origins - microevolution. dna review building blocks of evolutionary theory – population growth

Origins - Microevolution

DNA Review

BuildingBlocks of Evolutionary Theory – Population Growth

BuildingBlocks of Evolutionary Theory – Variation• Morphological• Physiological• Behaviorally

Potato varieties.

Credit: © David Cavagnaro

Blood Stars (Henricia leviuscula) showing genetic variation.

Credit: © Stan Elems

Land snails, genetic variation, Hawaii.

Credit: © Dr. Donald Fawcett

Sources of Genetic Variation Mutation Crossing over at meiosis I Independent assortment

Fertilization

Change in chromosome number or

structure

BuildingBlocks of Evolutionary Theory – The Gene Pool

• The sum of all of the alleles for all the genes for all the individuals in the population

BuildingBlocks of Evolutionary Theory – Natural Selection

Range of values at time 3

Nu

mb

er o

f in

div

idu

als


Nu

mb

er o

f in

div

idu

als

Directional selection


Nu

mb

er o

f in

div

idu

als

Stepped Art

Fig. 16-14, p.249


Nu

mb

er o

f in

div

idu

als


Nu

mb

er o

f in

div

idu

als

Stabilizing Selection


Nu

mb

er o

f in

div

idu

als

Stepped Art

Fig. 16-16, p.250


Nu

mb

er o

f in

div

idu

als

Disruptive Selection


Nu

mb

er o

f in

div

idu

als


Nu

mb

er o

f in

div

idu

als

Stepped Art

Fig. 16-16, p.250

Fig. 16-17, p.25113,730 human births

Fig. 16-15a, p.249

Fig. 16-15b, p.249Rock pocket mice – on dark lava and “regular” desert.

Black-bellied seedcracker of Cameroon showing two beak sizes showing selection for two sedge seed sizes.

lower bill 12 mm wide lower bill 15 mm wide

Evolution

RL

GV

NST

eneticariation

eproductionand

aturalelectionime

Hardy-Weinberg EquilibriumLet “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 = 1.0In a diploid population, individuals are

represented by:(p + q)2 = 1.0

p2 + 2pq + q2 = 1.0

animation

Click to view animation.

Hardy-Weinberg EquilibriumN=20Red = 15/20 = A_ = p2 + 2pqWhite = 5/20 = aa = q2

q2 = 5/20 = 0.25q = 0.50

p + q = 1.00p = 1.00 – q = 1.00 – 0.50 = 0.50

MutationNo mutation

“Violation”: Agents of Evolutionary (Gene Pool) change

Condition required for Hardy-Weinberg

Equilibrium

Hardy-Weinberg EquilibriumMutation:N=20Red = 15/20 = A_ = p2 + 2pqWhite = 4/20 = aa = q2

q2 = 4/20 = 0.20q = 0.45

Genetic drift (including population bottleneck and the founder effect

Large population

MutationNo mutation



Equilibrium

Hardy-Weinberg EquilibriumPopulation Bottleneck:N=3Red = 3/3 = A_ = p2 + 2pqWhite = 0/3 = aa = q2

q2 = 0/3 = 0.00q = 0.0

AA in five populations

allele A lostfrom fourpopulations

allele A neitherlost norfixed

1.0

0.5

01 505 10 15 20 25 30 35 40 45

Generation (25 stoneflies at the start of each)

1.0

0.5

01 505 10 15 20 25 30 35 40 45

Generation (500 stoneflies at the start of each) Fig. 16-22, p.254

animation

Click to view animation.

YearEstimated American

bison population size

Before 1492 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.

Gene flowNo gene flow

(immigration/emigration)


Large population

MutationNo mutation



Equilibrium

Hardy-Weinberg EquilibriumGene Flow:IF new seeds enter the population…N=23Red = 15/23 = A_ = p2 + 2pqWhite = 8/23 = aa = q2

q2 = 8/23 = 0.35q = 0.59

Fig. 16-24a, p.255Gene flow

Fig. 16-24, p.255

Nonrandom matingRandom mating




Large population

MutationNo mutation



Equilibrium

Hardy-Weinberg EquilibriumNonrandom mating:IF red only fertilizes red…Red = 15/20 = A_ = p2 + 2pqp2 = 0.502 = 0.25(20) = 5AA2pq = 2(0.50)(0.50)

= 0.50(20) = 10AaA = p = 20/30 = 0.67a = q = 10/30 = 0.33q2 = (0.33)2 = 0.11(20) = 2

Natural selectionNo natural selection - Gene doesn’t affect survival or reproduction

Nonrandom matingRandom mating




Large population

MutationNo mutation



Equilibrium

Hardy-Weinberg EquilibriumNatural selection:IF insects only see red…Red = 15/20 = A_ = p2 + 2pqp2 = 0.502 = 0.25(20) = 5AA2pq = 2(0.50)(0.50)

= 0.50(20) = 10AaA = p = 20/30 = 0.67a = q = 10/30 = 0.33q2 = (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). Ihttp://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 well-camouflaged 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.”


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).


Origins – Speciation or Macroevolution

Fig. 16-5a, p.40

Fig. 16-5b, p.240

EQUATOR

GalapagosIslands

route of Beagle

Fig. 16-5c, p.241

Fig. 16-5d, p.241

Darwin

Wolf

Pinta

GenovesaMarchena

SantiagoBartolome

EQUATOR

Seymour

Blatra

Santa Cruz

RabidaPinzonFernandina

Tortuga

Isabela

Santa FeSan Cristobal

Espanola

Floreana

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 SpeciesChapter 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 SpeciesThe 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 SpeciesThe 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 SpeciesChapter 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 SpeciesThese 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 SpeciesChapter 3 - Struggle for ExistenceHow 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 SpeciesNothing 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 SpeciesIt 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.

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)

Thomas Malthus1766 - 1834

http://en.wikipedia.org/wiki/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.

Thomas Malthus

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 SpeciesChapter 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 SpeciesNatural 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 SpeciesAccording 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.

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

Ernst Mayr1904-2005

Prezygotic Isolating Mechanisms Ecogeographic isolation Habitat/Ecological isolation Temporal variation Behavioral variation (animals only!) Mechanical Sperm/female or Pollen/stigma

incompatibility Gamete isolation

Fig. 17-17c, p.272Temporal isolation in 17 and 13 year cicada species

Fig. 17-17b, p.272Reproductive behaviors

Fig. 17-17a, p.272

Mechanical isolation in the pollinators of orchids

Postzygotic Isolating Mechanisms Developmental isolation Hybrid inviablilty Hybrid sterility

Zebroids, hydrids between horse and zebra.

Credit: © Michele Burgess/Visuals Unlimited

Speciation Allopatric Sympatric

Large Cactus FinchGeospiza conirostris

Fig. 16-7b, p.243

Common Cactus-FinchGeospiza scandens

Galapagos Medium Ground Finch (Geospiza fortis), Isabela Island, Galapagos.

Credit: © Gerald and Buff Corsi

228690

Medium Ground FinchGeospiza fortis

Warbler FinchCerthidea olivacea

Woodpecker FinchCamarhynchus pallidus

Origins –Spontaneous Generation and Abiogenesis

Spontaneous GenerationAccording 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 - 1703http://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

Francesco Redi1626 - 1697http://en.wikipedia.org/wiki/Francesco_Redi

Meat in a closed container –Nothing happens

Meat in a screened in container –Nothing happens

Meat in an open container –Maggots happen!

Spontaneous Generation

Louis Pasteur1822 - 1895http://en.wikipedia.org/wiki/Louis_Pasteur

Abiogenesis

RawMaterialsAndEnergy

Monomers monosaccharides fatty acids amino acids purines/ pyrimidines

Polymers carbohydrates lipids proteins nucleotides and nucleic acids

Protocells Cells

Abiogenesis – Different Conditions

A. I. Oparin 1894 - 1980http://en.wikipedia.org/wiki/Oparin

Matter: methane, ammonia, hydrogen, and water; carbon monoxide, carbon dioxide, nitrogen

Energy: heat, electricity, uv radiation

Abiogenesis – Testing Oparin

Stanley Miller1930 -

to vacuum pump

CH4

NH3

H2OH2

gases

electrodes

spark discharge

water out

condenser

water in

water droplets

water containingorganic compounds

liquid water in trapboiling water

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 N-Propylglycine 2

Norvaline 61 N- Isopropylglycine 2

Isovaline 5 N -Methylalanine 15

Leucine 11.3 N-Ethylalanine < 0.2

Isoleucine 4.8 b-Alanine 18.8

Alloisoleucine 5.1 b-Amino-n-butyric acid 0.3

Norleucine 6.0 b-Amino-isobutyric acid 0.3

tert-Leucine < 0.02 g-Aminobutyric acid 2.4

Proline 1.5 N-Methyl-b-alanine 5

Aspartic acid 34 N-Ethyl-b-alanine 2

Glutamic acid 7.7 Pipecolic acid 0.05

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.)

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 Percent Yield*

Aspartic acid 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-Smith1931 -

Fig. 18-4a, p.290Clay templates in tidal flats

Fig. 18-4b, p.290Iron sulfide-rich rocks at hydrothermal vents

Abiogenesis– Proteinoid Microspheres

Sidney W. Fox1912 - 1998

p.286b

Fig. 18-5b, p.291

RNA-coated clay (red) surrounded by a membrane of fatty acids and alcohols (green)

Abiogenesis

RawMaterialsAndEnergy

Monomers monosaccharides fatty acids amino acids purines/ pyrimidines

Polymers carbohydrates lipids proteins nucleotides and nucleic acids

Protocells Cells

OparinMiller FoxCairnes-Smith

Fig. 18-6a, p.292

A strand of what may be a walled prokaryotic cells dating back 3.5 billion years.

DNA

infolding of plasma membraneFig. 18-8a, p.294

Current Nitrobacter

Fig. 18-8b, p.294

Theoretical Model of formation of nuclear membrane and endoplasmic reticulum

Fig. 18-9b, p.295Cyanophora paradoxa

nucleus

mitochondrion

photosynthetic organelle thatresembles a cyanobacterium

Fig. 18-9a, p.295

Cyanophora paradoxa contains mitochondria that resemble aerobic bacteria. It’s photosynthetic structures resemble cyanobacteria.

Endosymbiosis?

hydrogen-rich anaerobic atmosphere atmospheric oxygen, 10%

archaean lineage

dancestors ofeukaryotes

hendomembrane

system and nucleus

b

origin ofprokaryotes

cyclic pathwayof photosynthesis

e

noncyclic pathwayof photosynthesisf

g aerobic respiration

3.8 billion years ago



a

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 LawsB. 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 PanspermiaThaxton, 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 PanspermiaC., 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.




D. Special Creation by a Creator within the Cosmos- An intelligence created life and sent it to earth.

An Example of a Special Creation by a Creator Within the CosmosFrom: 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 CosmosFrom: 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 CosmosFrom: 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, vice-president 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 CosmosFrom: 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 CosmosFrom: 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.”




D. Special Creation by a Creator within the Cosmos- An 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?]

origins - microevolution. dna review building blocks of evolutionary theory – population growth

Documents

bottleneck slide

wide slide

gene flow slide

structure slide

dna review slide

david cavagnaro slide

stan elems slide

donald fawcett slide