Macroevolution

 notes
 
 
 
 

 Macro-1





"One of the most amazing aspects of evolution is how easy it is to account for major transformations through rather simple changes in developmental processes."

        D. Futuyma, Science on Trial, pg. 62.
 
 
 

"If I ask you, “What would I have to do to transform a primitive mammal into a bat or a whale?” the answer is “Nothing very drastic."

        D. Futuyma, Science on Trial, pg. 62.
 
 
 

"The fossil record had caused Darwin more grief than joy.  Nothing distressed him more than the Cambrian explosion, the coincident appearence of almost all complex organic designs."

         S. Gould, The Panda’s Thumb, pg. 238, 239.
 
 
 

"We've got to have some ancestors.  We'll pick those.  Why?  Because we know they have to be there, and these are the best candidates.  That's by and large the way it has worked.  I am not exaggerating."

        Gereth Nelson, Wall Street Journal Dec.9, 1986.
 
 
 

"If it could be shown that this fact [gaps between widely distinct groups] had always existed, the fact would be fatal to the doctrine of evolution."

        T. H. Huxley, Three Lectures on Evolution, 1882, quoted by Bird, Origin of Species revisited, vol 1, pg 59, 1993.
 
 
 

"The known fossil record fails to document a single example of phyletic (gradual) evolution accomplishing a major morphologic transition and hence offers no evidence that the gradualistic model can be valid."

        S. Stanley, Macroevolution, pg 39.
 
 
 

"Evolution cannot forever be going on somewhere else.  Yet that's how the fossil record has struck many a forlorn paleontologist looking to learn something about evolution."

        N. Eldredge,  Reinventing Darwin, 1995.
 
 
 

Regarding the fossil Archaeoraptor liaongensis, which was recently determined to be a fraud:
 

“This mix of advanced and primitive features is exactly what scientists would expect to find in dinosaurs experimenting with flight”
         Christopher Sloan, senior assistant editor, National Geographic, in “Feathers for T-REX”, Nov., 1999, pg 101,
 

 “This fossil is perhaps the best evidence since Archaeopteryx that birds did, in fact, evolve from certain types of carnivorous dinosaurs”
         Steven Czerkas, in “Feathers for T-REX”, National Geographic, Nov., 1999, pg 101,
 

...the missing link between dinosaurs and birds, the best evidence yet that today’s bobolink was yesterday’s primeval carnivore...
        Washington Post, Oct 16, 1999
 

...a true missing link between dinosaurs and birds...
         USA TODAY, Oct 15, 1999
 

...the first flying feathered dinosaur, a missing link between the lumbering lizards of years ago and the graceful birds of today.
         Albuquerque Journal, Oct 15, 1999
 


"What good is 5% of an eye?"

         S. J. Gould, quoted in The Blind Watchmaker, p. 81.
 
 

"Stasis is data."

        S. Gould and N. Eldridge, Nature  366, 18, 1993.
 
 
 
 
 
 
 
 
 

GOALS:
 

1.  What is macroevolution?
 

2.  What are the basic characteristics of the fossil record?  Does the fossil evidence support macroevolution?
 

3.  What are the competing theories of macroevolution?  What are the problems with each theory?


 
 
 
 
 
 

OUTLINE:
 

I.  Definitions
 

II.  Direct observations of macroevolution
 

III.  Fossil evidence

 a)  Reasonable expectations based on common ancestry

 b)  Actual data (characteristic features of fossil record)

 c)  General conclusions about the fossil record
 

IV.  Proposed mechanisms
 a)  Random genetic variation + natural selection

 b)  Punctuated equilibrium / Macromutations


 
 
 
 
 
 
 
 

I.  Possible Definitions

1)  Variation on the level of family, order, classes, and phyla

2)  Major structural transition

3)  Increase in complexity

4)  Increase in information


 
 

    1).  Textbook definition:

Microevolution = variation within species

Macroevolution = change between family, order, classes, and phyla

 
"A major question in evolutionary theory is whether microevolution (the gradual changes that take place within species) can account for macroevolution (the diversity among families, orders, classes, and phyla).  The process of speciation - the formation of new species-is considered of central importance in answering this question."
        Curtis and Barnes, Biology, pg 1029.


     2).  Major structural transition

 
"There is obviously an enormous difference between the evolution of a colour change in a moth's wing and the evolution of an organ like the human brain, and the differences among the fruit flies of Hawaii, for example, are utterly trivial compared with the differences between a mouse and an elephant or an octopus and a bee."
         M. Denton, Evolution:  A Theory in Crisis, pg 87.
 

Geneticists can study the gradual increase of favored genes within populations of fruit flies in laboratory bottles.....Orthodox neo-Darwinians extrapolate these even and continuous changes to the most profound structural transitions in the history of life.  ...  Macroevolution (major structural transition) is nothing more than microevolution (flies in bottles) extended.  ...  The shift of gene frequencies in local populations is an adequate model for all evolutionary processes - or so the current orthodoxy states.
         S. Gould, The Panda's Thumb, pg 187.


 
For example, changing a rodent-like mammal into a bat or a whale:
Darwinist
"If I ask you, "What would I have to do to transform a primitive mammal into a bat or a whale?" the answer is "Nothing very drastic."
         D. Futuyma, Science on Trial, pg 62.
Punctuationalist
"Let us suppose that we wish, hypothetically, to form a bat or a whale ... [by a] process of gradual transformation of established species.  If an average [species] lasts nearly a million years, or even longer, and we have at our disposal only ten million years, then we have only 10 or 15 species to allign end-to-end, to form a continuous lineage connecting our primitive little mammal with a bat or a whale.  This is clearly preposterous.  ...A chain of 10 or 15 of these might move us from one small rodent-like form to a slightly different one, perhaps representing a new genus, but not to a bat or a whale!"
         S. Stanley, The new evolutionary Timetable, (1981).

 

     3).  Increase in complexity
 

 
R. Dawkins, The Blind Watchmaker
 
"The problem is that of complex design",  preface

"Biology is the study of complicated things that give the appearance of having been designed for a purpose",  pg 1
 
 

Dawkins' definition of complexity:
 1.  many parts
 2.  unique arrangement (unlikely to have arisen by chance)
 3.  special function
that a living organism emerged by chance from a prebiotic soup is about as likely as that "a tornado sweeping through a junkyard might assemble a Boeing 747 from the materials therein."
        F. Hoyle
 

"What about our own bodies?  Each one of us is a machine, like an airliner only much more complicated.  Were we designed on a drawing board too, and were our parts assembled by a skilled engineer?  The answer is no."
         R. Dawkins, The Blind Watchmaker, pg 3.
 
 


     4).  Increase in information (best definition)
 

           (Grasse-Dobzhansky exchange)
 

 
Information does not equal order!(crystallization and other such examples are irrelevant)
 

"Our task is to find an algorithm, a natural law that leads to the origin of information.”
    Manfred Eigen, Steps towards Life:  A perspective on Evolution, 1992, pg 12.

"the problem of the origin of life is clearly basically equivalent to the problem of the origin of biological information."
    Bernd-Olaf Kuppers,  Information and the Origin of Life, 1990, 170-172

"the problems of speciation pale by comparison to the problems in accounting for the sources of functional information that code for the spectacular pageant of life on earth."
         Davis and Kenyon, Of Panda's and People, pg 85.
 
 

Examples of natural law producing order:
 

 1.  crystals (snowflakes, salt, etc)

 Macro-2




 2.  patterned motion in fluids

  tornados, water running out of a bathtub
  circular motion of gas in a box heated on one side


 3.  vesicles/micelles

 Macro-3




 4.  waves sorting pebbles on a beach
 

 5.  order out of chaos (computer programs)
 
 

Natural law produces simple repetitive order, like a book reading  "ABABABABABABAB" on all of its pages.  Contrast this with the information content of a novel.  The information in a book does not originate from the properties of paper and ink, but originates in the mind of an intelligent author.
 
 

contrast the sorting of pebbles on a beach with the following:
 
 

  Macro-4


 
 

II.  Direct observations of macroevolution
 

None!   Observed change is limited to microevolution!

"Fruit flies refuse to become anything but fruit flies under any circumstances yet devised."
         Francis Hitching, The Neck of the Giraffe: Where Darwin Went Wrong, pp 56-57.
 

Evidences of macroevolution listed in the biology text by Curtis and Barnes:

1.  The number of species
2.  Biogeography
3.  The fossil record
4.  Homology
5.  The imperfection of adaptation
If laboratory science cannot establish a mechanism, and if fossil studies cannot find the common ancestors and transitional links, then Darwinism fails as an empirical theory.
         P. Johnson, Darwin on Trial, pg 66.

 

 III.  Fossil evidence
 

    a)  Reasonable expectations based on common ancestry
 

Quotes by Darwin in The Origin of Species:
"why, if species have descended from other species by insensibly fine gradations, do we not everywhere see innumerable transitional forms?

"the number of intermediate and transitional links between all living and extinct species must have been inconceivably great"

"[Since] innumerable transitional forms must have existed, why do we not find them imbedded in countless numbers in the crust of the earth?  Why is not every geological formation and every stratum full of such intermediate links?  Geology assuredly does not reveal any such finely graduated organic chain; and this is perhaps is the most obvious and gravest objection which can be urged against my theory."
     C. Darwin quoted in The Origin of Species By Means of Natural Selection, 1974, pg 202, 292.


 
"we must suppose the existence of innumerable collateral branches leading to many unknown types.  This was clearly Darwin's view and it implies that the total number of species which must have existed between the discontinuities must have been much greater than the number of species on the shortest direct evolutionary pathway.
         M. Denton, Evolution: A Theory in Crisis  pg 174.
 
 

The cone of increasing diversity
predicted by Darwinian macroevolution

 Macro-5


 
"Darwin's theory predicted not merely that fossil transitionals would be found; it implied that a truly complete fossil record would be mostly transitionals"
         P. Johnson, Darwin on Trial, pg 48
"To demonstrate that the great divisions of nature were really bridged by transitional forms in the past, it is not sufficient to find in the fossil record one or two types of organisms of doubtful affinity which might be placed on skeletal grounds in a relatively intermediate position between other groups."
         M. Denton, Evolution: A Theory in Crisis  pg 177.
 

"if the fossil record is to provide any grounds for believing that the great divisions of nature are not the unbridgeable discontinuities postulated by Cuvier, it is not sufficient that two groups merely approach one another closely in terms of their skeletal morphology.  The very least required would be an unambiguous continuum of transitional species exhibiting a perfect gradation of skeletal form leading unarguably from one type to another."
         M. Denton, Evolution: A Theory in Crisis  pg 182.
 
 
 

     How complete is the current fossil record?
 
In Darwin's day:
"The geological record is extremely imperfect and this fact will to a large extent explain why we do not find interminable varieties, connecting together all the extinct and existing forms of life by the finest graduated steps.  He who rejects these views on the nature of the geological record, will rightly reject my whole theory."
         C. Darwin, quoted by S. Gould in "Evolution's Erratic Pace", Natural History, vol 86, May 1977.


Today:

"So vast has been the expansion of paleontological activity over the past one hundred years that probably 99.9% of all paleontolotical work has been carried out since 1860.
         M. Denton, Evolution: A Theory in Crisis  pg 160.
 

"With an estimated 250 million, or 1/4 billion cataloged fossils of some 250,000 fossil species, the problem does certainly not appear to be an imperfect record."
         The Creation Hypothesis, pg 278.
 

"Well, we are now about 120 years after Darwin and the knowledge of the fossil records has been greatly expanded.  We now have a quarter of a million fossil species but the situation hasn't changed much.  The record of evolution is still surprisingly jerky and, ironically, we have even fewer examples of evolutionary transition than we had in Darwin's time."
         D. Raup, "Conflicts Between Darsin and Paleontology", Field Museum of Natural History Bulletin, Jan. 1979, p 22, 25.
 

 "Paleontologists just were not seeing the expected changes in their fossils as they pursued them up through the rock record.   That individual kinds of fossils remain recognizably the same throughout the length of their occurrence in the fossil record had been known to paleontologists long before Darwin published his Origin.  Darwin himself, .., prophesied that future generations of paleontologists would fill in these gaps by diligent search...  One hundred and twenty years of paleontological research later, it has become abundantly clear that the fossil record will not confirm this part of Darwin's prediction.  Nor is the problem a miserly fossil record.  The fossil record simply shows that this prediction is wrong.
        N. Eldredge and I. Tattersall, The Myths of Human Evolution, 1982, pg 45-46.
 
 
 

    b)  Actual data (characteristic features of fossil record)
 
 1.  Layers with succession of first appearances

 2.  Abrupt appearance

 3.  Stasis

 4.  Abrupt disappearance

 5.  Gaps, (increase in intensity as the taxonomic hierearchy is ascended)


 
 
 

        1.  Layers with succession of first appearances

 
"A third line of evidence in support of macroevolution is provided by the fossil record, which reveals a succession of living forms, with simpler forms generally preceding more complex forms."
        Curtis and Barnes, "Biology ", pg 966.
 
 

"The remains of extinct creatures are probably the most convincing proof of the reality of evolutionary descent of living creatures, but they cast doubt on the theory that random variation and natural selection suffice to account for it."
        R.  Wesson, "Beyond Natural Selection", pg 38


 

 Macro-6          Macro-7


        2.  Abrupt appearance
 
The history of most fossil species includes two features particularly inconsistent with gradualism:

1.  Stasis.  Most species exhibit no directional change during their tenure on earth.  They appear in the fossil recored looking pretty much the same as when they disappear; morphological change is usually limited and directionless.

2.  Sudden appearance.  In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and "fully formed".

         S. Gould, "Evolution's Erratic Pace", Nat. History, 1977.
 

 
"As is now well known, most fossil species appear instantaneously in the fossil record."
         T. Kemp,  "A Fresh Look at the Fossil Record", New Scientist, 108, pg 66, 1985.
 

"Most families, orders, classes, and phyla appear rather suddenly in the fossil record, often without anatomically intermediate forms smoothly interlinking evolutionarily derived descendant taxa with their presumed ancestors.
         N. Eldredge, Macro-Evolutionary Dynamics:  Species, Niches, and Adaptive Peaks, 1989,
         pg 22.
 

"It remains true, as every paleontologist knows, that most new species, genera, and families, and that nearly all categories above the level of families, appear in the record suddenly, and are not led up to by gradual, completely continuous transitional sequences."
        G. G. Simpson, The Major Features of Evolution, pg 360.

 

Most dramatic example:  The Cambrian Explosion - abrupt appearance of all phyla

(phyla - basic body plans, greatest differences within the animal kingdom)
 "The gaps which separate species:  dog/cat, rat/mouse etc are utterly trivial compared with, say, that between a primitive terrestrial mammal and a whale or a primitive terrestrial reptile and an Ichthyosaur; and even these relatively major discontinuities are trivial alongside those which divide major phyla such as molluscs and arthropods."
         M. Denton,  Evolution:  A Theory in Crisis,  pg 193.
"The fossil record had caused Darwin more grief than joy.  Nothing distressed him more than the Cambrian explosion, the coincident appearance of almost all complex organic designs ... "
        S. Gould, The Panda's Thumb, pg 238, 239.
 

"Consequently, if my theory be true, it is indisputable that before the lowest Silurian stratum was deposited, long periods elapsed, as long as, or probably longer than the whole interval from the Silurian age to the present day; and during these vast, yet quite unknown periods of time, the world swarmed with living creatures.  To the question why we do not find records of these vast primordial periods, I can give no satisfactory answer."
        Charles Darwin, On the Origin of Species, 1st edition, pg 307.
 

Darwinian macroevolution predicts a cone of increasing diversity, with an increase in the diversity of body plans (or phyla) over time.  This prediction has been shown to be false.


 

Macro-9            Macro-10



 
 
 

Below are some of the fossilized creatures discovered in the Burgess Shale (from "Wonderful Life" by S. Gould).  The abrupt appearance in the Cambrian of organisms with widely differing body plans, without any record of preceding organisms showing a gradual development from a common ancestor, is perhaps the most important enigma of the fossil record for naturalists.

 


 

 Macro-11        Macro-12         Macro-13         Macro-14        Macro-15        Macro-16


 
 

          3.  Stasis
 

The history of most fossil species includes two features particularly inconsistent with gradualism:

1.  Stasis.  Most species exhibit no directional change during their tenure on earth.  They appear in the fossil record looking pretty much the same as when they disappear; morphological change is usually limited and directionless.

2.  Sudden appearance.  In any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and "fully formed".
        S. Gould, "Evolution's Erratic Pace", Nat. History, 1977.
 
 

"The gaps in the fossil record are real, however.  The absence of any important branching is quite phenomenal.  Species are usually static, or nearly so, for long periods; species seldom and genera never show evolution into new species but replacement of one by another, and change is more or less abrupt."
        R. Wesson, Beyond Natural Selection, 1991, pg 45.
 

 "Paleontologists just were not seeing the expected changes in their fossils as they pursued them up through the rock record.   That individual kinds of fossils remain recognizably the same throughout the length of their occurrence in the fossil record had been known to paleontologists long before Darwin published his Origin.  Darwin himself, .., prophesied that future generations of paleontologists would fill in these gaps by diligent search...  One hundred and twenty years of paleontological research later, it has become abundantly clear that the fossil record will not confirm this part of Darwin's prediction.  Nor is the problem a miserly fossil record.  The fossil record simply shows that this prediction is wrong.

The observation that species are amazingly conservative and static entities throughout long periods of time has all the qualities of the emperor's new clothes: everyone knew it but preferred to ignore it.  Paleontologists, faced with a recalcitrant record obstinately refusing to yield Darwin's predicted pattern, simply looked the other way."
        N. Eldredge and I. Tattersall, The Myths of Human Evolution, 1982, pg 45-46.
 

 "Well represented species are usually stable throughout their temporal range, or alter so little and in such superficial ways (usually in size alone), that an extrapolation of observed change into longer periods of geological time could not possibly yield the extensive modifications that mark general pathways of evolution in larger groups.  Most of the time, when the evidence is best, nothing much happen to most species."
        S. J. Gould, "Ten Thousand Acts of Kindness", Natural History,  Dec. 1988, p 14.
 

"Stasis, or nonchange, of most fossil species during their lengthy geological lifespans was tacitly acknowledged by all paleontologists, but almost never studied explicitly because prevailing theory treated stasis as uninteresting nonevidence for evolution.  The overwhelming prevalence of stasis became an embarrassing feature of the fossil record, best left ignored as a manifestation of nothing (that is, nonevolution)."
        S. J. Gould, "Cordelia's dilema, Natural History, Feb. 1993, p 15.
 
 

         4.  Abrupt disappearance
 
"Darwin recognized that his theory required a pattern of extinction even more gradual than the pattern of evolutionary emergence.

Continual, gradual extinctions are a necessary consequence of the assumption that ancestor species are constantly being supplanted by better adapted descendants."
        P. Johnson, Darwin on Trial, pg 49.
 

"There is reason to believe that the complete extinction of the species of a group is generally a slower process than their production:  if the appearance and disappearance of a group of species be represented ... by a vertical line of varying thickness, the line is found to taper more gradually at its upper end, which marks the progress of extermination, than in its lower end, which marks the first appearance and increase in numbers of the species.  In some cases, however, the extermination of whole groups of beings, as of ammonites towards the close of the secondary period, has been wonderfully sudden.
         C. Darwin, Origin of Species.
 

"The gaps in the fossil record are real, however.  The absence of any important branching is quite phenomenal.  Species are usually static, or nearly so, for long periods; species seldom and genera never show evolution into new species but replacement of one by another, and change is more or less abrupt."
         R. Wesson, "Beyond Natural Selection", 1991, pg 45.


 
 
 
Abrupt disappearance of large numbers of species from the geological column:
 
End of Cretaceous - dinosaurs

End of Permian  63% of terrestrial families,  49% marine families


 
 

        5.  Gaps (lack of transitional fossils)
 

A.  Statements affirming the existence of gaps

B.  Examples

C.  Patterns

 1)  Gaps increase in intensity as the taxonomic hierearchy is ascended

 2)  Disparity precedes diversity


D.  Supposed transitional forms

 

 
A.  Statements affirming the existence of gaps
 
"If it could be shown that this fact [gaps between widely distinct groups] had always existed, the fact would be fatal to the doctrine of evolution."
         T. H. Huxley, Three Lectures on Evolution, 1882, quoted by Bird, Origin of Species
         revisited, vol 1, pg 59, 1993.
 

"The virtual complete absence of intermediate and ancestral forms from the fossil record is today recognized widely by many leading paleontologists as one of its most striking characteristics..."
         M. Denton, Evolution:  A Theory in Crisis, pg 165
 

The greatest riddle of evolution has been the following puzzle:  while Darwin argued that new species emerge through a slow, gradual accumulation of tiny mutations, the fossil record reveals a very different scenario-the sudden emergence of whole new species, with no apparent immediate ancestors.
    Inside cover of Sudden Origins, by J. H. Schwartz, 1999.
 

"The gaps in the fossil record are real, however.  The absence of a record of any important branching is quite phenomenal.  Species are usually static, or nearly so, for long periods, species seldom and genera never show evolution into a new species or genera but replacement of one by another, and change is more or less abrupt. ... The origin of no innovation of large evolutionary significance is known. ... Large evolutionary innovations are not well understood.  None has ever been observed, and we have no idea whether any may be in progress.  There is no good fossil record of any."
         R. Wesson, Beyond Natural Selection, pg 45, 1991.
 

"What one actually found was nothing but discontinuities.  All species are separated from each other by bridgeless gaps; intermediates between species are not observed.  The problem was even more serious at the level of the higher categories."
        E. Mayr, The Growth of Biological Thought:  Diversity, Evolution, and Inheritance, pg 524.
 

"There are all sorts of gaps; absence of gradationally intermediate transitional forms between species, but also between larger groups - between, say, families of carnivores, or the orders of mammals.  In fact, the higher up the Linnaean hierarchy you look, the fewer the transitional forms there seem to be."
        N. Eldredge The Monkey Business:  A Scientist Looks at Creationism 1982.
 

"We are faced more with a great leap of faith - that gradual, progressive adaptive change underlies the general pattern of evolutionary change we see in the rocks - than any hard evidence. ... The record jumps, and all the evidence shows that the record is real:  the gaps we see reflect real events in life's history - not the artifact of a poor fossil record. ... The fossil record flatly fails to substantiate this expectation of finely graded change."
         N. Eldredge, I. Tattersall, The Myths of Human Evolution, 1982, pg 59.
 

"The known fossil record fails to document a single example of phyletic (gradual) evolution accomplishing a major morphologic transition and hence offers no evidence that the gradualistic model can be valid."
         S. Stanley, Macroevolution, pg 39.
 

"  the fossil record tells us almost nothing about the evolutionary origin of phyla and classes.  Intermediate forms are non-existent, undiscovered, or not recognized."
         R. Barnes Paleobiology,  6, 365, 1980.
 

"The extreme rarity of transitional forms in the fossil record persists as the trade secret of paleontology.  The evolutionary trees that adorn our textbooks have data only at the tips and nodes of their branches:  the rest is inference, however, reasonable, not the evidence of the fossils.  Yet Darwin was so wedded to gradualism that he wagered his entire theory on a denial of the literal record.

"The geological record is extremely imperfect and this fact will to a large extent explain why we do not find interminable varieties, connecting together all the extinct and existing forms of life by the finest graduated steps.  He who rejects these views on the nature of the geological record, will rightly reject my whole theory."

Darwin's argument still persists as the favored escape of most paleontologists from the embarrassment of a record that seems to show so little of evolution.

Paleontologists have paid an exorbitant price for Darwin's argument.  We fancy ourselves as the only true students of life's history, yet to preserve our favored account of evolution by natural selection we view our data as so bad that we never see the very process we profess to study."
         S. J. Gould, "Evolution's Erratic Pace" Natural History , 86, 1977.
 

"The fossil record  with its abrupt transitions offers no support for gradual change. ... All paleontologists know that the fossil record contains precious little in the way of intermediate forms; transitions between major groups are characteristically abrupt."
         S. J. Gould, "The Return of Hopeful Monsters" Natural History , pp 22, 24, 1977.
 

"Rather than supporting evolution, the breaks in the known fossil record support the creation of major groups with the possibility of some limited variation within each group."
         D. Ager, "The Nature of the Fossil Record", Proceedings of the Geological Association 87 (1976): 133.
 

"But I still think that, to the unprejudiced, the fossil record of plants is in favor of special creation. ... Can you imagine how an orchid, a duck weed, and a palm have come from the same ancestry, and have we any evidence for this assumption?  The evolutionist must be prepared with an answer, but I think that most would break down before an inquisition."
         E. J. Corner, "Evolution" in Contemporary Botanical Thought, ed Anna M Macleod and L. S. Cobley (Chicago: Quadrangle Books, 1961), pg 97.
 

"I fully agree with your comments on the lack of direct illustration of evolutionary transitions in my book.  If I knew of any, fossil or living, I would certainly have included them. ... I will lay it on the line - there is not one such fossil for which one could make a watertight argument."
         Collin Patterson, in a letter to L. Sunderland in 1979, Quoted in Bird, Origin of Species Revisited, 1:59.
 

" We do not actually know the phylogenetic history of any group of plants and animals, since it lies in the indecipherable past."
         E. Core et al., General Biology, 4th ed. (New York, 1961) p 299.
 

"Unfortunately, the origins of most higher categories are shrouded in mystery; commonly new higher categories appear abruptly in the fossil record without evidence of transitional forms."
         D. Raup and S. Stanley, Principles of Paleontology (San Fran. 1978), p 372.
 

"Whatever ideas authorities may have on the subject, the lungfish, like every other major group of fish that I know, have their origins firmly based on nothing."
         E. White, "Presidential Address:  A Little on Lungfishes," Proceedings of the Linnean Society 177 (1966), pg 8.
 

"Well, we are now about 120 years after Darwin and the knowledge of the fossil records has been greatly expanded.  We now have a quarter of a million fossil species but the situation hasn't changed much.  The record of evolution is still surprisingly jerky and, ironically, we have even fewer examples of evolutionary transition than we had in Darwin's time."
         D. Raup, "Conflicts Between Darsin and Paleontology", Field Museum of Natural History Bulletin, Jan. 1979, p 22, 25.
 

"A large number of well-trained scientists outside of evolutionary biology and paleontology have unfortunately gotten the idea that the fossil record is far more Darwinian than it is.  This probably comes from the oversimplification inevitable in secondary sources:  low-level textbooks, semipopular articles, and so on.  Also, there is probably some wishful thinking involved.  In the years after Darwin, his advocates hoped to find predictable progressions.  In general these have not been found yet the optimism has died hard, and some pure fantasy has crept into the textbooks."  Science,  July 17. 1981, pg 289.
 
 

Two examples:

Ex. 1.   "Nowhere in the geological record ... did Darwin find exactly what he was seeking:  evidence of a gradual transition between one species and another.  Thus, as Darwin reiterates in The Origin Of Species, the fossil record provided little evidence for him of how evolution came about.  For Darwin's contemporaries, however, as for modern observers, the fossil record provided the overwhelming evidence that evolution had indeed occurred.
     In the twentieth century, a steady stream of new discoveries has enormously increased our knowledge of the fossil record......  In the case of many groups of organisms-vascular plants and vertebrates, for example, as we saw in chapters 24 and 28- fossils have been found that exhibit a graded series of changes in anatomical characteristics, linking older forms with the modern forms and revealing pathways of divergence from common ancestors.
         Curtis and Barnes, Biology, pg 967,968.
 

Ex. 2.   Can more extensive evolutionary change, macroevolution, be explained as an outcome of these microevolutionary shifts?  Did birds really arise from reptiles by an accumulation of gene substitutions of the kind illustrated by the rasberry eye-color gene?
 The answer is that it is entirely plausible, and no one has come up with a better explanation. ... The fossil record suggests that macroevolution is indeed gradual, paced at a rate that leads to the conclusion that it is based on hundreds or thousands of gene substitutions no different in kind from the ones examined in our case histories.
        From a textbook described by S. Gould as "the most sophisticated of modern American textbooks for introductory biology", quoted by P. Johnson, in Darwin on Trial, pg 50.pg 967,968.

 
B.  Examples
 
 

 Macro-17                Macro-18                Macro-19               Macro-20               Macro-21


 
C.  Patterns:
1)  Gaps increase in intensity as the taxonomic hierearchy is ascended
 
What one actually found was nothing but discontinuities.  All species are separated from each other by bridgeless gaps; intermediates between species are not observed.  The problem was even more serious at the level of the higher categories.
         E. Mayr, The Growth of Biological Thought:  Diversity, Evolution, and Inheritance, pg 524.

There are all sorts of gaps; absence of gradationally intermediate transitional forms between species, but also between larger groups - between, say, families of carnivores, or the orders of mammals.  In fact, the higher up the Linnaean hierarchy you look, the fewer the transitional forms there seem to be.
         N. Eldredge The Monkey Business:  A Scientist Looks at Creationism  1982.
 
 

2)  Disparity precedes diversity

"We may acknowledge a central and surprising fact of life's history - marked decrease in disparity followed by an outstanding increase in diversity within the few surviving designs."
         S. J. Gould, 1989.
 
 

   Macro-22              Macro-23


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