The Non-Transitions in ‘Human Evolution’—on Evolutionists’ Terms

Commonly, apologists for evolution put up a bold front and try to deny that the tree of evolution is full of holes (or, more accurately, is mostly holes with just twigs at the end). It is therefore instructive whenever an article appears that is written by evolutionists who candidly acknowledged the major discontinuities in (alleged) evolutionary sequences. Recently, Wood and Collard have written just such an article on human evolution.1

To follow their statements, the reader must be familiar with some relatively recent changes in the relevant taxonomy and nomenclature, e.g. in this report, I follow Wood and Collard1 in using ‘hominin’ and ‘australopith’. However, usage of these terms reflects complexity of the taxonomy. It would be logical to use ‘hominin’ to refer to members of the subfamily Homininae, i.e. modern humans and their alleged post-australopithecine precursors; and ‘australopith’ to refer to members of the subfamily Australo- pithecinae.2 Both subfamilies are classified in the family Hominidae (‘hominids’).2 But Wood and Collard often seem to use the term ‘hominin’ to mean ‘hominid’.

Thus, Australopithecus boisei, A. aethiopicus, and A. robustus are now assigned to the genus Paranthropus. Australopithecus sensu lato (i.e. in the broad sense) now applies to the remaining australopith specimens, A. africanus and A. anamensis. Praeanthropus is the new accepted generic name for specimens like ‘Lucy’, previously classified as A. afarensis. Australopithecus, Paranthropus, Praeanthropus and Ardipithecus are all considered australopith genera.3

The trend seems to be to elevate Neandertal man to a separate species once again.

In comparable manner, Homo habilis has now been split up into Homo rudolfensis and Homo habilis sensu lato. What used to be called ‘early Homo erectus’ has now been split off and elevated to a separate species, Homo ergaster. What remains is called Homo erectus sensu lato. Finally, the trend seems to be to elevate Neandertal man to a separate species once again—Homo neanderthalensis and Homo heidelbergensis as distinct from Homo sapiens sensu lato. This is despite the facts that biochemical evidences for the distinctness of Neandertal man are not well established,4 that a nearly complete skeleton of a four-year-old boy had a mixture of Neandertal and modern H. sapiens traits, implying interbreeding,5^,6 and that ‘Neanderthals were fully cultural human beings, with symbol-aided communication’.7 However, Wood and Collard point out that some anthropologists think that most or all of the above-mentioned species can be subsumed within our own species, Homo sapiens. 8

The habilines (Homo rudolfensis and Homo habilis sensu lato) are of questionable taxonomic validity, as pointed out by Lubenow.9 This owes largely to the uncertain assignment of fragmentary remains to the same taxon. Furthermore, as shown by Wood and Collard,1 they do not fit into the genus Homo at all. To the contrary:

‘The obvious taxonomic alternative, which is to transfer one or both of the taxa to one of the existing early hominin genera, is not without problems, but we recommend that, for the time being, both H. habilis and H. rudolfensis should be transferred to the genus Australopithecus.’10

Some evolutionists try to deny the fact of gross non-transitions in evolution by arguing that the taxonomic names themselves cover up a great deal of presumed evolutionary change. For instance, they may claim that Australopithecus and Homo only seem to be separate and distinct entities, but in actuality the two genera grade into each other, and thus the names Australopithecus and Homo are merely arbitrary divisions of an evolutionary continuum of primitive-to-advanced hominids. Nothing could be further from the truth! As we shall see, a variety of statistical analyses have been performed, and these show that, for the most part, australopiths and Homo each consist of a mutually-distinct cluster of morphological attributes. And, if anything, (and as discussed above) there probably exists a proliferation of artificial species reflecting trivial differences rather than a small number of specific names, each subsuming an excessive amount of variation.

Of course, the evolutionist apologist can always single out particular traits and claim that they are gradational within presumed human evolution. But the total picture tells an entirely different story. Let us now take a closer look at how the australopiths and members of the genus Homo each show a constellation of traits that clearly set off one from the other, and, furthermore, how the few traits which seem gradational are actually of marginal significance.

Table 1: Summary of the results of analyses of characteristics of fossil Homo species [After Table 7 in Wood and Collard, 3]. 1) body size, 2) body shape, 3) locomotion, 4) jaws and teeth, 5) development and 6) brain size. H = like modern humans, A = australopith-like, I = intermediate ? = data unavailable.

In order to fend off the usual bogus anti-creationist accusations of quoting out of context, Table 1 (above) has been reproduced from Table 7 in Wood and Collard exactly as it appears in their work. As can be seen, only one major constellation of traits in the specimens in question is in fact characterized as I (intermediate) between australopiths and Homo sapiens. All of the others are either unknown, clear-cut australopith in morphology, or clear-cut Homo sapiens in morphology. Now, had the hominins actually been a series of transitional forms gradually progressing from australopith to modern Homo sapiens (as commonly portrayed in textbooks), many if not most of the entries in Table 1 would instead be I (intermediate).

But it gets even worse for the evolutionist. Note that the individual hominins do not even qualify as a mosaic of australopith and Homo sapiens attributes. There is no increase in the number of human traits in the ‘series’. Most or all of the six constellations of traits dichotomize sharply along the lines of all-australopith or all Homo sapiens in terms of morphology.

Let us now take a closer look at the features which are generalized in Table 1.

1. and 2. Body size and shape

There exists a demonstrably non-gradational deployment of body shapes and sizes among the hominins:

‘Body size in primates correlates with numerous ecological and life history variables, including population density, home range size, social organization, and age at first breeding, whereas body shape is closely linked to temperature regulation, water balance, and habitat … The data show a clear separation between H. sapiens (excluding secondarily dwarfed populations), H. neanderthalensis, H. erectus, H heidelbergensis, and H. ergaster, on one hand, and A. africanus, P. boisei, P. robustus, Praeanthropus africanus and H. habilis, on the other … Praeanthropus africanus was, in overall size and limb proportions, more similar to living great apes than to modern humans.’11 (Emphasis added)

As for H. rudolfensis, ‘[t]here are no postcranial fossils that can be reliably linked to’ this taxon.12

Creationists have long called attention to the evolutionists’ old error of portraying Neandertal man as apelike and stooped-over. Wood and Collard also acknowledge this past misrepresentation of Neandertal man, and stress the fact that the posture, foot structure, and limb and muscle function were essentially the same as that of modern man.12

3. Locomotion

There is a lively controversy on the locomotory capabilities of the australopiths. Wood and Collard cite a series of recent studies, some of which contend that australopiths were bipedal, and others which contend that they combined a quasi-bipedalism with tree-climbing adaptations.12 Mehlert has summarized evidences against human-like bipedal locomotion in australopiths.13

Irrespective of the exact details of australopith locomotion, however, there is no evidence of a gradational change from its idiosyncratic locomotion to that kind of bipedalism which is clearly characteristic of creatures correctly assigned to the genus Homo:

‘The relevant evidence for H. ergaster suggests that it was an obligate terrestrial biped much like H. sapiens. Remains of the lower limb and pelvis indicate that it had a commitment to bipedal locomotion that was equivalent to that seen in modern humans, and there is no evidence in the upper limb bones for the sort of climbing abilities possessed by the australopiths and H. habilis.’14

As a result of this, the recurring and sharp dichotomy (between australopiths–habilines on one hand and true humans on the other hand) surfaces once again:

‘Thus, on the basis of the locomotor inferences that can be made from their postcranial morphology, the fossil hominins [sic—hominids2] can be divided into two groups. The first group displays a mixed strategy, combining a form of terrestrial bipedalism with an ability to climb proficiently. This group comprises Praeanthropus, Australopithecus, Paranthropus, and H. habilis. The second group consists of H. erectus, H. ergaster, H. heidelbergensis, and H. neanderthalensis and is characterized by a commitment to modern human-like terrestrial bipedalism and a very limited arboreal facility. The hypothesized contrast between the locomotor repertoires of the two groups is supported by a recent computed [sic] tomography study of the hominin bony labyrinth).[15]’12(Emphasis added)

4. Jaws and teeth

Eleven variables of the masticatory apparatus were subject to statistical analysis. Differences between different hominins were quantified according to Euclidean distances derived from statistical measure. Using the eleven cranio-facial variables, Wood and Collard demonstrate that Homo ergaster, Homo erectus, and Homo neanderthalenthis are all very similar to Homo sapiens and all very different from Australopithecus africanus and Paranthropus (formerly Australopithecus) robustus.10 Simultaneously, the problematic habilines (H. rudolfensis and H. habilis) are very dissimilar to Homo sapiens but quite similar to both A. africanus and P. robustus.

5. Development

What if we were to compare the developmental ‘schedules’ of the hominins against that of modern apes and humans, respectively? The results by now are predictable, and they speak for themselves:

‘Recent analyses of dental and femoral development in the fossil hominins have indicated that Australopithecus is more similar to the African apes in its rate of development than it is to modern humans, whereas the developmental schedules of H. ergaster and H. neanderthalensis are more similar to H. sapiens than they are to the developmental schedules of G. gorilla and P. troglodytes …Thus, both H. habilis and H. rudolfensis are apparently more similar in their dental development to the African great apes than they are to H. sapiens, which indicates that neither species is likely to have displayed an extended period of dependence.’12

6. Brain size

Here at last is one trait which superficially seems to be a friend of the evolutionist. Brain size does seem to show a gradational increase throughout the hominin lineage, especially when body size is taken into account (Table 1). But this is of doubtful significance, as shown below.

Creationists have long called attention to the fact that there are modern humans with small brains who are nevertheless of normal intelligence and of full humanity. Evolutionists are also belatedly recognizing the limitations of neuro-anatomical features, although from a different angle:

‘The Cerebral Rubicon is problematic, because absolute cranial capacity is of questionable biological significance.[16] Likewise there is compelling evidence that language function cannot be reliably inferred from the gross appearance of the brain, and that the language-related parts of the brain are not as well localized as earlier studies had implied.[17]’3

Conclusions

Typical textbooks show the following progression: an apelike knuckle-walking primate, followed by forms which are progressively larger, progressively more bipedal, and progressively more intelligent—all culminating in us modern humans. As we have seen, the scientific evidence shows no such thing.

The relevant evidence clearly shows that Homo sapiens sensu lato is a separate and distinct entity from the other hominids. No overall evolutionary progression is to be found. Adam and Eve, and not the australopiths/habilines, are our actual ancestors. As pointed out by other creationists [e.g., Lubenow9], Homo ergaster, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis can best be understood as racial variants of modern man—all descended from Adam and Eve, and most likely arising after the separation of people groups after Babel.