Biological Fossils Human Evolution


Cladistic analysis is a popular method for reconstructing evolutionary relationships on the human lineage. However, it has limitations and hidden assumptions which researchers have adopted that are logically untenable and introduce considerable error. Examples such as bigger skulls mean bigger brains and higher intelligence (bigger body size is better), or jaw bone differences are better, all suffer from logical weaknesses of circularity. These lead directly to bias.”-5 (Paraphrased)

“Most hominid fossils, even though they serve as a basis for endless speculation and elaborate storytelling, are fragments of jaws and scraps of skulls.” 

“The Panda’s Thumb: More reflections in Natural History”, Gould, Stephen Jay; 1980 p. 126

What are anatomical similarities?

Anatomical similarities are similar physical traits among different organisms.  Anatomical similarities primarily focus on two forms of investigation: form and function.  A common comparison for form includes similar (homologous) appendages like the five fingers of humans compared to bird wings or even whale flippers.  In human evolution, such comparisons extend into the shape of skulls and jaws in ape and human fossils.  A characteristic of function might be feathers, as used for flight in many birds.  Exceptions to these categorizations are uncommon, opening the entire proposition to severe criticism (even among its strongest proponents). 

Some round pegs and square holes?

As just one of many exceptions made to such rules, like a round peg being hammered through a square hole, including the theory that modern birds are direct descendants of dinosaurs, many anatomical dissimilarities are ignored to make this connection, such as birds being warm-blooded with feathers while dinosaurs are cold-blooded land lizards.  Nevertheless, dinosaurs and birds are categorized together in cladistical categorizations.   

“Cladistics is a method used for the classification of animals, insects, and plants (taxa) according to the proportion of measurable characteristics that they have in common (anatomical or genetic similarity) that is used to infer shared characteristics of supposed ancestral groups inferring that all such members have the same ancestors.”

Cladistics rests upon three assumptions: (1) living things are related by descent from a common ancestor; (2) speciation occurs by splits of one species into two; and (3) traits change enough over time to be measurable.  The best tree topologies have the fewest trait reversals and independent character changes. -1

What is compared in cladistics? 

Cladistic analysis is a popular inference for constructing evolutionary topologies (trees or webs) based on (I) living organisms and (II) fossils. Traits considered for each include (1) behavior similarities; (2) anatomical or physiological similarities; and (3) genetic sequence similarities.   Behavioral and genetic similarities are not considered here in this article.  More on the weaknesses of genetic similarities within fossil forms here. More on the general weaknesses of genetic similarity comparisons here.

This article shall focus on considering how anatomical or physiological similarities between fossils and extant life forms might provide evidence to substantiate the high claims of universal common ancestry of all life, specifically here regarding human evolution.

“Similarity by itself says nothing about what mechanisms are responsible for the apparent relatedness…depends on one very big but unproven assumption–that any similarities found are due to descent from a common ancestor.”-3 Bold is mine.

What are compared for anatomical similarities in human evolution?

The similarity of various shapes, lengths, and sizes between apes, monkeys, and humans is compared to identify the delicate clues that might indicate humans’ gradual descent from animals.  Paleoanthropologists study fossils and bones of skulls, jaws, teeth, legs, arms, hands, feet, toes, etc.  While researchers focus on similarities, they often must ignore many major differences between anatomical structures.  For example, other anatomical structures such as shoulders, rib cages, pelvises, and hips are often ignored, especially when the evidence shows no apparent or measurable transition.  

No one doubts the similarity human beings have with primates.  We have similarities like two legs, two arms, ten fingers and ten toes, similar skull shapes, etc.  We likewise observe anatomical similarity throughout many living organisms, such as having five digits.  However, from a purely biological perspective, these differences persist throughout time. 

Evidence consists of bone fragments.

The subtleties that imply a gradual transformation often comprise a few bone fragments or teeth.  Most all the fossil specimens that compose the elegant charts on the internet can be contained within the space of one shoebox. 

“Typical hominin fossils consist literally of mere bone fragments…the fossil evidence for human evolution remains fragmentary…the primary scientific evidence (relied upon by paleoanthropologists) to construct man’s evolutionary history is a pitifully small array of bones…”


All too often, any significant anatomical appendages that might help prove these transformative assumptions are missing, including jaws, femurs, finger bones, toe bones, pelvises, etc.  This was the case with the famous (now debunked) walking chimpanzee named Lucy. 

Lucy was constructed to illustrate bipedalism.

“Lucy’s” bones fit together with ape proportions– the bipedal (upright) walk is superimposed upon missing evidence from the arm bones and leg bones.  Chimpanzees have longer arms for swinging in the trees and shorter legs as knuckle walkers.  The specimens within “Lucy” have the middle sections of both the legs and arms missing.  Therefore, the entire claim of bipedalism is merely an assumption that the arm bones were shorter and the leg bones were longer.-4

From illustration above:

  1. Lucy’s arm bones are broken, and pieces are missing, so the original length is unclear. If you compare the taper of the bones, the middle section appears to be missing. This could indicate that she had long, ape-like arms (seen above). Evolutionists do not allow much space for missing pieces between the bones, giving Lucy shorter human-like arms.
  2. Lucy’s leg bones are also fragmented, so there is some leeway in estimating the original length. The bones would fit together fine with short ape-like legs (seen above). Evolutionists have added as much as half a foot (15 cm) into the gaps, producing long, human-like legs.

Missing evidence can transform ape feet into human.

University of Chicago anatomist E. Oxnard observed several reconstructed foot bone assemblies supposed to belong to pre-human cousins (of the Australopithecus)

“A series of associated foot bones has been reconstructed into a form closely resembling the human foot today although a similarly incomplete foot of a a chimpanzee may also be reconstructed in such a manner.”

Chicago anatomist E. Oxnard

Flesh reconstructions are highly dubious

“Flesh reconstructions are also highly subjective….attempt to diminish intellectual abilities or humans…(while giving) ape-like reconstructions gleams of human-like intelligence and emotion in its eyes–a tactic common in illustrated books on human origins.”  -3 (p. 46-47-bold is mine)

“These aren’t portraits. (They are) a broad idea of how someone would have looked…But what brings a lots of character to a person, is the fullness of the lips, the shape of the nostrils, the shape of the tip of the nose, the folds of the eyes – and you can’t know this.”

Natural History Museum.

University of North Carolina anthropologist Jonathan Marks warns against this when lamenting the “fallacies” or “humanizing apes and ape-ifying humans”  Jonathan Marks, “What it means to be 98% Chimpanzee: Apes, People, and their genes”, 2003. Bold is mine.

Harvard University Earnest Hooton noted, “Alleged restorations of ancient types of man have little scientific value and are likely only to mislead the public.” Earnest Albert Hooton, “Up From The Ape,” Revised ed. 1946, p 329. Bold is mine.

Human and Ape anatomy is functionally different.

“Chimps are suited for life in the trees.  Humans are suited to live on the ground, walking and running.  The anatomical changes needed to move from tree-dwelling to complete terrestrial life are many….requires a new spine, a different shape and tilt of the pelvis, and legs that angle in from the hips…we need knees, feet, and toes designed for upright walking, and a skull that sits on top of the spine…jaws and muscle attachments must be shifted, face flattened, sinuses (moved), eye sockets located in different places…humans have significantly different shoulders, rib cages, spines, pelvises, hips, legs, arms, hands, and feet…”-3 (p. 21-22)

“…the plausibility (that life forms evolved from one another) can’t be counted on just because they end with something similar to what they started with.” (p. 35)

“Hominin fossils generally fall into one of two groups: ape-like species and human-like species, with large, unabridged gap between them.” {p. 45)

“…the fossil evidence for human evolution remains fragmentary, hard to decipher, and hotly debated.” (p. 45)

Skull size equates to intelligence?

Brain size is not a good indicator of intelligence. 

Human males have a skull range of 1150-1600 ml, while females have a range of 1050-1400. The average human skull combining both sexes is about 1400 ml.-6. Does this mean that females are less intelligent than males?  Surely not! Many IQ tests have repeatedly confirmed this reality. Certainly, female human beings are not less evolved than males.

How about individuals affected by dwarfism? Are they less intelligent than average-sized people because they have markedly smaller brain matter?  No–of course not. 

“Dwarfism does not affect intellectual abilities.”,like%20their%20average%2Dsize%20peers.

“Almost all people with disproportionate dwarfism have normal intellectual capacities”.

Brain size evolution?

Neanderthal human beings had larger brains then modern humans!

“However, there is some “evolutionary irony” that in the past 10,000 years our brains shrunk. Why? Because Neanderthals had bigger brains than modern humans.”

Many of these premises surrounding anatomy and skull sizes are subjectively applied by biased researchers to relate the tale they wish to tell ultimately. Skull size, as an indicator of intelligence in humans, is a pseudo-science.  In fact, it seems that brain size is not a strong indicator of intelligence across all mammals and even much of life on Earth. Even bird brains are intelligent! Crows are considered among the most intelligent animals, with a brain size of merely a human thumb.-7

“A crow’s brain is the size of a human thumb, huge relative to its body, putting their intelligence on par with primates and allowing them to solve complex problems.”-8 Bold is mine.

“Human brains vary considerably in size across adults, with males having slightly larger brains than females. It is hard to pinpoint what makes the human brain exceptional among mammals—neither brain size, relative brain size nor number of neurons is unique to humans.” › Jan 1, 2016. Bold is mine.


Chart after chart, illustration after illustration, as found on the internet, line up skulls and appendages from small to large as if to indicate that somehow blind evolution keeps building life forms bigger, better, more accessory rich, and (of course) smarter.  This assumption permeates throughout human evolution. However, we do not have any fossil evidence to support this massive claim. 

“The fossil record provides ape-like australopithecines and human-like Homo, but not the fossils documenting the transition between them.”

-3 (p. 69) 

In other words, the missing link between apes and human beings is still missing.  Therefore, any claims of fossil evidence providing transitional fossil evidence are reduced to mere inferences.  Inferences are made as a form of circular logic or a begging-the-question logical fallacy.  As we found earlier, the first assumption of cladistical categorizations of life starts with the conviction that all life has a universal common ancestor.   The anatomical similarity is proposed as evidence to defend that claim, such as humans descended from apes.  Clearly, this is begging the question because how can the effect be proven by the cause based on the cause being proven by the effect?  For anatomical similarity to even apply as evidence for a common ancestor, we must begin by assuming that it is true.  In the end, all we have to hold onto are assumptions based on assumptions.       

Cladistic analysis is a popular method for reconstructing evolutionary relationships in the human lineage. However, it has limitations and hidden assumptions often not considered by palaeoanthropologists. Some researchers who are opposed to its use regard cladistics as the preferred method for taxonomic “splitters” and claim it has led to a revitalization of typology. Typology remains a part of human evolutionary studies, regardless of the acceptance or use of cladistics. The assumption/preference for “splitting” over “lumping” in cladistics (alpha) taxonomy and the general failure to evaluate (post-hoc) such taxonomies have served to reinforce this assertion. Researchers have also adopted a number of practices that are logically untenable or introduce considerable error. The evolutionary trend of human encephalisation (bigger brains mean more intelligence fallacy), apparently isometric with body size (bigger is more evolved fallacy), and concurrent reduction in the gut (certain digestion function is presumed to superior) and masticatory apparatus (jaw bone differences–the evolution of humans has not unraveled the basic functional relationships within the masticatory apparatus that characterize most primates) , suggests continuous cladistic characters are biased by problems of body size. The method suffers a logical weakness, or circularity, leading to bias when characters with multiple states are used. Coding of such characters can only be done using prior criteria, and this is usually done using an existing phylogenetic scheme. Another problem with coding character states is the handling of variation within species. While this form of variation is usually ignored by palaeoanthropologists, when characters are recognized as varying, their treatment as a separate state adds considerable error to cladograms. The genetic proximity of humans, chimpanzees and gorillas has important implications for cladistic analyses. It is argued that chimpanzees and gorillas should be treated as ingroup taxa and an alternative outgroup such as orangutans should be used, or an (hypothetical) ancestral body plan developed. Making chimpanzees and gorillas ingroup taxa would considerably enhance the biological utility of anthropological cladograms. All published human cladograms fail to meet standard quality criteria indicating that none of them may be considered reliable. The continuing uncertainty over the number and composition of fossil human species is the largest single source of error for cladistics and human phylogenetic reconstruction.”-5

Curnoe D. Problems with the use of cladistic analysis in palaeoanthropology. Homo. 2003;53(3):225-34. doi: 10.1078/0018-442x-00048. PMID: 12733396. Bold is mine.


1-  LibreTexts Biology 12:2 Determining Evolutionary Relationships

2-  Citations for illustrations:  Young, N. M., Wagner, G. P., & Hallgrímsson, B.(2010).Development and the evolvability of human limbs.Proceedings of the National Academy of Sciences, 107(8), 3400-3405.

3-“Science & Human Origins” Gauger, Ann; Axe, Douglas; and Luskin, Casey 2012.

4-“These Bones Were Made for Swingin’” Mar 2017;

5- Curnoe D. Problems with the use of cladistic analysis in palaeoanthropology. Homo. 2003;53(3):225-34. doi: 10.1078/0018-442x-00048. PMID: 12733396.,using%20an%20existing%20phylogenetic%20scheme.

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