Download Review 10 ••How does one know if natural selection is occurring

Review 10
••How does one know if natural selection is occurring?••
POPULATION GENETICS--the study of the genetics of entire
populations, not just family lines (Mendelian genetics)
e.g. distribution of phenotypes within a population
frequency of occurrence of alleles within a population
Hardy-Weinberg equation:
p2 + 2pq + q2 = 1
p+q=1
p = frequency of one allele
q = frequency of the other allele
• if know p and/or q, can predict frequency of occurrence of
various phenotypes within the population by plugging
numbers into the equation
• if know frequency of occurrence of phenotypes (esp.
homozygous recessive), can compute frequencies of alleles (p
and q) as follows:
Models for origins of the universe, life and diversity.
Evolution: accumulation of adaptive change over time resulting in
formation of new species.
Microevolution = accumulation of small adaptive changes
Macroevolution = formation of new species (speciation)
Phyletic speciation: accumulation of change within a lineage over time
 Look in fossil record for series of changes over time
Allopatric speciation: separation of sub-populations with accumulation
of different changes within different groups over time
 Look for common ancestors in fossil record
What we find in the fossil record: long periods of little change
punctuated by short periods of great change:
Punctuated Equilibrium--long periods of stasis interrupted by
rapid bursts of extinction and/or modification
Review 10, con’t
Summary of evolution model:
time
time
time
time
random ---> structured ---> living ---> complex ---> present
matter
matter
matter
organisms
diversity
(big bang) (universe, etc.) (prok.)
(euk.)
**OCCURS AS RESULT OF NATURALISTIC FORCES OVER TIME**
Creation (or Intelligent Design):
creator
nothing----->present diversity
**OCCURS AS RESULT OF CREATIVE ACTS OF CREATOR (INTELLIGENT DESIGNER)**
Science:
deals with the tangible; that which can be seen, measured, heard,
felt, smelled, etc.
scientifically valid models are testable
problem with creation science is that it’s not very testable!
Both models:
✑ derive from similar bodies of information
✑ rely on elements of faith which haven’t yet been proven
(evolution: eternal existence of matter and energy; creation:
creator)
✑ make certain predictions (e.g. age of universe and earth,
mutation rates, nature of fossil record)
✑ research on evolution model guided by present scientific
understanding of observations of the world around us
✑ research on creation model often guided by attempts to
disprove evolution model--not a good way to proceed
Theistic Evolution: a valid middle ground?