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Origins - Microevolution
DNA Review
Building
Blocks of
Evolutionary
Theory –
Population
Growth
Building
Blocks of
Evolutionary
Theory –
Variation
• Morphological
• Physiological
• Behaviorally
Credit: © David Cavagnaro
Potato varieties.
Credit: © Stan Elems
Blood Stars (Henricia leviuscula) showing genetic variation.
Credit: © Dr. Donald Fawcett
Land snails, genetic variation, Hawaii.
Sources of Genetic Variation

Mutation
Crossing over at meiosis I
Independent assortment

Fertilization

Change in chromosome number or


structure
Building
Blocks of
Evolutionary
Theory –
The Gene
Pool
• The sum of all of
the alleles for all
the genes for all
the individuals in
the population
Building
Blocks of
Evolutionary
Theory –
Natural
Selection
Number of
individuals
Directional selection
Number of
individuals
Range of values at time 1
Number of
individuals
Range of values at time 2
Stepped Art
Range of values at time 3
Fig. 16-14, p.249
Number of
individuals
Number of
individuals
Range of values at time 1
Range of values at time 2
Number of
individuals
Stabilizing Selection
Stepped Art
Range of values at time 3
Fig. 16-16, p.250
Number of
individuals
Disruptive Selection
Number of
individuals
Range of values at time 1
Number of
individuals
Range of values at time 2
Stepped Art
Range of values at time 3
Fig. 16-16, p.250
13,730 human births
Fig. 16-17, p.251
Fig. 16-15a, p.249
Rock pocket mice – on dark lava and “regular” desert.
Fig. 16-15b, p.249
lower bill 12 mm wide
lower bill 15 mm wide
Black-bellied seedcracker of Cameroon showing two beak sizes showing
selection for two sedge seed sizes.
Evolution
G enetic
V ariation
Reproduction
L and
T ime
N atural
S election
Hardy-Weinberg Equilibrium
Let “p” be the frequency of the dominant allele
“A” in the gene pool.
Let “q” be the frequency of the recessive allele
“a” in the gene pool.
p + q = 1.0
In a diploid population, individuals are
represented by:
(p + q)2 = 1.0
p2 + 2pq + q2 = 1.0
Click to view
animation.
animation
Hardy-Weinberg Equilibrium
N=20
Red = 15/20 = A_ = p2 + 2pq
White = 5/20 = aa = q2
q2 = 5/20 = 0.25
q = 0.50
p + q = 1.00
p = 1.00 – q
= 1.00 – 0.50
= 0.50
Condition required for
Hardy-Weinberg
Equilibrium
“Violation”: Agents of
Evolutionary (Gene Pool)
change
No mutation
Mutation
Hardy-Weinberg Equilibrium
Mutation:
N=20
Red = 15/20 = A_ = p2 + 2pq
White = 4/20 = aa = q2
q2 = 4/20 = 0.20
q = 0.45
Condition required for
Hardy-Weinberg
Equilibrium
“Violation”: Agents of
Evolutionary (Gene Pool)
change
No mutation
Mutation
Large population
Genetic drift (including
population bottleneck and the
founder effect
Hardy-Weinberg Equilibrium
Population Bottleneck:
N=3
Red = 3/3 = A_ = p2 + 2pq
White = 0/3 = aa = q2
q2 = 0/3 = 0.00
q = 0.0
1.0
AA in five populations
0.5
allele A lost
from four
populations
0
1
5
10
15
20
25
30
35
40
45
50
Generation (25 stoneflies at the start of each)
1.0
0.5
allele A
neither
lost nor
fixed
0
1
5
10
15
20
25
30
35
40
45
Generation (500 stoneflies at the start of each)
50
Fig. 16-22, p.254
Click to view
animation.
animation
Year
Before 1492
Estimated American
bison population
size
60,000,000
1890
750
2000
360,000
http://en.wikipedia.org/wiki/Population_bottleneck
phenotypes of original
population
phenotype of
island population
Founder effect – An albatross has carried seeds to a distant island from the
mainland. Frequencies of the orange flowers were low in the original population.
Condition required for
Hardy-Weinberg
Equilibrium
“Violation”: Agents of
Evolutionary (Gene Pool)
change
No mutation
Mutation
Large population
Genetic drift (including
population bottleneck and the
founder effect
Gene flow
No gene flow
(immigration/emigration)
Hardy-Weinberg Equilibrium
Gene Flow:
IF new seeds enter the
population…
N=23
Red = 15/23 = A_ = p2 + 2pq
White = 8/23 = aa = q2
q2 = 8/23 = 0.35
q = 0.59
Gene flow
Fig. 16-24a, p.255
Fig. 16-24, p.255
Condition required for
Hardy-Weinberg
Equilibrium
“Violation”: Agents of
Evolutionary (Gene Pool)
change
No mutation
Mutation
Large population
Genetic drift (including
population bottleneck and the
founder effect
Gene flow
No gene flow
(immigration/emigration)
Random mating
Nonrandom mating
Hardy-Weinberg Equilibrium
Nonrandom mating:
IF red only fertilizes red…
Red = 15/20 = A_ = p2 + 2pq
p2 = 0.502 = 0.25(20) = 5AA
2pq = 2(0.50)(0.50)
= 0.50(20) = 10Aa
A = p = 20/30 = 0.67
a = q = 10/30 = 0.33
q2 = (0.33)2 = 0.11(20) = 2
Condition required for
Hardy-Weinberg
Equilibrium
“Violation”: Agents of
Evolutionary (Gene Pool)
change
No mutation
Mutation
Large population
Genetic drift (including
population bottleneck and the
founder effect
Gene flow
No gene flow
(immigration/emigration)
Random mating
No natural selection - Gene
doesn’t affect survival or
reproduction
Nonrandom mating
Natural selection
Hardy-Weinberg Equilibrium
Natural selection:
IF insects only see red…
Red = 15/20 = A_ = p2 + 2pq
p2 = 0.502 = 0.25(20) = 5AA
2pq = 2(0.50)(0.50)
= 0.50(20) = 10Aa
A = p = 20/30 = 0.67
a = q = 10/30 = 0.33
q2 = (0.33)2 = 0.11(20) = 2
Peppered Moths (Biston betularia)
Peppered Moths (Biston betularia)
In 1998, Michael E. N. Majerus of the
Department of Genetics at the University of
Cambridge carefully re-examined Kettlewell's
studies, as well as many others that have since
appeared. What he reported, first of all, was that
Kettlewell's experiments, indicating that moth
survival depends upon color-related camouflage,
were generally correct:
" Differential bird predation of the typica and
carbonaria forms, in habitats affected by
industrial pollution to different degrees, is the
primary influence on the evolution of melanism
in the peppered moth."
(P. 116, Melanism - Evolution in Action, M. E.
N. Majerus, Oxford University Press, New
York, 1998). I
http://www.millerandlevine.com/km/evol/Moths
/moths.html
Peppered Moths (Biston betularia)
However, Majerus also discovered that many of Kettlewell's
experiments didn't really test the elements of the story as well as
they should have. For example, in testing how likely light and dark
moths were to be eaten, he placed moths on the sides of tree
trunks, a place where they rarely perch in nature. He also records
how well camouflaged the moths seemed to be by visual
inspection. This might have seemed like a good idea at the time,
but since his work it has become clear that birds see ultraviolet
much better than we do, and therefore what seems wellcamouflaged to the human eye may not be to a bird. In addition,
neither Kettlewell nor those who checked his work were able to
compensate for the degree to which migration of moths from
surrounding areas might have affected the actual numbers of light
and dark moths he counted in various regions of the countryside.
http://www.millerandlevine.com/km/evol/Moths/moths.html
Peppered Moths (Biston betularia)
These criticisms have led some critics of evolution to charge
that the peppered moth story is "faked," or is "known to be
wrong.”
http://www.millerandlevine.com/km/evol/Moths/moths.html
Peppered Moths (Biston betularia)
Neither is true. In fact, the basic elements of the peppered moth
story are quite correct. The population of dark moths rose and fell
in parallel to industrial pollution, and the percentage of dark
moths in the population was clearly highest in regions of the
countryside that were most polluted. As Majerus, the principal
scientific critic of Kettlewell's work wrote, "My view of the rise
and fall of the melanic form of the peppered moth is that
differential bird predation in more or less polluted regions,
together with migration, are primarily responsible, almost to the
exclusion of other factors." (p. 155).
http://www.millerandlevine.com/km/evol/Moths/moths.html
Origins – Speciation or
Macroevolution
Fig. 16-5a, p.40
Fig. 16-5b, p.240
route of
Beagle
EQUATOR
Galapagos
Islands
Fig. 16-5c, p.241
Darwin
Wolf
Pinta
Marchena
Genovesa
Santiago
Fernandina
EQUATOR
Bartolome
Seymour
Rabida
Blatra
Pinzon
Santa Cruz
Santa Fe
Tortuga
Isabela
San Cristobal
Espanola
Floreana
Fig. 16-5d, p.241
Darwin, Charles. 1859. On the Origin
of Species by Means of Natural
Selection, or the Preservation of
Favoured Races in the Struggle for
Life
(Quotations that follow are from: Darwin, C. 1872.
The Origin of Species by means of Natural
Selection, or the Preserving of Favored Races in the
Struggle for Life. Edited and Abridged by C. Irvine
and W. Irvine. Frederick Ungar Pub. Co., New
York.)
On the Origin of Species
Chapter 1 - Variation Under Domestication
Believing that it is always best to study some special
group, I have, after deliberation, taken up domestic
pigeons. I have kept every breed which I could purchase
or obtain, and have been most kindly favoured with
skins from several quarters of the world. Many treatises
in different languages have been published on pigeons,
and some of them are very important, as being of
considerably antiquity. I have associated with several
eminent fanciers, and have been permitted to join two of
the London Pigeon Clubs.
On the Origin of Species
The diversity of the breeds is something astonishing.
Compare the English carrier and the short-faced tumbler,
and see the wonderful difference in their beaks, entailing
corresponding differences in their skulls. The common
tumbler has the singular and strictly inherited habit of
flying at a great height in a compact flock, and tumbling
in the air head over heels. The pouter has a much
elongated body, wings, and legs; and its enormously
developed crop, which it glories in inflating, may well
excite astonishment and even laughter.
On the Origin of Species
The turbit has a very short and conical beak, with a line
of reversed feathers down the breast; and it has the habit
of continually expanding slightly the upper part of the
oesophagus. The trumpeter and laugher, as their names
express, utter a very different coo from the other breeds.
The fantail has thirty or even forty tail-feathers. Several
other less distinct breeds might have been specified.
On the Origin of Species
On the Origin of Species
Chapter 2 - Variation Under Nature
The many slight differences which appear in the
offspring from the same parents, may be called
individual differences. These are of the highest
importance for us, as they afford materials for natural
selection to accumulate, in the same manner as man can
accumulate in any given direction individual differences
in his domesticated productions.
On the Origin of Species
These individual differences generally affect what
naturalists consider unimportant parts; but I am
convinced that the most experienced naturalist would be
surprised at the number of the cases of variability, even
in important parts of structure, which he could collect
on good authority, as I have collected, during a course
of years.
Here is what Darwin knew about the
cause of “individual differences”
(genetics…)
…nothing
1859: Darwin Publishes, On the Origin of Species by
Means of Natural Selection, or the Preservation of
Favoured Races in the Struggle for Life
1865: Mendel read his paper, "Experiments on Plant
Hybridization", at two meetings of the Natural
History Society of Brünn in Moravia in 1865. When
Mendel's paper was published in 1866 in
Proceedings of the Natural History Society of Brünn,
it had little impact and was cited about three times
over the next thirty-five years.
(http://en.wikipedia.org/wiki/Gregor_Mendel)
On the Origin of Species
Chapter 3 - Struggle for Existence
How do varieties, species, and genera originate? From
the struggle for life. Owing to this struggle, variations,
if they be in any degree profitable to individuals, will
tend to the preservation of such individual, and will
generally be inherited by the offspring. The offspring,
also, will thus have a better chance of surviving, for, of
the many individuals born, but a small number can
survive. I have called this principle, by which each
slight variation, if useful, is preserved, Natural
Selection, in order to mark its relation to man’s power of
selection. But the expression often used by Mr. Herbert
Spencer of the Survival of the Fittest is more accurate,
and is sometimes equally convenient.
On the Origin of Species
Nothing is easier than to admit in words the truth of the
universal struggle for life, or more difficult constantly to
bear this in mind. We behold the face of nature bright
with gladness, we often see superabundance of food; we
do not see, or we forget, that the birds which are idly
singing round us mostly live on insects or seeds, and are
thus constantly destroying life; or we forget how largely
these songsters, or their eggs, or their nestlings are
destroyed by birds and beasts of prey.
…I use the term Struggle for Existence in a large and
metaphorical sense, including dependence of one being on
another, and including (which is more important) not only
the life of the individual, but success in leaving progeny.
On the Origin of Species
It is the doctrine of Malthus applied with manifold force
to the whole animal and vegetable kingdoms; for in this
case there can be no artificial increase of food, and no
prudential restraint from marriage.
Every organic being naturally increases at so high a rate,
that, if not destroyed, the earth would soon be covered by
the progeny of a single pair. Even slow-breeding man has
doubled in twenty-five years, . . . We may confidently
assert, that all plants and animals are tending to increase at
a geometric ratio. Lighten any check, mitigate the
destruction ever so little, and the number of the species
will almost instantaneously increase to any amount.
Thomas Malthus
1766 - 1834
Malthus, T. 1826. An Essay on the
Principle of Population: A View of
its Past and Present Effects on
Human Happiness; with an Inquiry
into Our Prospects Respecting the
Future Removal or Mitigation of
the Evils which It Occasions, 6th
edition. John Murray, London (First
edition, 1798)
http://en.wikipedia.org/wiki/
Thomas_Malthus
Thomas Malthus
In an inquiry concerning the improvement of
society, the mode of conducting the subject
which naturally presents itself, is,
1. To investigate the causes that have hitherto
impeded the progress of mankind towards
happiness; and,
2. To examine the probability of the total or
partial removal of these causes in future.
Thomas Malthus
It may safely be pronounced, therefore, that
population, when unchecked, goes on doubling
itself every twenty-five years, or increases in a
geometrical ratio.
It may be fairly pronounced, therefore, that,
considering the present average state of the earth,
the means of subsistence, under circumstances
the most favourable to human industry, could not
possibly be made to increase faster than in an
arithmetical ratio.
On the Origin of Species
Chapter 4 - Natural Selection, or the Survival of the
Fittest
Isolation is important in the process of natural selection.
In a smaller confined area conditions will be almost
uniform; so that natural selection will tend to modify
individuals of the same species in the same manner.
Intercrossing with the individuals of the surrounding
districts will also be prevented. After any physical change
in conditions such as of climate, elevation of the land, etc.,
isolation prevents the immigration of better adapted
species; and thus new places will be left open to
modification of the old inhabitants. Lastly, isolation will
give time for a new variety to be improved at a slow rate.
On the Origin of Species
Natural selection will act very slowly, only at long
intervals of time, and generally on only a very few of
the inhabitants of the same region at the same time.
These slow, intermittent results accord well with what
geology tells us of the manner at which the inhabitants
of this world have changed. As favoured forms increase,
the less favoured forms decrease and become rare, and
rarity, as geology tells us, is the precursor to extinction.
On the Origin of Species
According to my view, varieties are species in the
process of formation, or are, as I have called them,
incipient species. How, then, does the lesser difference
between varieties become augmented into the greater
difference between species? Mere chance, as we may
call it, might cause one variety to differ in some
character from its parents, and the offspring of this
variety again to differ from its parent in the very same
character and in a greater degree; but this alone would
never account for so habitual and large a degree of
difference as that between the species of the same
genus.
Ernst Mayr
1904-2005
In his book Systematics and the
Origin of Species (1942) he wrote
that a species is not just a group of
morphologically similar
individuals, but a group that can
breed only among themselves,
excluding all others.
http://en.wikipedia.org/wiki/Ernst_Mayr
Prezygotic Isolating Mechanisms







Ecogeographic isolation
Habitat/Ecological isolation
Temporal variation
Behavioral variation (animals only!)
Mechanical
Sperm/female or Pollen/stigma
incompatibility
Gamete isolation
Temporal isolation in 17 and 13 year cicada species
Fig. 17-17c, p.272
Reproductive behaviors
Fig. 17-17b, p.272
Mechanical
isolation in the
pollinators of
orchids
Fig. 17-17a, p.272
Postzygotic Isolating Mechanisms



Developmental isolation
Hybrid inviablilty
Hybrid sterility
Credit: © Michele Burgess/Visuals Unlimited
Zebroids, hydrids between horse and zebra.
Speciation


Allopatric
Sympatric
Large Cactus Finch
Geospiza conirostris
Common Cactus-Finch
Geospiza scandens
Fig. 16-7b, p.243
Medium Ground Finch
Geospiza fortis
Credit: © Gerald and Buff Corsi
Galapagos Medium Ground Finch (Geospiza fortis), Isabela Island, Galapagos.
Warbler Finch
Certhidea olivacea
Woodpecker Finch
Camarhynchus pallidus
Origins –Spontaneous Generation
and Abiogenesis
Spontaneous Generation
According to Aristotle it was a readily observable
truth that aphids arise from the dew which falls on
plants, fleas from putrid matter, mice from dirty hay,
and so forth. In the 17th century such assumptions
started to be questioned; such as that by Sir Thomas
Browne in his Pseudodoxia Epidemica. His
conclusions were not widely accepted, e.g. his
contemporary, Alexander Ross wrote: "To question
this (i.e., spontaneous generation) is to question
reason, sense and experience. If he doubts of this let
him go to Egypt, and there he will find the fields
swarming with mice, begot of the mud of Nylus, to
the great calamity of the inhabitants.”
http://en.wikipedia.org/wiki/Spontaneous_generation
Spontaneous Generation
“In seventeenth-century London,
Samuel Pepys set down in his now
famous diary the following entry:
“23rd. In my black silk suit (the
first day I put it on this year) to my
Lord Mayor’s by coach, with a great
deal of honorable company, and
great entertainment. At table, I had
very many good discourse with Mr.
Ashmole wherein he did assure me
that many insects do often fall from
the sky, readily formed”
Teale, E. W. 1976. The American Seasons. Dodd,
Mead, New York.
1633 - 1703
http://www.pepys.info/
Spontaneous Generation
“And so they do -- not because they are generated in
the atmosphere as men of Pepy’s day believed, but in
accordance with the simple rule that what goes up
must come down. Swept aloft by powerful updrafts,
even wingless species are sometimes carried far.
During summer months, there is a continual floating
population in the air and a constant rain of life from
the sky. Especially is this true among the
mountains.”
Teale, E. W. 1976. The American Seasons. Dodd, Mead, New York.
Spontaneous Generation
Meat in a
closed
container –
Nothing
happens
Meat in a
screened in
container –
Nothing
happens
Meat in an open
container –
Maggots
happen!
Francesco Redi
1626 - 1697
http://en.wikipedia.org/
wiki/Francesco_Redi
Spontaneous Generation
Louis Pasteur
1822 - 1895
http://en.wikipedia.org/
wiki/Louis_Pasteur
Abiogenesis
Raw
MaterialsMonomers Polymers Protocells Cells
monosaccharides carbohydrates
And
fatty acids
lipids
Energy
amino acids
proteins
purines/
pyrimidines
nucleotides and
nucleic acids
Abiogenesis – Different Conditions
Matter: methane,
A. I. Oparin
1894 - 1980
http://en.wikipedia.org/
wiki/Oparin
ammonia, hydrogen,
and water; carbon
monoxide, carbon
dioxide, nitrogen
Energy: heat,
electricity, uv radiation
Abiogenesis – Testing Oparin
Stanley Miller
1930 -
electrodes
to
vacuum
pump
CH4
NH3
H 2O
H2
spark
discharge
gases
water out
condenser
water in
water droplets
boiling water
water containing
organic compounds
liquid water in trap
Fig. 18-3b, p.289
Yields of amino acids obtained from sparking a mixture of CH4, NH3, H2O and H2.
Table 3-2 from Thaxton, C. B., W. L. Bradley and R. L. Olsen. 1984. The Mystery of
Life’s Origin: Reassessing Current Theories. Philosophical Library, N.Y., NY.
Compound
Yield
(mM)
Compound
Yield
(mM)
Glycine
440
a,g-Diaminobutyric acid
33
Alanine
790
a-Hydroxy-g-aminobutyric acid
74
a-Amino-n-butyric acid
270
Sarcosine
55
a-Aminoisobutyric acid
30
N-Ethylglycine
30
Valine
19.5
Norvaline
61
Isovaline
5
Leucine
11.3
N-Propylglycine
2
N- Isopropylglycine
2
N -Methylalanine
N-Ethylalanine
15
< 0.2
Isoleucine
4.8
b-Alanine
Alloisoleucine
5.1
b-Amino-n-butyric acid
0.3
Norleucine
6.0
b-Amino-isobutyric acid
0.3
g-Aminobutyric acid
2.4
tert-Leucine
< 0.02
18.8
Proline
1.5
N-Methyl-b-alanine
5
Aspartic acid
34
N-Ethyl-b-alanine
2
Glutamic acid
7.7
Pipecolic acid
Serine
5.0
a,b-Diaminopropionic acid
6.4
Threonine
0.8
Isoserine
5.5
Allothreonine
0.8
(From S. Miller, 1974. Origins of Life 5,139.)
0.05
Yields of organic compounds obtained from sparking a mixture of CH4, NH3, H2O and
H2. Table 3-3 from Thaxton, C. B., W. L. Bradley and R. L. Olsen. 1984. The Mystery
of Life’s Origin: Reassessing Current Theories. Philosophical Library, N.Y., NY.
Compound
Relative Yield*
Formic acid
1000
Glycine
270
Glycolic acid
240
Alanine
146
Lactic acid
133
b-Alanine
64
Acetic acid
64
Propionic acid
56
Imiriodiacetic acid
24
Sarcosine
21
a-Amino-n-butyric acid
21
a-Hydroxybutyric acid
21
Succinic acid
17
Urea
9
Iminoaceticpropionic acid
6
N-Methyl urea
6
N-Methylalanine
4
Glutamic acid
3
Aspartic acid
2
a-Aminoisobutyric acid
0.4
(After S. Miller, 1974. Origins of Life 5, 139.)
Biologically relevant amino acids are
shown in bold.
*Yields are relative to formic acid and
presented in descending order.
Harada and Fox results of heating CH4, NH, and H2O at 950°C in the presence of
quartz sand catalyst. Table 3-4 from Thaxton, C. B., W. L. Bradley and R. L. Olsen.
1984. The Mystery of Life’s Origin: Reassessing Current Theories. Philosophical
Library, N.Y., NY.
Amino Acid
Aspartic acid
Percent Yield*
3.4
Threonine
0.9
Serine
2.0
Glutamic acid
4.8
Proline
2.3
Glycine
60.3
Alanine
18.0
Valine
2.3
Alloisoleucine
0.3
Isoleucine
1.1
Leucine
2.4
Tyrosine
0.8
Phenylalanine
0.8
a-Aminobutyric acid
0.6
b-Alanine
Sarcosine
N-Methylalanine
?
From K. Harada and S. Fox, 1964. Nature
201, 335.) Biologically relevant amino
acids are shown in bold.
*Basic amino acids were not fully studied,
and therefore were not listed. Yield is
based on percent of total amino acid
product.
Abiogenesis – The Role of Clay
Graham Cairns-Smith
1931 -
Clay templates in tidal flats
Fig. 18-4a, p.290
Iron sulfide-rich rocks at hydrothermal vents
Fig. 18-4b, p.290
Abiogenesis– Proteinoid Microspheres
Sidney W. Fox
1912 - 1998
p.286b
RNA-coated clay (red) surrounded by a membrane of
fatty acids and alcohols (green)
Fig. 18-5b, p.291
Abiogenesis
Oparin
Miller
Cairnes-Smith Fox
Raw
MaterialsMonomers Polymers Protocells Cells
monosaccharides carbohydrates
And
fatty acids
lipids
Energy
amino acids
proteins
purines/
pyrimidines
nucleotides and
nucleic acids
A strand of what
may be a walled
prokaryotic cells
dating back 3.5
billion years.
Fig. 18-6a, p.292
DNA
Current Nitrobacter
infolding of plasma membrane
Fig. 18-8a, p.294
Theoretical Model of formation of
nuclear membrane and
endoplasmic reticulum
Fig. 18-8b, p.294
Cyanophora paradoxa
Fig. 18-9b, p.295
Endosymbiosis?
photosynthetic organelle that
resembles a cyanobacterium
mitochondrion
nucleus
Cyanophora paradoxa contains mitochondria that resemble aerobic
bacteria. It’s photosynthetic structures resemble cyanobacteria.
Fig. 18-9a, p.295
hydrogen-rich anaerobic atmosphere
atmospheric oxygen, 10%
archaean
lineage
d
ancestors of
eukaryotes
h
endomembrane
system and nucleus
cyclic pathway
of photosynthesis
e
a
noncyclic pathway
of photosynthesis
f
b
origin of
prokaryotes
3.8 billion
years ago
g aerobic respiration
3.2 billion
years ago
2.5 billion
years ago
Fig. 18-10a, p.296
Fig. 18-10b, p.297
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson. 1984.
The Mystery of Life’s Origin: Reassessing Current
Theories. Philosophical Library. New York.
A. Early Atmosphere Problems
B. Prebiotic Soup Problems – Energy would have destroyed the
components of the early atmosphere and any monomers that
would have formed.
C. Prebiotic Soup Problems - Fatty acids and phosphates would
have precipitated when combined with calcium and
magnesium salts. Hydrocarbons and organic nitrogen
containing compounds would adsorb on sinking clay particles.
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
D. Polypeptide Problems.
1. Chemicals other than amino acids are formed.
2. Amino acids other than the biologically important ones are
formed.
3. Both D and L amino acids are produced.
4. The proper bonds are needed between amino acids.
5. Hydrolysis of amino acids and polypeptides.
6. The proper sequence of amino acids is needed.
7. The proper length of amino acids is needed.
8. Termination of polypeptides and polynucleotides.
F. Configurational entropy.
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Alternative Views on the Origin of Life:
A. New Natural Laws
B. Panspermia- A life spore was driven to earth from somewhere
else in the cosmos by electromagnetic radiation pressure.
“Panspermia is the classic extraterrestrial view which originated
after Pasteur’s disproof of spontaneous generation in the 19th
century, and was popularized earlier in this century by S.
Arrhenius. According to this view, a life spore was driven to
earth from somewhere else in the cosmos by electromagnetic
radiation pressure. The idea is sometimes called
radiopanspermia.
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Alternative Views on the Origin of Life:
Problems with Panspermia?
1. “Panspermia did not really answer the question of origins;
it merely pushed the problem to some other planet or place
in the cosmos.”
2. “Panspermia offered no way to protect life spores from the
lethal effects of intense radiation in space.”
3. “Panspermia offered no mechanism for safe entry through
the earth’s atmosphere.”
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Alternative Views on the Origin of Life:
A. New Natural Laws
B. Panspermia- A life spore was driven to earth from
somewhere else in the cosmos by electromagnetic
radiation pressure.
C. Directed Panspermia- Life spores were sent to earth
in some kind of rocket ship by extraterrestrial
intelligence (ETI.)
An Example of Directed Panspermia
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
“Also to be considered is an enterprising variation of
Panspermia called Directed Panspermia. Suggested
by F. C. and Leslie Orgel, this hypothesis purports
that life spores were sent to earth in some kind of
rocket ship by extraterrestrial intelligence (ETI), most
likely from some other galaxy. Speculations have
been numerous. Perhaps ETI purposely sent life
spores to earth to make it a “wilderness area or zoo,”
or perhaps a cosmic dump site. It is even possible life
spores were left here inadvertently “on some ancient
astronaut’s boot.”
An Example of
Directed
Panspermia
C, F. 1981. Life Itself: Its
Origin and Nature. Simon
and Schuster, N.Y., N.Y.
An Example of Directed Panspermia
C., F. 1981. Life Itself: Its Origin and Nature. Simon
and Schuster, N.Y., N.Y.
“In this book, I explore a variant of panspermia which
Leslie Orgel and I suggested a few years ago. To
avoid damage, the microorganisms are supposed to
have traveled in the head of an unmanned spaceship
sent to earth by a higher civilization which had
developed elsewhere some billions of years ago.
The spaceship was unmanned so that its range would
be as great as possible. Life started here when these
organisms were dropped into the primitive ocean and
began to multiply. We called our idea Directed
Panspermia and published it quietly in Icarus, a
space journal edited by Carl Sagan.”
Crick, Francis. 1981. Life
Itself: Its Origin and Nature.
Simon and Schuster, N.Y.,
N.Y.
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Alternative Views on the Origin of Life:
A. New Natural Laws
B. Panspermia- A life spore was driven to earth from
somewhere else in the cosmos by electromagnetic
radiation pressure.
C. Directed Panspermia- Life spores were sent to earth
in some kind of rocket ship by extraterrestrial
intelligence (ETI.)
D. Special Creation by a Creator within the CosmosAn intelligence created life and sent it to earth.
An Example of a Special Creation by a
Creator Within the Cosmos
From: Shapiro, R. 1986. Origins: A Skeptic’s Guide to the
Creation of Life on Earth. Bantam Books, N.Y., N.Y.
Hoyle and Wickramasinghe
“Hoyle was born in 1915 and spent
most of his career in various
faculty positions at Cambridge
University. This career was
marked by a number of
controversies concerning
university politics and
administrative matters.” http://www.panspermia.org/hoyle.jpg
An Example of a Special Creation by a
Creator Within the Cosmos
From: Shapiro, R. 1986. Origins: A Skeptic’s Guide to the
Creation of Life on Earth. Bantam Books, N.Y., N.Y.
“In the mid 1960’s, he resigned from the mathematics
faculty and threatened to emigrate to the United
States. He remained at Cambridge, however, as he
had been appointed head of the newly formed
Institute of Theoretical Astronomy. He left this post
and quit his Cambridge professorship in 1972, after
additional quarrels.”
An Example of a Special Creation by a
Creator Within the Cosmos
From: Shapiro, R. 1986. Origins: A Skeptic’s Guide to the
Creation of Life on Earth. Bantam Books, N.Y., N.Y.
“These controversies stand small when compared to the
many honors received by Hoyle, which include a
number of awards and medals. He has also been past
president of the Royal Astronomical Society, vicepresident of the Royal Society, and a foreign associate
of the U.S. National Academy of Science. He was
knighted in 1972.”
An Example of a Special Creation by a
Creator Within the Cosmos
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Hoyle and Wickramasinghe (H&W): “We come now to
what for us is a strong argument for the existence of
an overt plan of planetary invasion… we have so far
been unable to exterminate a single insect species.
Not even one among millions!”
An Example of a Special Creation by
a Creator Within the Cosmos
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
TBO: “And what do we learn from this curious fact?”
H&W: “The situation points clearly to one of two
possibilities. Either we are dealing with an overt plan
invented by and intelligence considerably higher than
our own,… or the insects have already experienced
selection pressure against intelligences of at least our
level in many other environments elsewhere in the
universe.”
An Example of a Special Creation by
a Creator Within the Cosmos
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
TBO: “The moment of truth finally arrives when we
learn the identity of the superintelligence. Hoyle and
Wickramasinghe ask, ‘Could the insects themselves
be the intelligence higher than our own’” If anyone
wonders why we are do long discovering their true
identity, Hoyle and Wickramasinghe suggests it is
because they do not wish to be known.”
H&W: “Perhaps concealment is an essential tactic.
Perhaps the intelligence is static because it
understands the dictum of sagacious lawyers: ‘When
your case is going well, say nothing.’”
An Example of a Special Creation by a
Creator Within the Cosmos
From: Shapiro, R. 1986. Origins: A Skeptic’s Guide to the
Creation of Life on Earth. Bantam Books, N.Y., N.Y.
Hoyle and Wickramasinghe: “While many are willing,
and some are anxious, to postulate an ultimately
surpassing intellect, God, few are happy with the
thought of intelligences intervening at levels between
ourselves and God. Yet surely there must be such
intelligences. It would be ridiculous to suppose
otherwise.”
An Example of a Special Creation by a
Creator Within the Cosmos
From: Shapiro, R. 1986. Origins: A Skeptic’s Guide to the
Creation of Life on Earth. Bantam Books, N.Y., N.Y.
Hoyle and Wickramasinghe: “Our own immediate
progenitor was ‘an extremely complex silicon chip.’
Such chips, so vital in modern computers, had the
computational power needed to design the first
bacteria. This was not done for altruistic purposes,
but rather that with the intent that the bacteria evolve
into beings capable of constructing computers,
thereby spreading silicon-chip life throughout the
universe.”
A Critique of Abiogenesis:
Thaxton, C. B., W. L. Bradley, and R. L. Olson.
Alternative Views on the Origin of Life:
A. New Natural Laws
B. Panspermia- A life spore was driven to earth from
somewhere else in the cosmos by electromagnetic
radiation pressure.
C. Directed Panspermia- Life spores were sent to earth
in some kind of rocket ship by extraterrestrial
intelligence (ETI.)
D. Special Creation by a Creator within the CosmosAn intelligence created life and sent it to earth.
E. Special Creation by a Creator beyond the Universe.
Romans 1:18-23 (NIV)
“The wrath of God is being revealed from heaven against all the
godlessness and wickedness of men who suppress the truth by
their wickedness, [19] since what may be known about God is
plain to them, because God has made it plain to them. [20] For
since the creation of the world God's invisible qualities--his
eternal power and divine nature--have been clearly seen, being
understood from what has been made, so that men are without
excuse.”
[21] “For although they knew God, they neither glorified him as
God nor gave thanks to him, but their thinking became futile and
their foolish hearts were darkened. [22] Although they claimed to
be wise, they became fools [23] and exchanged the glory of the
immortal God for images made to look like mortal man and birds
and animals and reptiles.”
[and insects and computer chips?]