODIVERSITY
IN ECOSYSTEMS WHERE THERE ARE VACANT NICHES
SPECIAITON
SPECIATION
IS THE PROCESS OF ONE SPECIES SEPARATING INTO 2
THIS
ADDS TO THE TOTAL NUMBER OF SPECIES
ON EARTH
GRADUAL EVOLUTIONARY CHANGE
DOES NOT ADD MORE SPECIES
EXTINCTION
REDUCES THE NUMNER OF SPECIES
ABRUPT SPECIATION
A
POLYPLOID ORGANISM
HAS MORE THAN 2 SETS OF HOMOLOGOUS CHROMOSOMES
POLYPLOID ORGANISMS CAN
INTERBREED
WITH OTHER POLYPLOID ORGANISMS (WITH THE SAME CHROMOSOME NUMBER)
SMARTWEED
IS AN EXAMPLE AS IT CONTAINS MANY SPECIES THAT HAVE BEEN FORMED BY POLYPLOIDY