Card Set Information
1831- Done w theology school
Naturalist on HMS Beagle 1831-1836 (5 years)
Galapagos islands (off pacific s america) 6 weeks
: toroises, mocking birds, finches, cacti, etc...
Came home- thought/writing/reading/communication
Charles lyell 1830 geology (earth is old)
Essay of 1842
Got a letter from naturalist Alfred Russell Wallace
July 1st 1858 - joint papers given by wallace and by darwin
Published "origin of species"
Ideas- world is not static, it is changing
Change could be spoken as "evolving"
Evolution is "Gradual"
Natural selection is a process / results in evolution
Phenotype / Genotype:
Group of organism, interbreeding, in 1 area, in 1 species
at the genes in a population
biotic factors - Living
abiotic factors - non living
Natural Selection -
Differential perpetuation (survivial/reprodcution) of genotypes
(some genotypes do better than others)
1. organisms can reproduce sexually
2. there is inheritable variation
3. testing of organisms by environment
EXAMPLE OF NATURAL SELECTION:
: digging abilities
FF Ff ff
Foxes eat ff --> FF Ff
Example of natural selection - some genotypes have done better than others.
: Before: F 3/6 f 3/6
: F 3/4 f 1/4
Change in allele frequencies:
Natural Selection is a process and results in microevolution
Types of NS: stabilizing NS
1. Stabilizing N.S.
: human birth weight
Those on ends of curve are at a disadvantage
individuals at one end of the curve are at an advantage at other end they are at a disadvantage.
: squirrels w longer fur survive through winter
: increased resistance to antibiotics in bacteria
: Plants around mine tailings
: moth coloration: Melanistic moths *industrial melanism)
Pre 1850- moths were light, mostly
Post 1850- many moths are dark
Any function or structure that produces better adjustment of organism to environment.
Natural selection (process)---> adaptation
Change in allele frequencies through time
(NS) process ----> microevolution
2 or more species interacting, and they are selective force on other. (deer and wolves)
1. origin - mutation
2. How is it observed / quantified?
a) morphological variation (ex flower color)
b) enzyme variabilty -
allozymes- alternate forms of an enzyme
-coded for by same locus
-gel electrophoresis may tell them apart
: heterozygosity - % loci heterozygous in an individual (humans 7%)
: polymorphism - % loci polymorphic in an population (humans 38%)
c) variation in DNA - more vairabilty in dna than in enzymes.
aa - diff codons --- variability
d) eq of variabilty - hemoglobin molecule (sickle cell anmenia)
Higher in africa - carrier for sickle cell - immune to malaria
Arguments for variability: