| The
Fossil Record -- The History of Life on Earth
The
fossil record which gives the history of life on earth
is quite rightly considered to be a primary source of
evidence for determining how life came into existence.
It is, however, an extremely complicated record to interpret.
The number of fossils is enormous, many are fragmentary,
and even in fairly complete fossils, softer tissues
may be lacking. The record could have gaps resulting
from periods of time when sedimentary layers and their
fossil content were not formed. Also the sedimentary
layers are by no means uniform across the globe. As
a result it is not a trivial matter to match layers
of the same age at different locations.
Because
of the obtuseness of the fossil record, people who study
it have vastly different opinions on what it is saying
about the mechanisms that caused all of life's organisms.
In general the more obtuse the evidence, the more likely
it is that an investigator's preconceived ideas will
influence his interpretation of the evidence. Thus there
are scientists who are convinced that the fossil record
shows the biological evolution of all forms of life
from simpler to more complex. Others are just as convinced
that the fossil record does not support biological evolution
and that a scientific explanation for the existence
of life does not exist.
Much
of what follows has been taken from Robert L. Carroll's
book, Vertebrate Paleontology and Evolution
published in 1988. This is a compilation of results
from all areas of vertebrate paleontology. It contains
many hundreds of citations. Compilations of this magnitude
seem to appear about every twenty years. Alfred Romer
authored his three editions of Vertebrate Paleontology
in 1933, 1945 and 1966.
Evidence
From the Fossil Record
Consider
what Darwin expected to find in the rocks and sedimentary
layers of the earth; all forms of life connected by
"infinitely numerous transitional links" and
"every stratum full of such intermediate links"1.
One hundred and fifty years later the expectations of
Darwin have not come close to being realized. Consider
the following facts about the fossil record:
1)
Phylum is the broadest classification of animals, there
being about 35 phyla. Each animal phylum has a unique
body plan. Some animal phyla are: the vertebrates which
include reptiles, mammals, fish and birds; arthropods
which include spiders, insects and crustaceans; annelids
which include earthworms and leeches; mollusks which
include clams, oysters and scallops; echinoderms which
include starfish, sea urchins and sea cucumbers; and
coelenterates (cnidarians) which include jellyfish,
sea anemones and corals. Every fossil found to date
belongs to one of the phyla. That means that transitional
forms between the phyla have never been found.
A University of Cambridge paleontologist, S. Conway
Morris writes: "A few principles are widely, but
not universally, accepted, but no current phylogeny
for the roughly 35 metazoan phyla exists...The morphological
gaps that, by definition, separate phyla, remain inviolate.
We remain uninformed both about the now-extinct intermediates
and the evolutionary processes that would have been
responsible for the diversification of early multicellular
animals into what we now perceive as distinct phyla,
each with its own body plan...." S. C. Morris,
Nature 361:219-225 (1993).
2) Complex, multi-celled animals of all the invertebrate
phyla appear suddenly and simultaneously in the Cambrian
era. Suddenly means that simpler animals that should
be the evolutionary ancestors of the Cambrian invertebrates
have not been found. "In Cambrian rocks are found
fossils of clams, snails, trilobites, sponges, brachiopods,
worms, jellyfish, sea urchins, sea cucumbers, swimming
crustaceans, sea lilies and other complex invertebrates."2
The
evolutionist, Douglas Futuyma, writes: "It is considered
likely that all the animal phyla became distinct before
or during the Cambrian, for they all appear fully formed,
without intermediates connecting one form to another."
Douglas Futuyma, Evolutionary Biology, 2nd
ed. (Sunderland, Massachusetts: Sinauer Associates,
Inc., 1986), p. 325.
The
geologist-paleontologist, James W. Valentine writes:
"Each of the phyla that developed durably skeletonized
lineages during this period did so independently, suggesting
that the opportunities for epifaunal life were open
to a wide array of adaptive types. Furthermore, many
of the durably skeletonized phyla appearing in Cambrian
rocks are represented by a number of distinctive subgroups,
classes, or orders, that appear suddenly without known
intermediates." J. W. Valentine, "The Evolution
of Complex Animals", in What Darwin Began,
ed. Laurie Godfrey (Boston: Allyn and Bacon, 1985),
p. 267.
Robert
L. Carroll writes:
"...no more than 20 million years of the early
Cambrian were required for the formation of essentially
modern body plans and the radiation of most of the classes
and orders that were to dominate the remainder of the
Paleozoic and give rise to all phyla present in the
modern biota." (p. 346) He later adds: "By
the end of the Lower Cambrian, all major phyla had appeared,
as had most classes among the marine groups. No new
phyla have appeared in the succeeding 500 million years."
Robert L. Carroll, Patterns and Processes of Vertebrate
Evolution ( Cambridge, England: Cambridge University
Press, 1997), p. 348.
The
British evolutionist, Richard Dawkins, writes:
"...the Cambrian strata of rocks, vintage about
600 million years [evolutionists are now dating the
beginning of the Cambrian at about 530 million years],
are the oldest in which we find most of the major invertebrate
groups. And we find many of them in an advanced state
of evolution, the very first time they appear. It is
as though they were just planted there, without any
evolutionary history." Richard Dawkins, The
Blind Watchmaker (New York: W.W. Norton, 1987),
p. 229.
3) The evolutionary tree of life with the common ancestor
at the bottom which evolved into all the diverse animals
distributed along the branches is not consistent with
the fossil record. Instead the tree should be replaced
by a set of parallel lines, one for each animal phylum,
that have no connections among them, including none
at the beginning.
4)
Major adaptive radiations provide a formidable challenge
to biological evolution. A major adaptive radiation
is the simultaneous appearance of many diverse forms
of a group, for example, birds, with wide geographical
distribution. The appearance of the invertebrate phyla
in the Cambrian was a major adaptive radiation. Besides
the invertebrate phyla, the fossil record shows that
vertebrates have undergone so many major adaptive radiations
that it is the norm for their appearance. Carroll writes:
"the phylogenies of all major vertebrate groups
show an irregular, episodic history of occasional large-scale
radiations followed by the long-term survival of a relatively
small number of basically distinct structural and/or
adaptive types."3 These radiations are
inexplicable by evolution because so many diverse forms
appear virtually simultaneously without fossil evidence
of interrelationships. Major adaptive radiations of
groups of vertebrates are:
a)
Placoderms in the early Devonian. Because they were
heavily armored, jawed fish, intermediates and ancestral
forms should have fossilized but none are found. No
placoderms exist today.
b) Chondrichtyes during the Devonian. They are the cartilaginous
fish such as sharks and rays. Intermediates and ancestors
are unknown.
c) Agnatha Fish in the Silurian. These were jawless
fish with bony skeletons. Intermediates and ancestors
should have fossilized but none are found. Most types
became extinct but hagfish and lampreys are living jawless
fish.
d)Tetrapods in the early Carboniferous. These were many,
diverse forms of four-legged amphibians that are believed
to have evolved from fish. But no fossilized links to
fish have been found and specific interrelationships
of the numerous lineages is unknown.
e) Amniotes in the late Carboniferous. Amniotes are
characterized by their complex reproductive system and
include reptiles, birds and mammals. They are believed
to have evolved from amphibians but their ancestry has
not been determined from the fossil record.
f) Archosaurs in the late Permian. They were reptiles
with diverse sizes and shapes that became extinct in
the Triassic. Some as long as six meters have been found.
g ) Dinosaurs in the late Triassic. Dinosaurs include
the largest terrestrial animals that have ever lived.
Their diversity in size and shape was spectacular. Their
ancestry is unknown and specific interrelationships
of the numerous types is unknown.
h) Teleosts in the late Cretaceous. These are bony fish
approximately 20,000 living species in 35 orders and
409 families. Interrelationships of the higher groups
are unknown.
i) Therian mammals in the late Cretaceous and early
Tertiary. These are placental and marsupial mammals.
When they first appear in the fossil record, they are
very diverse and interrelationships are unknown.
j) Birds in the late Cretaceous and early Tertiary.
There are estimates of 8900 living species in 166 families
and about 27 orders. Fossil evidence is lacking for
establishing the interrelationships of the orders of
birds.
5)
Paleontologist say that the one fact that is most evident
about the fossil record is specie stasis. Consider the
non sequitur by the geneticist Gabriel Dover, calling
"species stasis 'The single most important feature
of macroevolution.'"4 Specie stasis
means that fossils do not show change from when they
first appear to the present time or, for extinct species,
to the time of extinction. This is what Stephen Jay
Gould writes about specie stasis and the absence of
transitional forms; "The history of most fossil
species includes two features inconsistent with gradualism:
1. Stasis. Most species exhibit no directional
change during their tenure on earth. They appear in
the fossil record looking 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'."5
6)
Do the fossils exhibit an obvious continuum of life
forms or as Darwin phrased it, forms of life connected
"by the finest graduated steps"6
that places the efficacy of biological evolution beyond
dispute? It certainly does not. In fact, the fossils
are much like living creatures that are segregated into
distinct groups and do not form a continuum. That is
not to say that some animals are not more similar than
others. But it does say, for example, that the fish
to amphibian to reptile to bird to mammal sequence is
not obvious by any means of comparison.
The
world's foremost evolutionary paleontologist, George
Gaylord Simpson wrote about the 32 orders of mammals:
"The earliest and most primitive known members
of every order already have the basic ordinal characters,
and in no case is an approximately continuous sequence
from one order to another known. In most cases the break
is so sharp and the gap so large that the origin of
the order is speculative and much disputed." G.
G. Simpson, Tempo and Mode In Evolution (New
York: Columbia University Press, 1944), p. 105.
Simpson
also writes: "This regular absence of transitional
forms is not confined to mammals, but is an almost universal
phenomenon, as has long been noted by paleontologists.
It is true of almost all orders of all classes of animals,
both vertebrate and invertebrate. A fortiori, it is
also true of the classes and of the major animal phyla,
and it is apparently also true of analogous categories
of plants." G. G. Simpson, Tempo and Mode In
Evolution (New York: Columbia University Press,
1944), p. 107.
Following
are some assumed major transitions poorly supported
by the fossil record:
a)
The assumed transition from invertebrates to vertebrates
is severely lacking in transitional forms. Some say
the fossil, Pikaia, found in the Burgess Shale and a
member of the chordata phylum is an intermediate.
b)
The assumed transition from dinosaurs to birds is lacking
in transitional forms except for archaeopteryx, an animal
with fully developed, feathered wings and approximately
the size of a crow.
c)
The assumed transition from fish to amphibians assumes
that the hind and fore fins of fish evolved into the
hind and fore feet of amphibians. However, no fossils
have been found with part fin and part feet.
d)
The phylum, chordata, consists of vertebrates and non-invertebrates
with a notochord rather than a backbone. Carroll calls
the vertebrates and non-vertebrate chordates, craniates
and cephalochordates, respectively. He writes that there
is "no fossil evidence of the nature of the transition
between cephalochordates and craniates".7
e)
While most vertebrates have jaws, some such as the lamprey
and hagfish, are jawless. Carroll reports "No fossils
are known that document the origin of the jawed vertebrates."8
f)
There are no fossils that show the development of the
complex reproductive system of amniotes, which include
reptiles, birds and mammals. Carroll writes: "The
early amniotes are sufficiently distinct from all paleozoic
amphibians that their specific ancestry has not been
established."9
g)
Some vertebrates, such as turtles, frogs, bats and pterosaurs,
are so specialized and readily fossilized, that it is
a particular challenge to explain the absence of transitional
fossils.
i) Turtles: Carroll writes "The earliest turtles
are found in the Upper Triassic sediments in Germany.
They are immediately recognizable from the pattern of
the shell, which is closely comparable to that of modern
genera. No trace of earlier or more primitive turtles
has been described, although turtle shells are readily
fossilized and even small pieces are easily recognized."10
ii)
Frogs: Carroll writes "Frogs are the most readily
characterized, because they all adhere to a single skeletal
pattern that is among the most specialized found in
any vertebrate order."11 He adds "When
they first appear in the fossil record during the Jurassic,
both frogs and salamanders appear essentially modern
in their skeletal anatomy."12
iii)
Pterosaurs: Extinct flying reptiles that had membranous
(as opposed to feathered) wings. They include the largest
flying creatures that ever lived with wing spans estimated
at 11 to 12 meters. Fossils of 90 species have been
found, widely distributed on all continents except Antarctica.
They appear in the fossil record with fully-formed wings
and Carroll writes: "They provide little evidence
of their specific ancestry and no evidence of earlier
stages in the origin of flight."13
iv)
Bats: Carroll writes "Bats are among the most specialized
of modern mammals. All are accomplished flyers... and
have a highly developed sonar that enables them to hunt
insects in the dark. Like the pterosaurs, the flight
structure of bats was already highly evolved when they
first appear in the fossil record. The oldest skeleton
of a bat, Icaronycteris from the early Eocene, appears
almost indistinguishable from living bats."14
7) Because of the absence of an obvious continuum of
life forms in the fossil record, transitional forms
are very important in establishing evolutionary patterns.
But what type of fossil is a better indicator that evolution
has occurred? Is it one that has fully formed features
of two diverse groups, such as archaeopteryx with reptile
and bird features? Or is it a fossil with a feature
that is in flux between two groups, such as a feature
that is partly reptile scale and partly feathered wing?
or a feature that is partly fish fin and partly amphibian
leg? Obviously the latter is a much stronger indicator
that evolution has occurred. Does the fossil record
contain these transitional fossils? The evolutionary
paleontologist R. Carroll gives the answer when he writes
about "the rapid evolution that characterizes the
early stages in the elaboration of new structures"15
such as wings, legs and the amniotic reproductive system.
He assumes “rapid evolution” to explain
the absence of fossils that show these new structures
in a state of development. Carroll lists 21 Major Structural
and Physiological Changes in the History of Vertebrates
and the origin of all is unknown.16
There are no fossils that are scientifically demonstrable
transitional forms. Because the gradual changes that
Darwin envisioned are lacking, scientific verification
requires the impossible task of specifying the sequence
of mutations that changed the hypothesized ancestor
into the hypothesized descendent. Even if fossils had
all their DNA intact, scientists could not determine
if such sequences had occurred.
"The
fossil record with its abrupt transitions offers no
support for gradual change...." In the same article
Gould writes: 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, Natural History 86(6):
22-30 (1977).
Again
Gould writes:
The extreme rarity of transitional forms in the fossil
record persists is the trade secret of paleontology.
The evolutionary tree 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 fossils. S. J. Gould, Natural History, 86(5):
13 (1977).
Missing links in the sequence of fossil evidence were
a worry to Darwin. He felt sure they would eventually
turn up, but they are still missing and seem likely
to remain so. E. R. Leach, Nature 293:19 (1981).
1
C. Darwin, The Origin of Species (1859).
2 D. T. Gish, Evolution: The Fossils Still Say NO!,
( El Cajon, California: Institute for Creation Research,
1995), p. 54.
3R.
L. Carroll, Vertebrate Paleontology and Evolution,
( New York: W. H. Freeman and Co., 1988), p. 581.
4 R. Lewin, "Evolutionary Theory Under Fire",
in Science 210:883-887 (1980).
5
S. J. Gould, Natural History, 86(5): 13 (1977).
6 C. Darwin, The Origin of Species (1859).
7R.
L. Carroll, Patterns and Processes of Vertebrate
Evolution ( Cambridge, England: Cambridge University
Press, 1997), p. 296
8
Ibid., p. 296.
9
R. L. Carroll, Vertebrate Paleontology and Evolution,
( New York: W. H. Freeman and Co., 1988), p. 198.
10
Ibid., p. 207.
11 Ibid., p. 181.
12 Ibid., p. 180.
13 Ibid., p. 336.
14 Ibid., p. 463.
15 Ibid., p. 578.
16 Ibid., p. 579.
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