Tag Archives: Human evolution

“Science & Human Origins” Informational Review

Science & Human Origins cover0001Science & Human Origins, a Discovery Institute Press book (2012) by Ann Gauger, Douglas Axe, and Casey Luskin, is a much needed summary of the difficult to understand sciences that are used in the study of human origins and evolution.  The scientific methods used may not be the primary problem in understanding, however, but instead, the politics and emotionalism involved.  For the person who wants to find anything beyond the “party line” in regards to the science, and what we actually know of the hominin (previously “hominid”) fossil record, a source like this may be your best hope.  Popular textbooks, museum displays, and magazines fail to present pertinent facts, and quotes found in this book by the highest of academics in the field can leave you assured of the authors’ assessment.

This small book is not perfect, in my view.  I found chapter two, on one explanation of how there is not enough time to account for the amount of evolution that has taken place, difficult to understand.  Maybe you will not have this difficulty.  It just seems like there is something missing to me.  The way the book is put together seems disjointed to me as well, and while this may be in big part due to the different scientific fields involved, I think that adding a chapter, and dividing the chapters into two related groups, would have made the book more beneficial to readers.

Chapter one combines the lack-of-time problem with the paucity of fossil evidence for ape-like creature-to-human evolution problem.  Chapter three – the longest in the book – provides a detailed account of the deception (willful or not) by some scientists regarding the fossil line of evidence for human evolution, the data we have for that supposed line of evidence, and scientific criticisms of that data from top scientists in paleontology and related fields.  Chapter five is related to these in discussing “The Science of Adam and Eve,” while chapter four provides us information on junk DNA and chromosomal fusion.  For those who want to know more about this subject before reading the book, I present below concise information and quotes from chapters one (II) by Ann Gauger, three (I) by Casey Luskin, and five (III) by Ann Gauger.

I.  Hominin Phylogeny

If you try and talk to an ardent evolutionist, you are very likely going to come across this belief and attitude that the theory of evolution is written in stone, everything that one reads about it in textbooks and in mainstream media is true, that of course humans evolved from an ape-like ancestor, etc. etc.   But as is made abundantly clear in this book, many scientists publish studies in Nature and similar professional journals, who go against this “we know all” flow.  Human evolution is not at all clear-cut and the fossil record is severely lacking.  Many fossils that had been considered within the line of ancestral humans are now held in serious doubt.  Yet, these “negative” findings don’t make the news.  These study results don’t make it on the cover of Time.

I think a significant reason for the publication of this book stem from the false statements made by Professor Ronald Wetherington in 2009 to the Texas State Board of Education.  Either this guy is a liar or he is woefully uninformed of his own line of study.  He just couldn’t say enough about how the fossil record showing human evolution was a complete sequence, how it showed gradualistic change just like Darwin predicted, and how there are no gaps in the record – and those scientists who say otherwise are not telling the truth.  Well!  Sorry to say, but Professor Wetherington is the one not telling the truth, and persons such as these influence what gets taught in our schools and their words are parroted frequently and mindlessly.

Below are synopses of the fossils believed to be within the ancestral line to humans; many of these are actually not considered in line anymore by mainstream scientists in paleoanthropology or primate studies.  A chart showing the traditional, party-line view of human evolution is also shown below (from page 49).

Toumai Skull (Sahelanthropus tchadensis):  This species is represented by one skull with jaw fragments.  ~6.5 million years old.  Reported on in 2002, it is now considered by many to be a gorilla or ape or at least not in the human line.  If this skull is ancestral to humans, then australopithecines can’t be (pp 50-51).

Orrorin (Orrorin tugenensis):  Only a few bones are known of this species, and they do not include a skull or jaw.  ~ 6 million years old.  Even though little can be determined about this species’ way of moving, the conjecture by some that it may have walked upright was enough to put it in the human line.  Human evolutionary thinking had made bipedal walking a necessary condition for a fossil to be included in the human line.  However, we now know that this can no longer be a litmus test.  Why?  Because an ancient bipedal ape was discovered, Oreopithecus bambolii.  This creature is clearly an ape, it walked bipedally, and it lived ten million years ago.  We now know that some human-like physical features, that scientists considered unique to our line, developed in other species in parallel.  Nevertheless,if this species is found to be ancestral to humans, then australopithecines can’t be (pp 51-54).

Ardi (Ardipithecus ramidus):  Extremely reconstructed from very crushed and very friable and chalky bone fragments (skull and other parts).  ~4.4 million years old.  Even though the reconstruction of this fossil should have raised big doubts about any interpretations regarding it, it was in the news big time.  Even Science magazine joined in in the hype:

Science magazine named Ardi the “breakthrough of the year” for 2009, and officially introduced her with an article titled “A New Kind of Ancestor . . . (p 55).

After other scientists finally got to look at these fossil remains–which took over 15 years to “reconstruct”–claims of its bipedality were not affirmed.  Not only that, but some scientists hinted, and others said out-right, that Ardi was not a hominid, was not bipedal, and was closer to being an ape or orangutan (pp 54-57).

Australopithecines:  Because there are more Australopithecine fossils than any other, and because one in particular had become so popular–Lucy–it’s a bit hard to say only a little about this group of species.  In 2006 there was much hype over two canine teeth found of the species called Austropithecus anamensis.  I will say it again and allow the information to sink in:  there was much hype over only two canine teeth.  In any case, the author of the A. anamensis technical paper is worth quoting since he confirms Luskin’s contention:

Until recently, the origins of Australopithecus were obscured by a sparse fossil record . . . . The origin of Australopithecus, the genus widely interpreted as ancestral to Homo, is a central problem in human evolutionary studies.  Australopithecus species differ markedly from [both] extant African apes and candidate ancestral hominids . . . (p 58).

Let’s look at Lucy, an Australopithecus afarensis with purportedly 40% of it’s bones found.   First off, it’s not clear that all the bones of Lucy are actually hers.  The bones were highly spread out over a gully and one of its hillsides.  Many scientists no longer think Lucy walked upright like we do, or even at all, basically.  She very clearly has knuckle-walking hands, which no one denies but some try to excuse.  It is unlikely, from an evolution theory point of view, that she would retain these characteristics if she didn’t use them.  But to make a further argument about her mode of moving, the supposedly evolved form of Homo habilis retains some of these features 2 million years later.  Unused characteristics will not hang around that long in an evolved species.

Also, a whole slew of bodily features show that Lucy was ape- or chimp-like and was not at all adapted to running.  Australopithecine ear canals (for balance and locomotion) are not like humans but similar to apes.  They have grasping toes.  Professional studies and papers from 1975 and 2007 suggest that Australopithecines should no longer be considered part of the human line (pp 57-65).

Homo habilis:  ~1.9 million years ago.  The well regarded anthropologist Ian Tattersall of the American Museum of Natural History said this species is “a wastebasket taxon, little more than a convenient recipient for a motley assortment of hominin fossils.”  Besides this suggestive statement (suggestive of the quality of analyses that had gone on), Spoor et al. in Nature (1994) reported that the ear canal of this species was closer that of a baboon, and another study from 1991 “found that the skeleton of habilis was more similar to living apes than were other australopithecines like Lucy” (p 66).  Another scientist stated that habilis “‘displays much stronger similarities to African ape limb proportions’ than even Lucy” (p 67).  This species is therefore not considered to be in the human line (pp 65-67).

Standard Hominin chart Wells0001

[GAP]:  There are no transitional fossils between Australopithecus and Homo.  About 2 million years ago cranial capacity of the human line suddenly about doubled.

Homo and Australopithecus differ significantly in brain size, dental function, increased cranial buttressing, expanded body height, visual, and respiratory changes” and, the authors of the paper said “We, like many others, interpret the anatomical evidence to show that early H. sapiens was significantly and dramatically different from . . .  australopithecines in virtually every element of its skeleton and every remnant of its behavior (pp 67-68). . . .  The anatomy of the earliest H. sapiens sample indicates significant modifications of the ancestral genome and is not simply an extension of evolutionary trends in an earlier australopithecine lineage throughout the Pliocene.  In fact, its combination of features never appears earlier” (p 68; from Journal of Molecular Biology and Evolution 2000, emphasis mine).

The earliest fossils of Homo, Homo rudolfensis and Homo erectus, are separated from Australopithecus by a large, unbridged gap.  How can we explain this seeming saltation?  Not having any fossils that can serve as missing links, we have to fall back on the time-honored method of historical science, the construction of a historical narrative (pp 69-70; Ernst Mayr 2004, emphasis mine).

Homo erectus:  Extremely similar to modern humans – probably only a subspecies (so it was actually human). ~ 2 million years ago.  Cranial capacity is on average smaller, but still within the overall range of modern humans (which is incredibly varied).

Neanderthals (Homo neanderthalensis):  Very similar to modern humans and now known to be something like a subspecies of modern humans.  In fact, DNA studies show that many modern humans have Neanderthal DNA in them.  ~ .75 million years ago.  Cranial capacity on average was larger than modern humans.

II.  Evolution Time

There are no transitional fossils between Australopithecus and Homo (and some scientists, at least, no longer think Australopithecus should even  be in the homo line).  Ok.  But what time frame is there between these two species of Hominin?  About 1.5 to 2.o million years.  And how many traits arose or need to have changed?  About 16, at least, and many of these have to have occurred together – they won’t work apart from one another, or on their own they could even be harmful to the creature(s).

Based on experiments that test the rate of change at the molecular level, this number of changes within the known time frame would have been impossible.  Considering how slowly, relatively speaking, these hominins would reproduce, evolving even one homo feature from australopithecine would be basically impossible in the time frame we know exists between these species.  Gauger states:

You don’t have to take my word for it.  In 2007, Durrett and Schmidt estimated in the journal Genetics that for a single mutation to occur in a nucleotide-binding site and be fixed in a primate lineage would require a waiting time of six million years.  The same authors later [2008] estimated it would take 216 million years for the binding site to acquire two mutations, if the first mutation was neutral in its effect (pp 24-25).

III.  Are Only Two Human Parents Possible?

In Ann Gauger’s “The Science of Adam and Eve” (chapter five), she presents the history of research into the diversity of certain immune defense genes.  She does this since persons in the past used these genes, which have tremendous variety in our genomes and the genomes of our “cousin” species, to prove that humans could not have come from only two parents (like Adam and Eve).  The science involved is of course specific and complicated and I will not attempt to give am in-depth summary of it here.  What I will say is that an original study (published in 1995) found that chimps and humans shared 32 alleles of this gene (HLA-DRB1), and later study cut that down to seven and showed a whole new complication that was a mystery (different portions of the same gene yielded wildly different results).

The results were mysterious because it turns out that even though the gene has 100s of allele variations (there are a number of HLA genes, and each has hundreds of alleles), most are not recombined and therefore are known as haplotypes.  These haplotypes are inherited in blocks, and there are very few of these in humans – five, in fact.  Three are very ancient and two are, well, not as ancient (~30 mya or more, and ~ 5 mya, based on current evolutionary assumptions), and one is not shared with chimps.  Each person can carry two different alleles of the HLA gene studied.  So it is now known to be in the realm of possibility that we all came from two parents only, each carrying two different HLA alleles.

The later study, and others, provided data that may also force a change in neo-Darwinian thinking.  This newer data show that we share genes with other species that are not common ancestors.  We have some gene sequences that are more closely related to gorillas than chimps, and we have sequences resembling those from macaques – animals that are not in our hominid group.  What does this data do to the whole concept of common descent?  (pp 103 – 121).

*      *      *

So what we end up with is a hominin family tree that, if a number of scientific studies and their conclusions are to be followed (the papers being in the major journals in their fields), would be gutted.  Continuous, gradual, evolutionary change in the hominin line?  No, not at all.  We also have the science of nucleotide-binding mutations indicating that there is no possibility, given the relatively short time frame, that any fossil currently thought to represent an ancestor in the human line could have evolved into a human.  Please read the book for more detailed information, but for checking out the references as well.