Objection #3: Evolution Explains Life, So God Isn't Needed (2001)
(Interview w/ Walter L. Bradley, Ph.D.)
This objection is extremely poorly phrased. From a reading of the chapter, it is clear that Strobel's phrasing, "Evolution Explains Life" means more specifically, evolution explains the origin of life or how evolution was able to give rise to life from non-life. Unfortunately for Strobel, this is a non-issue because evolution explains no such thing, nor does it purport to. Strobel smugly points out that Darwin, "didn't really have a good idea of how life arose," (94) and didn't look into the issue with much depth. This is because the problem of how the first life began is totally irrelevant to Darwin's theory of natural selection. Evolution and natural selection explain how organisms change over time. As far as origins are concerned, the only thing that is important to evolution is that life, somehow or other, did in fact begin. The issue of how life arose from non-life is called "abiogenesis" and should be treated separately from evolution.
So "Objection #3" really isn't an objection at all, but rather an excuse for Strobel to argue: "Since we can't account for the origin of life, God must've been behind it." But this is just an appeal to ignorance, attributing that which we can't explain to God and converting Him into a three letter word meaning "I don't know." Almost the entirety of the chapter is devoted to the problem of abiogenesis, and I will discuss that a bit more in short order. But first, there are a few actual evolution criticisms to address, as well as an issue of Strobel's journalistic integrity.
Throughout the chapter Strobel and Bradley beset us with implications that are made explicit near the end with this quote from Bradley: "Today it takes a great deal of faith to be an honest scientist who is an atheist" (111). Thus he has painted a picture of a scientific community where all reasonable and honest scientists have conceded the existence of an Intelligent Creator, while a few rebels desperately hang on to outmoded naturalistic explanations out of sheer stubbornness. This is completely disingenuous and Strobel should be ashamed of such a misrepresentation. The fact of the matter is that there are tons of honest men and women recognized for excellence in their scientific fields who reject the notion of God. Furthermore, the vast majority of scientists who do believe in God consider creationism to be complete rubbish. This is why creationists are forced to always bring up the same people (Behe, Denton) and either misquote or quote out of context everyone else, from Einstein to Asimov, to support their position . Of course, the most important point of all is that what specific scientists say or believe does not determine truth. On this bogus tactic, in fact, see Richard Carrier on The Fallacy of Appeal to Authority and The Fallacy of Appeal to Reverence.
Strobel does launch a couple meager attacks on evolution. Before I address them specifically, it is vital to note three points: (1) The Creationist's False Dichotomy: Virtually every aspect of "creation science" involves mounting an attack on evolution. What I think they fail to realize is that, even if these attacks were wholly substantiated and evolution was demonstrably false in every way, it would do nothing to uphold the validity of creationism. Even if evolution is false, it's not as if the Bible's creation story is the only alternative. (2) God And Evolution Aren't Incompatible: If you recognize evolution as true, it doesn't mean you have to toss God out on the front stoop. Just because evolution occurred, doesn't mean God isn't behind it all. As a matter of fact, there are millions of Christians who believe the existence of God and evolution both are true, and it causes them no problems whatsoever. (3) Scientific Debate is Not a Weakness: Creationists are pleased by nothing more than when scientists disagree on some evolutionary issue or when new evidence overturns an old conclusion. They seem to perceive this as a weakness, when in fact it's one of science's greatest strengths. The fact that science has an error-correcting machinery built into its method, allowing even the most strongly supported issues to be open to debate, and old conclusions to be repeatedly tested in the light of new evidence, should inspire great confidence in science's ability to determine the truth. On the other hand, religion's dogmatic assertion that it has a special privilege to the one and only changeless truth, which cannot be tested or questioned, should at least raise your eyebrow, if not scare the living hell out of you.
As for his attacks on evolution: Strobel regurgitates the tired old creationist argument that there is "a paucity of fossil evidence for the transitions between various species of animals" (91). This is blatantly false. When Strobel couldn't find any transitional fossils, I guess he overlooked these:
Transition from primitive jawless fish to sharks, skates, and rays:
- Cladoselachians (e.g., Cladoselache).
- Hybodonts (e.g. Hybodus)
- Heterodonts (e.g. Heterodontus)
- Hexanchids (e.g. Chlamydoselache)
Transition from primitive bony fish to holostean fish:
- Palaeoniscoids (e.g. Cheirolepis); living chondrosteans such as Polypterus and Calamoichthys, and also the living acipenseroid chondrosteans such as sturgeons and paddlefishes.
- Primitive holosteans such as Semionotus.
Transition from holostean fish to advanced teleost fish:
- Leptolepidomorphs, esp. Leptolepis, an excellent holostean-teleost intermediate
- Elopomorphs, both fossil and living (tarpons, eels)
- Clupeomorphs (e.g. Diplomystus)
- Osteoglossomorphs (e.g. Portheus)
Transition from primitive bony fish to amphibians:
- Paleoniscoids again (e.g. Cheirolepis)
- Osteolepis -- one of the earliest crossopterygian lobe-finned fishes, still sharing some characters with the lungfish (the other group of lobe-finned fish). Had paired fins with a leg-like arrangement of bones, and had an early-amphibian-like skull and teeth.
- Eusthenopteron (and other rhipidistian crossopterygian fish) -- intermediate between early crossopterygian fish and the earliest amphibians. Skull very amphibian-like. Strong amphibian-like backbone. Fins very like early amphibian feet.
- Icthyostegids (such as Icthyostega and Icthyostegopsis) -- Terrestrial amphibians with many of Eusthenopteron's fish features (e.g., the fin rays of the tail were retained). Some debate about whether Icthyostega should be considered a fish or an amphibian; it is an excellent transitional fossil.
- Labyrinthodonts (e.g., Pholidogaster, Pteroplax) -- still have some icthyostegid features, but have lost many of the fish features (e.g., the fin rays are gone, vertebrae are stronger and interlocking, the nasal passage for air intake is well defined.)
Transition from amphibians to reptiles:
- Seymouriamorph labyrinthodonts (e.g. Seymouria) -- classic labyrinthodont skull and teeth, with reptilian vertebrae, pelvis, humerus, and digits; amphibian ankle.
- Cotylosaurs (e.g. Hylonomus, Limnoscelis) -- slightly amphibian skull (e.g. with amphibian-type pineal opening), with rest of skeleton classically reptilian.
- The cotylosaurs gave rise to many reptile groups of tremendous variety. I won't go into the transitions from cotylosaurs to the advanced anapsid reptiles (turtles and possibly mesosaurs), to the euryapsid reptiles (icthyosaurs, plesiosaurs, and others), or to the lepidosaurs (eosuchians, lizards, snakes, and the tuatara), or to most of the dinosaurs, since I don't have infinite time. Instead I'll concentrate on the synapsid reptiles (which gave rise to mammals) and the archosaur reptiles (which gave rise to birds).
Transition from reptiles to mammals:
- Pelycosaur synapsids -- classic reptilian skeleton, intermediate between the cotylosaurs (the earliest reptiles) and the therapsids (see next)
- Therapsids (e.g. Dimetrodon) -- the numerous therapsid fossils show gradual transitions from reptilian features to mammalian features. For example: the hard palate forms, the teeth differentiate, the occipital condyle on the base of the skull doubles, the ribs become restricted to the chest instead of extending down the whole body, the legs become "pulled in" instead of sprawled out, the ilium (major bone of the hip) expands forward.
- Cynodont theriodonts (e.g. Cynognathus) -- very mammal-like reptiles. Or is that reptile-like mammals? Highly differentiated teeth (a classic mammalian feature), with accessory cusps on cheek teeth; strongly differentiated vertebral column (with distinct types of vertebrae for the neck, chest, abdomen, pelvis, and tail -- very mammalian), mammalian scapula, mammalian limbs, mammalian digits (e.g. reduction of number of bones in the first digit). But, still has unmistakably reptilian jaw joint.
- Tritilodont theriodonts (e.g. Tritylodon, Bienotherium) -- skull even more mammalian (e.g. advanced zygomatic arches). Still has reptilian jaw joint.
- Ictidosaur theriodonts (e.g. Diarthrognathus) -- has all the mammalian features of the tritilodonts, and has a double jaw joint; both the reptilian jaw joint and the mammalian jaw joint were present, side-by-side, in Diarthrognathus's skull. A really stunning transitional fossil.
- Morganucodonts (e.g. Morganucodon) -- early mammals. Double jaw joint, but now the mammalian joint is dominant (the reptilian joint bones are beginning to move inward; in modern mammals these are the bones of the middle ear).
- Eupantotheres (e.g. Amphitherium) -- these mammals begin to show the complex molar cusp patterns characteristic of modern marsupials and eutherians (placental mammals). Mammalian jaw joint.
- Proteutherians (e.g. Zalambdalestes) -- small, early insectivores with molars intermediate between eupantothere molars and modern eutherian molars.
- Those wondering how egg-laying reptiles could make the transition to placental mammals may wish to study the reproductive biology of the monotremes (egg-laying mammals) and the marsupials. The monotremes in particular could almost be considered "living transitional fossils". [see Peter Lamb's suggested marsupial references at end]
Transition from reptiles to birds:
- Lisboasaurus estesi and other "troodontid dinosaur-birds" -- a bird-like reptile with very bird-like teeth (that is, teeth very like those of early toothed birds [modern birds have no teeth]). May not have been a direct ancestor; may have been a "cousin" of the birds instead.
- Protoavis -- this is a highly controversial fossil that may or may not be an extremely early bird. Not enough of the fossil was recovered to determine if it is definitely related to the birds, or not. I mention it in case people have heard about it recently.
- Archeopteryx -- reptilian vertebrae, pelvis, tail, skull, teeth, digits, claws, sternum. Avian furcula (wishbone, for attachment of flight muscles), forelimbs, and lift-producing flight feathers. Archeopteryx could probably fly from tree to tree, but couldn't take off from the ground, since it lacked a keeled breastbone (for attachment of large flight muscles) and had a weak shoulder (relative to modern birds).
- "Chinese bird" [I don't know what name was given to this fossil] -- A fossil dating from 10-15 million years after Archeopteryx. Bird-like claws on the toes, flight-specialized shoulders, fair-sized sternal keel (modern birds usually have large sternal keel); also has reptilian stomach ribs, reptilian unfused hand bones, & reptilian pelvis. This bird has a fused tail ("pygostyle"), but I don't know how long it was, or if it was all fused or just part of it was fused.
- "Las Hoyas bird" [I don't know what name was given to this fossil] -- This fossil dates from 20-30 m.y. after Archeopteryx. It still has reptilian pelvis & legs, with bird-like shoulder. Tail is medium-length with a fused tip (Archeopteryx had long, unfused tail; modern birds have short, fused tail). Fossil down feather was found with the Las Hoyas bird.
- Toothed Cretaceous birds, e.g. Hesperornis and Ichthyornis. Skeleton further modified for flight (fusion of pelvis bones, fusion of hand bones, short & fused tail). Still had true socketed teeth, which are missing in modern birds.
- [note: a classic study of chicken embryos showed that chicken bills can be induced to develop teeth, indicating that chickens (and perhaps other modern birds) still retain the genes for making teeth.]
Now, on to some of the classes of mammals.
Transitional fossils from early eutherian mammals to primates:
- Early primates -- paromomyids, carpolestids, plesiadapids. Lemur-like clawed primates with generalized nails.
- Notharctus, an early Eocene lemur
- Parapithecus, a small Old World monkey (Oligocene)
- Propliopithecus, a small primate intermediate between Parapithecus and the more recent O.W. monkeys. Has several ape-like characters.
- Aegyptopithecus, an early ape.
- Limnopithecus, a later ape showing similarities to the modern gibbons.
- Dryopithecus, a later ape showing similarities to the non-gibbon apes.
- Ramapithecus, a dryopithecine-like ape showing similarities to the hominids but now thought to be an orang ancestor.
- Australopithecus spp., early hominids. Bipedal.
- Homo habilis.
- Homo erectus. Numerous fossils across the Old World.
- Homo sapiens sapiens. This is us. (NB: "Cro-magnon man" belongs here too. Cro-magnons were a specific population of modern humans.)
- Homo sapiens neanderthalensis (not on the direct line to H. sapiens sapiens, but worth mentioning).
- [I haven't described these fossils in detail because they're fairly well covered in any intro biology text, or in any of several good general- interest books on human evolution.]
Transitional fossils from early eutherian mammals to rodents:
- Paramyids, e.g. Paramys -- early "primitive" rodent
- Paleocastor -- transitional from paramyids to beavers
- [yick. I was going to summarize rodent fossils but Paramys and its friends gave rise to 5 enormous and very diverse groups of rodents, with about ten zillion fossils. Never mind.]
Transitional fossils among the cetaceans (whales & dolphins):
- Pakicetus -- the oldest fossil whale known. Only the skull was found. It is a distinct whale skull, but with nostrils in the position of a land animal (tip of snout). The ears were partially modified for hearing under water. This fossil was found in association with fossils of land mammals, suggesting this early whale maybe could walk on land.
- Basilosaurus isis -- a recently discovered "legged" whale from the Eocene (after Pakicetus). Had hind feet with 3 toes and a tiny remnant of the 2nd toe (the big toe is totally missing). The legs were small and must have been useless for locomotion, but were specialized for swinging forward into a locked straddle position -- probably an aid to copulation for this long-bodied, serpentine whale.
- Archaeocetes (e.g. Protocetus, Eocetus) -- have lost hind legs entirely, but retain "primitive whale" skull and teeth, with forward nostrils.
- Squalodonts (e.g. Prosqualodon) -- whale-like skull with dorsal nostrils (blowhole), still with un-whale-like teeth.
- Kentriodon, an early toothed whale with whale-like teeth.
- Mesocetus, an early whalebone whale
- [note: very rarely a modern whale is found with tiny hind legs, showing that some whales still retain the genes for making hind legs.]
Transitional fossils from early eutherian mammals to the carnivores:
- Miacids (e.g. Viverravus and Miacis) -- small weasel-like animals with very carnivore-like teeth, esp. the carnassial teeth.
- Arctoids (e.g. Cynodictis, Hesperocyon) -- intermediate between miacids and dogs. Limbs have elongated, carnassials are more specialized, braincase is larger.
- Cynodesmus, Tomarctus -- transitional fossils between arctoids and the modern dog genus Canis.
- Hemicyon, Ursavus -- heavy doglike fossils between the arctoids and the bears.
- Indarctos -- early bear. Carnassial teeth have no shearing action, molars are square, short tail, heavy limbs. Transitional to the modern genus Ursus.
- Phlaocyon -- a climbing carnivore with non-shearing carnassials, transitional from the arctoids to the procyonids (raccoons et al.)
Meanwhile back at the ranch,
- Plesictis, transitional between miacids (see above) and mustelids (weasels et al.)
- Stenoplesictis and Palaeoprionodon, early civets related to the miacids (see above)
- Tunguricits, transitional between early civets and modern civets
- Ictitherium, transitional between early civets to hyenas
- Proailurus, transitional from early civets to early cats
- Dinictis, transitional from early cats to modern "feline" cats
- Hoplophoneus, transitional from early cats to "saber-tooth" cats
Transitional fossils from early eutherians to hoofed animals:
- Arctocyonid condylarths -- insectivore-like small mammals with classic mammalian teeth and clawed feet.
- Mesonychid condylarths -- similar to the arctocyonids, but with blunt crushing-type cheek teeth, and flattened nails instead of claws.
- Late condylarths, e.g. Phenocodus -- a fair-sized animal with hoofs on each toe (all toes were present), a continuous series of crushing-type cheek teeth with herbivore-type cusps, and no collarbone (like modern hoofed animals).
- Transitional fossils from early hoofed animals to perissodactyls:
- [Perissodactyls are animals with an odd number of toes; most of the weight is borne by the central 3rd toe. Horses, rhinos, tapirs.]
- Tetraclaeonodon -- a Paleocene condylarth showing perissodactyl-like teeth
- Hyracotherium -- the famous "dawn horse", an early perissodactyl, with more elongated digits and interlocking ankle bones, and slightly different tooth cusps, compared to to Tetraclaeonodon. A small, doggish animal with an arched back, short neck, and short snout; had 4 toes in front and 3 behind. Omnivore teeth.
- [The rest of horse evolution will be covered in an upcoming "horse fossils" post in a few weeks. To whet your appetite:]
- Orohippus -- small, 4/3 toed, developing browser tooth crests
- Epihippus -- small, 4/3 toed, good tooth crests, browser
- Epihippus (Duchesnehippus) -- a subgenus with Mesohippus-like teeth
- Mesohippus -- 3 toed on all feet, browser, slightly larger
- Miohippus -- 3 toed browser, slightly larger [gave rise to lots of successful three-toed browsers]
- Parahippus -- 3 toed browser/grazer, developing "spring foot"
- 'Parahippus' leonensis -- a Merychippus-like species of Parahippus
- 'Merychippus' gunteri -- a Parahippus-like species of Merychippus
- 'Merychippus' primus -- a more typical Merychippus, but still very like Parahippus.
- Merychippus -- 3 toed grazer, spring-footed, size of small pony (gave rise to tons of successful three-toed grazers)
- Merychippus (Protohippus) -- a subgenus of Merychippus developing Pliohippus-like teeth.
- Pliohippus & Dinohippus -- one-toed grazers, spring-footed
- Equus (Plesippus) -- like modern equines but teeth slightly simpler.
- Equus (Hippotigris), the modern 1-toed spring-footed grazing zebras.
- Equus (Equus), the modern 1-toed spring-footed grazing horses & donkeys. [note: very rarely a horse is born with small visible side toes, indicating that some horses retain the genes for side toes.]
- Hyrachyids -- transitional from perissodactyl-like condylarths to tapirs
- Heptodonts, e.g. Lophiodont -- a small horse-like tapir, transitional to modern tapirs
- Protapirus -- a probable descendent of Lophiodont, much like modern tapirs but without the flexible snout.
- Miotapirus -- an almost-modern tapir with a flexible snout, transitional between Protapirus and the modern Tapirus.
- Hyracodonts -- early "running rhinoceroses", transitional to modern rhinos
- Caenopus, a large, hornless, generalized rhino transitional between the hyracodonts and the various later groups of modern & extinct rhinos.
- Transitional fossils from early hoofed animals to some of the artiodactyls (cloven-hoofed animals):
- Dichobunoids, e.g. Diacodexis, transitional between condylarths and all the artiodactyls (cloven-hoofed animals). Very condylarth-like but with a notably artiodactyl-like ankle.
- Propalaeochoerus, an early pig, transitional between Diacodexis and modern pigs.
- Protylopus, a small, short-necked, four-toed animal, transitional between dichobunoids and early camels. From here the camel lineage goes through Protomeryx, Procamelus, Pleauchenia, Lama (which are still alive; these are the llamas) and finally Camelus, the modern camels.
- Archeomeryx, a rabbit-sized, four-toed animal, transitional between the dichobunoids and the early deer. From here the deer lineage goes through Eumeryx, Paleomeryx and Blastomeryx, Dicrocerus (with antlers) and then a shmoo of successful groups that survive today as modern deer -- muntjacs, cervines, white-tail relatives, moose, reindeer, etc., etc.
- Palaeotragus, transitional between early artiodactyls and the okapi & giraffe. Actually the okapi hasn't changed much since Palaeotragus and is essentially a living Miocene giraffe. After Palaeotragus came Giraffa, with elongated legs & neck, and Sivatherium, large ox-like giraffes that almost survived to the present.
So, there's a partial list of transitional fossils. And this really only scratches the surface, since it doesn't include all groups that have no surviving relatives, didn't discuss modern amphibians or reptiles, left out most of the birds, ignored the diversity in modern fish, didn't discuss the bovids or elephants or rodents or many other mammal groups.... I hope this gives a taste of the richness of the fossil record and the abundance of transitional fossils between major vertebrate taxa .
Strobel then takes up the "irreducible complexity" argument espoused by Michael Behe (the same guy, yet again). This is nothing more than the antiquated argument from design wrapped up in the raiment of modern molecular biology. The problem with Behe's irreducibly complex systems is that their irreducibility is based on the assumption that a particular molecular component's function has not changed over time. But we have every reason to suspect that component functions can and do change. There is a wealth of criticism for Behe available: see the Secular Web's library on Michael Behe.
Before I totally let Behe off the hook, I'd like to point out another of Strobel's spurious journalistic tactics. He describes Behe's book, Darwin's Black Box, as "award-winning" (92). Now, he doesn't explicitly say what kind of award this was, yet I believe he expected the reader to presume this was an award for scientific merit from a scientific organization--and I think most readers probably did. However, the distinction was actually bestowed upon Darwin's Black Box at the Christianity Today Book Awards . Shouldn't Strobel have mentioned that little fact?
The Building Blocks Of Life
The entire Bradley interview itself is concerned with abiogenesis, which, I would again like to note, is irrelevant to evolution. Nevertheless, this interview is also flawed. Bradley informs Strobel that the initial conditions were assumed in the famous Miller-Urey Experiment in which amino acids were created by simulating earth's early environment and adding electrical energy to the system. Strobel makes a great to-do of Bradley's revelation (to him) that Miller assumed an environment rich in the elements which he used for the simulation. They then dismiss the entire experiment (95-7).
Firstly, just because Strobel couldn't recognize that the experiment is based on a hypothesis, doesn't mean everyone else is so blind. I don't believe Miller attempted to hide the fact that he was guessing as to the composition of the early earth's atmosphere. Secondly, we still have an experiment where the building blocks of life formed spontaneously from non-life conditions. Even if those were not early earth's conditions, it still says something about the possibility of abiogenesis.
Assembling A Cell
Bradley extols the complexity of the cell and declares the origin of life to be an unsolved problem. He then goes on to refute six theories of abiogenesis (95-106).
Bradley is right that the cell is complex and the origin of life unknown. As for the six theories, I am not qualified to discuss them specifically. However, there are several considerations to keep in mind when evaluating abiogenesis theories (and refutations):
To begin with, to actually calculate the 'odds of life evolving by chance' one must calculate the odds of the first living (i.e. replicating) organism arising by chance. But no one knows what that first organism was, for it naturally had no bones and thus left no fossils, and it certainly would have been vastly overpowered and driven to extinction by its more advanced children who were born after successive mutation and selection. It is not even known if this first life was DNA-based, much less how complex it was. But even if we could estimate the simplest possible biochemical replicator, the task would only be beginning. The odds of such a replicator forming by chance would not be based on its complexity alone. The chances would have to be calculated based on the number of materials available (e.g. more than one different molecule may serve the same purpose at any given point in a chain), the probability that they will form into collectives (e.g. amino-acids naturally chain, water molecules do not), and the number of tests (e.g. the number of chemical reactions that occur in a given environment, and the number of times any kind of chain or collective is formed in the population). In other words, to actually calculate the odds of 'life' developing from inanimate matter, one must be acquainted not only with a vast arrangement of data and know how to estimate all the statistical relationships involved, but one must even know things that no one on Earth presently knows, or ever may know.
Therefore, any one who claims to be able to tell you about the likelihood (on unlikelihood) of a particular abiogenesis theory should be treated with the utmost suspicion.
The Most Reasonable Inference
Bradley suggests that an Intelligent Designer is, indeed, the most reasonable inference (107-9).
Bradley says, "If there isn't a natural explanation and there doesn't seem to be the potential of finding one, then I believe it's appropriate to look at a supernatural explanation" (108). But this solves nothing, because Bradley is simply handing off the problem to God, who can explain anything. It is not a reasonable inference because it is based on ignorance. To Bradley's credit, it should be noted that he claims, "what I've found is absolutely overwhelming evidence that points to an Intelligent Designer" (109). To his detriment, it should be noted that he fails to produce any such evidence.
Reasoning By Analogy
Bradley would have us believe that, "we can legitimately use analogical reasoning to conclude that the remarkable information sequences in DNA...had an intelligent cause" (109-11). He trots out a couple of analogies for just this purpose.
Analogical reasoning is useful as an explanatory tool, allowing us to understand more complex issues by their comparison to simpler ones. However, because analogies do, by nature, simplify an issue, their conclusions are often specious. If a Christian doubts this, I invite them to examine the following:
1. David Koresh claimed to be God, therefore he was a lunatic.
2. Jesus Christ claimed to be God, therefore he was also a lunatic.
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