Making Stone Tools / A Non-verbal Process

A super group of videos…

Not a single word is needed to do this or to teach someone else to do this. The “tips” at the end would be demonstrated during the process. Children would see tools and other objects made day in and day out and would naturally copy their elders.

Archaeologists go on and on about how it takes “advanced cognitive skills” (like those needed to push around a shopping cart and swipe a credit card) to create stone tools. I have yet to hear a single researcher mention visual thinking. You can babble at a pile of stones, or another human, all day long, but all that yack-yacking will not produce one stone tool. The earliest stone tools are millions of years old; sophisticated flaked tools (Acheulean) were invented by Homo erectus, not Homo sapiens. Some research indicates that ‘language’ structure had its beginnings in sign language and not in vocalization. Pre and early humans were visual observers,  inventors and communicators – and not at all like modern social humans, who are a very recent “neotenic” variation of Homo sapiens.

All it takes is A FEW adept individuals to preserve techniques and to pass on skills. If a group were lucky, one “genius” might come up with improvements and refinements so that technical advancement could occur – which would probably be forgotten and reinvented many times. And critically, resources in one’s environment dictated solutions: nomadism provided exposure to new raw materials and new people, so “itchy feet” were likely more advantageous than staying in one place too long.



New Experience / Academic insanity meltdown

I’m feeling physically ill this morning; stayed up late subjecting myself to the content of  a “scientific” paper that is the worst pile of crap I’ve ever encountered – published in a serious British journal. The subject: Social evolution of humans. The “line of thinking” is so outrageous, so intellectually offensive, that I would call it pornographic: intellectual porn.

A criminal use of the human brain.

I intended to expose this paper, but it had such a disturbing effect that I couldn’t continue with a critique. My point is, that I’ve discovered this “feeling” in myself of “insult by intellectual attack” and I have no word for it. (I bet the Germans do)Something like a meltdown; an attack on sanity delivered by “thought pollution” and not by sensory overload. And I don’t mean a personal attack, but that the assumptions and assertions made and represented as “scientific” work were published by a top journal, as if no one noticed the absurdities.

I even thought momentarily that the paper was an intentional monstrosity, “planted” to test the (corrupt?) review process of some science publishers…so went looking for more papers using search words that were “ungoof- upable” even by google. OMG! The paper was not a “fluke”.

I did encounter a review of the paper and its ideas by a scientist in the same field and it was “politely” scathing – about as close to a tirade as a review can get. It should have made me feel better. It didn’t, because the paper’s writers are established “prestigious” academics, not “ancient alien” conspiracy crackpots – but crackpots within the sciences.

Am I overreacting? I would say not, because this paper served as the “trigger” for the cumulative response to a lifetime of encounters with “nonsense” as the prevailing trend in modern thought. That is, it is the difference between “studying” earthquakes and being in the zone of destruction when the earth “slips” violently – and suddenly, physically, viscerally one experiences the full meaning of danger.

It’s a “Bhuddist” moment for me.



Neanderthals kept H. sapiens out of Europe for 40,000 years

Neanderthal: general extent of occupation.

The discovery of a hoard of ancient human teeth in a Chinese cave has forced scientists to reconsider our species’ relations with our closest evolutionary cousins, the Neanderthals. The find, revealed in the science journal Nature, shows modern humans must have left their African homeland and reached southern China more than 80,000 years ago.

This unexpectedly early date contrasts with our ancestors’ far more recent arrival in Europe – about 45,000 years ago – and suggests Homo sapiens was prevented, for some reason, from moving there for tens of thousands of years. Anthropologist María Martinón-Torres, from University College London – a member of the team that made the discovery – is confident of the reason. She blames the Neanderthals.

Homo sapiens evolved in Africa and emerged from the continent about 100,000 years ago and swept eastward with little apparent resistance from other hominid species they encountered. But when they headed north, they reached the Levant and met the Neanderthals at the southern edge of their European domain. And there they stopped our spread. Essentially Europe was too small for the both of us.”

Neanderthals were experienced hunters and gifted foragers, and had controlled Europe for hundreds of thousands of years. They were therefore able to keep us at the edge of Europe for 40,000 years, added Martinón-Torres. “It was not a matter of physical confrontation, however. It was a matter of who was best able to exploit resources. They had much more experience of the harsher, colder conditions that existed in Europe. I think we have underestimated them. They were not grunting, ignorant cavemen. They were our equals.”

The discovery of the teeth – 47 found at Fuyan cave in Daoxian, in southern China – was made by a team led by Wu Liu of the Chinese Academy of Sciences, Beijing. The teeth were beneath rocks over which stalagmites had grown. Dating techniques indicate the stalagmites are at least 80,000 years old. And so everything below that layer must be older. (Teeth are made of dentine and enamel and the latter is the body’s hardest tissue. As a result, teeth are often preserved at prehistoric sites while other body parts decay and leave no trace.) In fact, the teeth could be up to 125,000 years old, researchers suggest. Nevertheless they closely resemble those of modern Europeans. “The Fuyan teeth indicate that modern humans were present in southern China between 30,000 to 60,000 years earlier than in the eastern Mediterranean and Europe,” states archaeologist Robin Dennell in a commentary article about the find in Nature.

The difference in timescale is remarkable. Modern humans were thought to have left their African homeland about 60,000 to 70,000 years ago, eventually reaching Europe about 45,000 years ago, the earliest date that scientists have established for the presence of Homo sapiens there. It then took a further 15,000 to 25,000 years to complete our conquest of Europe. However, the new study suggests the real figure is far higher and modern humans had to wait between 40,000 and 50,000 years before they got into Europe.

In contrast to our progress northward, modern humanity’s progress eastward was unexpectedly rapid. However, not every scientist blames the Neanderthals for blocking our progress in Europe. “One possibility is that an early dispersal headed eastwards through Arabia away from Europe and that the colonisation of Europe through the Levant occurred via a later dispersal,” said Professor Chris Stringer, of the Natural History Museum, London.

“In addition, the climate in Europe was relatively cold and inhospitable then,” he said. “We were not properly adapted to conditions and couldn’t get a toehold – and, of course, the Neanderthals were there already.”

However, when modern humans did arrive in Europe, they made remarkable progress. Within a few thousand years, they had settled across the continent while the Neanderthals had disappeared. As to the causes for this rapid extinction, researchers point to the harsh climate Neanderthals had endured in Europe for the previous 200,000 years, when the continent was swept by ice ages and intense cold. Conditions eventually took their toll and numbers of Neanderthals dwindled. Tribes got smaller and smaller and their genetic diversity was compromised. (Novel-writing)

“Essentially, Neanderthals were eventually left in a genetically exhausted state,” said Martinón-Torres. “When we did get into Europe there were hardly any of them left. The rest went quickly after that.”


Science of Brow Ridge / Primate Torus CARTA

Morphology of the Brow Ridge

Not to be confused with the backward baseball cap tan

from CARTA /

Considerable variation exists between hominoid species in the morphology of the supraorbital region. Gorillas and chimpanzees (and most fossil hominins) possess a prominent supraorbital torus, or brow ridge, presenting as a continuous projecting ridge above the orbits and nose (although continuous, the torus is anatomically divisible into three regions: laterally positioned supraorbital trigones, medially positioned supercillary arches, and a midline glabellar prominence). In these species with prominent brow ridges, a supratoral sulcus is generally present as a shallow groove just posterior to the torus. (Modern) Humans and orangutans lack prominent brow ridges. Brow ridges may develop as an architectural or biomechanical by-product of hafting a prognathic (projecting) face onto the low frontal bone characteristic of apes and earlier humans, such that the lack of a brow ridge in modern humans is a consequence of their having an orthognathic (vertical) face and vertical frontal (high forehead). Orangutans possess a supraorbital rim (a thin, non-projecting ridge across the orbits) rather than a torus, which may be a function of the airorynchy (backwards rotation of the face towards the neurocranium) that characterizes these apes.
Seemingly thousands of scientific papers, popular musings and other articles focus on TESTOSTERONE / low-high, male-female and the implications in morphology, human variation, attractiveness, social status, etc. So I won’t go into all that here.
But I did notice something about primates, while looking at images under “brow ridge” and related searches.
Nature is “in love with” built-in architectural protection for eyes:
And often combines this feature with other defensive-offensive skull features.
In most primates, male and female skulls have a “torus” that reinforces the eye sockets and provides protection and sun shade – glare reduction for the eyes. 
The vegetarian, mostly docile gorilla, has a significant brow that actually makes it difficult to see its eyes…
which are visible from a certain head position. We might call this the primate dominance gaze. Not overtly aggressive, but perfectly clear as a statement of power.
And, in fact, this “gaze” has been utilized by Hollywood to great effect: it is a standard publicity pose for leading male actors.

Rudolph Valentino

And it is effective in male dominance: Eyes shaded to “hide” information as to one’s mental-emotional state from a possible opponent…
 which increases the visual effectiveness of the true dominance stare. 
which is a lot like the pan-species “predator” stare:

which in modern western cultures is interpreted to be a “sociopath-psychopath” stare.
So be careful…
Military helmets are often designed to amplify the brow ridge effect, especially if it’s missing. And how can we ignore the ultra-male Klingons?
Sunglasses might be considered to be an artificial enhancement or prosthetic “brow ridge”.

The bizarre nightmare of “periods” / An Evo Biologist explains…

QUORA Question:

What is the evolutionary benefit or purpose of having periods?

(Thanks to a tip from Humanity’s Darker Side) –

I’m so glad you asked. Seriously. The answer to this question is one of the most illuminating and disturbing stories in human evolutionary biology, and almost nobody knows about it. And so, O my friends, gather close, and hear the extraordinary tale of:


Contrary to popular belief, most mammals do not menstruate. In fact, it’s a feature exclusive to the higher primates and certain bats*. What’s more, modern women menstruate vastly more than any other animal. And it’s bloody stupid (sorry). A shameful waste of nutrients, disabling, and a dead giveaway to any nearby predators. To understand why we do it, you must first understand that you have been lied to, throughout your life, about the most intimate relationship you will ever experience: the mother-fetus bond.

“What this means is that the growing fetus now has direct, unrestricted access to its mother’s blood supply. It can manufacture hormones and use them to manipulate her. It can, for instance, increase her blood sugar, dilate her arteries, and inflate her blood pressure to provide itself with more nutrients. And it does. Some fetal cells find their way through the placenta and into the mother’s bloodstream. They will grow in her blood and organs, and even in her brain, for the rest of her life, making her a genetic chimera**.”

Chimera, in genetics, an organism or tissue that contains at least two different sets of DNA…

Much, much more information:  


H. Erectus Potpourri / Videos + paper

Homo erectus: Why can’t I get no respect!

Brain size? Some weaseling here! Late erectus up to 1250cc. Modern human range is 950cc – 1500cc.

It’s also “cheating” to compare H. erectus skulls to contemporary homo sapiens skulls, as if archaic Homo sapiens didn’t have a whopping big brow ridge and robust skull!

The fossilized remains of Homo sapiens idaltu were discovered in 1997 by Tim White at Herto Bouri near the Middle Awash site of Ethiopia’s Afar Triangle. Dating took place by the radioisotope method which analysed the volcanic layers containing the 3 cranial fossils [White 2003].

 The morphology of the skulls display archaic features not found in the later Homo sapiens, but are still seen as the direct ancestors of modern Homo sapiens sapiens.  The remains discovered at Herto Bouri have been named ‘Herto Man’. Experts claim the finds are complete enough to be identified as early modern humans, since they show the characteristic globular shape of the braincase and the facial features of our species. However, both the adult skulls are huge and robust, and also show resemblances to more primitive African skulls.
Homo sapiens by Kennis & Kennis / Based off of Jebel Irhoud 1, one of the oldest remains of anatomically modern humans, an adult male at 160,000 years old, from Jebel Irhoud cave in Morocco:


PMID: 18191986 DOI: 10.1016/j.jhevol.2007.11.003

Taxonomic implications of cranial shape variation in Homo erectus.

Baab KL1., Department of Anatomical Sciences, Stony Brook University


The taxonomic status of Homo erectus sensu lato has been a source of debate since the early 1980s, when a series of publications suggested that the early African fossils may represent a separate species, H. ergaster. To gain further resolution regarding this debate, 3D geometric morphometric data were used to quantify overall shape variation in the cranial vault within H. erectus using a new metric, the sum of squared pairwise Procrustes distances (SSD). Bootstrapping methods were used to compare the H. erectus SSD to a broad range of human and nonhuman primate samples in order to ascertain whether variation in H. erectus most clearly resembles that seen in one or more species. The reference taxa included relevant phylogenetic, ecological, and temporal analogs including humans, apes, and both extant and extinct papionin monkeys. The mean cranial shapes of different temporogeographic subsets of H. erectus fossils were then tested for significance using exact randomization tests and compared to the distances between regional groups of modern humans and subspecies/species of the ape and papionin monkey taxa. To gauge the influence of sexual dimorphism on levels of variation, comparisons were also made between the mean cranial shapes of single-sex samples for the reference taxa. Results indicate that variation in H. erectus is most comparable to single species of papionin monkeys and the genus Pan, which included two species. However, H. erectus encompasses a limited range of variation given its extensive geographic and temporal range, leading to the conclusion that only one species should be recognized. In addition, there are significant differences between the African/Georgian and Asian H. erectus samples, but not between H. ergaster (Georgia+Africa, excluding OH 9 and Daka) and H. erectus sensu stricto. This finding is in line with expectations for intraspecific variation in a long-lived species with a wide, but probably discontinuous, geographic distribution.

PMID: 18191986 DOI: 10.1016/j.jhevol.2007.11.003

New! DNA / Common ancestor Neanderthal – Denisovan – “Us”

Schematic representation of the evolutionary scenario for mitochondrial and nuclear DNA in archaic and modern humans. Neanderthal mitochondrial DNA recovered in this study suggests an intermediate migration out of Africa before 220,000 years ago. Credit: Annette Günzel, © Max Planck Institute for the Science of Human History

Read more at:


In Neanderthal DNA, Signs of a Mysterious Human Migration

by Carl Zimmer / New York Times / MATTER JULY 4, 2017

With fossils and DNA, scientists are piecing together a picture of humanity’s beginnings, an origin story with more twists than anything you would find at the movie theater.

The expert consensus now is that Homo sapiens evolved at least 300,000 years ago in Africa. Only much later — roughly 70,000 years ago — did a small group of Africans establish themselves on other continents, giving rise to other populations of people today.

To Johannes Krause, the director of the Max Planck Institute for Human History in Germany, that gap seems peculiar. “Why did people not leave Africa before?” he asked in an interview. After all, he observed, the continent is physically linked to the Near East. “You could have just walked out.”

In a study published Tuesday in Nature Communications, Dr. Krause and his colleagues report that Africans did indeed walk out — over 270,000 years ago.

Based on newly discovered DNA in fossils, the researchers conclude that a wave of early Homo sapiens, or close relatives of our species, made their way from Africa to Europe. There, they interbred with Neanderthals.

Then the ancient African migrants disappeared. But some of their DNA endured in later generations of Neanderthals.

“This is now a comprehensive picture,” Dr. Krause said. “It brings everything together.”

Since the 1800s, paleontologists have struggled to understand how Neanderthals are related to us. Fossils show that they were anatomically distinct, with a heavy brow, a stout body and a number of subtler features that we lack. The oldest bones of Neanderthal-like individuals, found in a Spanish cave called Sima de los Huesos, date back 430,000 years. More recent Neanderthal remains, dating to about 100,000 years ago, can be found across Europe and all the way to southern Siberia.

Then, 40,000 years ago, Neanderthals vanish from the fossil record.

As a graduate student in the mid-2000s, Dr. Krause traveled to museums to drill bits of bone from Neanderthal fossils. In some of them, he and his colleagues managed to find fragments of DNA that they could study.

Scientists who study ancient genes search for two kinds of genetic material. The vast majority of our genes are in a pouch in each cell called the nucleus. We inherit so-called nuclear DNA from both parents. But we also carry a small amount of DNA in the fuel-generating factories of our cells, called mitochondria. We inherit mitochondrial DNA only from our mothers, because a father’s sperm destroys its own mitochondrial DNA during fertilization.

Years ago, Dr. Krause and his colleagues started their search for ancient Neanderthal genes in a fossil by looking for mitochondrial DNA. After discovering mitochondrial DNA in some fossils, they later managed to find nuclear DNA. The genes held some surprises. For example, bits of DNA in living people of non-African ancestry come from Neanderthals. When modern humans expanded out of Africa, they seem to have interbred several times with Neanderthals.

Those children became part of human society, passing on their genes.

But a finger bone and a tooth from a Siberian cave called Denisova left Dr. Krause and his colleagues with a baffling puzzle. Inside those fossils, the scientists found sequences of mitochondrial DNA that were not human or Neanderthal, but something else — a distant branch of the family tree. The Neanderthal mitochondrial DNA was much closer to our own.

Later, the researchers managed to recover the nuclear DNA from the Denisovan finger bone, which showed Denisovans and Neanderthals were more closely related to each other.

As scientists found ancient DNA in more fossils, our history has come into sharper focus. Scientists now estimate that the common ancestor of modern humans, Neanderthals and Denisovans, lived between 765,000 and 550,000 years ago.

About 445,000 to 473,000 years ago, that common ancestor’s descendants split into two lineages. One eventually led to modern humans, while the other led to Neanderthals and Denisovans.

After years of investigation, however, Dr. Krause still did not understand why the nuclear DNA and mitochondrial DNA of Neanderthals seemed to have different histories. The mystery only deepened in 2013. Another team of researchers retrieved mitochondrial DNA from a Neanderthal-like fossil at Sima de los Huesos, dating back 430,000 years.

The researchers had expected the DNA to resemble that of later Neanderthals in Europe. Instead, the mitochondrial DNA looked like it belonged to Denisovans — even though the Denisova cave was 4,000 miles away in Siberia. Last year, the researchers announced they had gathered a small fraction of the nuclear DNA from the same Sima de los Huesos fossil. That genetic material looked like it belonged to a Neanderthal, not a Denisovan.

Dr. Krause and his colleagues have now discovered new Neanderthal DNA that they believe can solve the mystery of this genetic mismatch. In 2013, one of Dr. Krause’s graduate students, Cosimo Posth, examined a Neanderthal fossil from a German cave called Hohlenstein-Stadel. He was able to reconstruct all of its mitochondrial DNA.

Dr. Posth estimated that the Neanderthal fossil was 120,000 years old and, more important, that it belonged to a branch of the Neanderthal family tree with a long history. He and his colleagues determined that all known Neanderthals inherited their mitochondrial DNA from an ancestor who lived 270,000 years ago.

All the data pointed to a sequence of events that could solve the puzzle that had bedeviled Dr. Krause for so long. The common ancestors of Neanderthals and Denisovans spread across Europe and Asia over half a million years ago. Gradually the eastern and western populations parted ways, genetically speaking. In the east, they became Denisovans. In the west, they became Neanderthals.

Over many generations, most of that new DNA disappeared. But the mitochondrial DNA survived, passed down from mothers to their children. In fact, eventually all the Neanderthals inherited it, for some reason discarding the mitochondrial DNA that the species once had.

Dr. Posth said it was possible that early members of our own species moved from North Africa into Europe. Supporting this idea was the discovery reported last month of fossils of Homo sapiens in Morocco dating back 300,000 years. But Dr. Posth said it was too soon to rule out another possibility: that these migrants belonged to another species in Africa closely related to us that scientists have yet to document.

“I feel uncomfortable to give a name to these humans,” Dr. Posth said.

The new study raises a host of tantalizing implications about human history.

It is not possible to know just how many times these early Africans interbred with Neanderthals. But somewhere in prehistory, at least one female human from Africa must have carried the child of a male Neanderthal.

“Now you have this hybrid child, which is probably pretty unusual-looking,” Dr. Siepel said. “One way or another, this hybrid individual was absorbed into Neanderthal society.”

Dr. Siepel warned that the hypothesis hinges on the new DNA found in the Hohlenstein-Stadel fossil. Dr. Krause and his colleagues are now trying to retrieve nuclear DNA from the fossil.

The research at Sima de los Huesos shows just how far back in time scientists can now search for genes. The most revealing DNA might come from the mountains of Morocco. There, scientists may be able to find genes from the earliest Homo sapiens, which they can then compare to Neanderthals’.

“These are things that I never thought possible five years ago,” Dr. Krause said.

Follow Carl Zimmer on Twitter @carlzimmer









Evolutionary History of Female Homo Sapiens

Am I joking? No.

There’s not much material on this topic, because “evolution” and “male” have always been accepted as encompassing “human evolution”. Evolution scientists and amateurs alike still argue over “manly things” as determining what characterizes “being human”. Female Homo sapiens and her ancestors – female apes and archaic homo; Homo sapiens (early and late,) have been all but ignored, hanging around in the mists of time doing nothing important. Which is ironic, since “evolution” cannot occur without the production of successful offspring, which also must reproduce, etc. Sexual reproduction requires male and female. How difficult is that to grasp?

Sadly, topics which might become less “mysterious” in human evolution require understanding the evolution of the female body and brain, and in particular, the literal “growing” of new humans within the female body, and their introduction into the environment. But, reproduction is all but ignored by the “definers of species characteristics and boundaries”. The body of myth, mystery and rumor that surround the process of reproduction today, and in an evolutionary context, is ASTOUNDING.

Much is made of “difficult human birth” but curiosity as to “Why is this so?” generally begins with religious prejudice (God makes women suffer and die in childbirth because women are evil, inferior and weak) and ends in the scientific conclusion that “big-brain=big head” makes delivery difficult. (Gee whiz! Males don’t have to experience this phenomenon, so who cares?)

Gynecologists and other “specialists in human reproduction” care. It’s their job, but that doesn’t mean that there is much curiosity as to the evolution of human childbirth. The literature is jam-packed with the excruciating details of the “problem” of difficult childbirth and how to “deal with” the situation, but not much more than passing concern is directed to “the big picture” of human reproduction as a product of evolutionary process.

Modern women, especially in the U.S., are consumed by the pressure to “have children as proof of their femininity” and become obsessed by the “acquisition” of children in a social context. The changes that have taken place in society, which “allow” women to pursue lifestyles other than “domestic goddess” have produced a backlash, which is in essence a punishment. If women want a “career” they must compensate by also being a “super mother” – a demand something like having to tie one hand behind the back in a boxing match. Any difficulty in conception is taken personally – and any and all “fixes” by medical and technical intervention are required. This fear of bio-social incompetence extends throughout pregnancy, delivery and infant care, and indeed for the life of the child, until “Mom” dies. And in many families, Mom is still responsible for guiding her children’s behavior, but from the afterlife!

It is also astounding how little women know about their own bodies.

Where to start? Who were those female critters that are considered to be enough like us to be species that “led to” us, Homo sapiens. The important characteristic is bipedalism – standing and walking on two legs.

The following is highly simplified and covers a huge span of time – 4+ million years to the present. Needless to say, there is actually very little known that is “definite” due to the scarcity of fossil evidence and competing “arguments” as to interpretation of the evidence. __________________________________________________________________________________________

Pelves in anteroposterior  (front to back) (top row) and axial views (bottom row).

Fig. 2 Changes in female pelvis over 4.4 million year time span in 6 species. Chimpanzees are NOT our ancestors and are not in our evolutionary group. The apes shown are in our group, the Hominins. Note the birth canal first widens transversely (side to side),  but from Au. afarensis to H. sapiens only anteroposterior (front to back) deepening occurs (adapted from Bergé and Goularas40, Lovejoy et al41 and Simpson et al42, with permission). In Darwin’s day, only the specimens far right and far left were known.

From left to right: Chimpanzee (Pan troglodytes), (Anthropoid pelvis)

Ardi (Ardipithecusramidus, (ape species) 4.4 million years ago), (Anthropoid Pelvis)

Lucy (Australopithecus afarensis, (ape species) 3.2 million years ago), (Platypelloid Pelvis – rare in modern females and requires C-section)

Australopithecus africanus (ape species) (2.7 million years ago), (Becoming less Platypelloid as pelvis becomes more narrow)

Homo erectus (human species) (1.2 million years ago) (first “Gynecoid” Pelvis (?)

and Homo sapiens; there are between 2-4 “types” in modern females, according to the Caldwell-Malloy system, from 1933, with various “combination types” in individual women. (There are more human species, such as “Neanderthal” – not shown here.)

The Caldwell-Malloy classification of modern female pelvis types, 1933.

It is the modern Android “male” pelvis type that is  causing problems.


Below: comparison of lower skeleton, Chimp, the Australopithecine apes and modern Homo sapiens. It’s easy to see that although we share a distant common ancestor with chimpanzees, we are not on the same evolutionary path. Our distinct path began with bipedal apes.


This illustrates a comparison between an ape pelvis (called “Lucy” – (Australopithecus afarensis) although “she” may be a “he” – misidentified?) and Homo erectus, a “human” species over which there is much disagreement as to whether or not it is our direct ancestor. By the time of this H. erectus fossil pelvis, brain size had increased, and due to more advanced bipedalism, the pelvis is more narrow, producing a more “round” opening – what is today called a Gynecoid pelvis type. (It has been “assumed” that the gynecoid pelvis only appeared when Homo sapiens evolved) This is considered to be the pelvis that best provides for successful vaginal delivery.

Body shape, fat distribution, and body composition: Just as in males who developed a characteristic body shape, girls also respond to rising levels of estrogen. The lower half of the pelvis widens to provide a larger birth canal. This results in a widening of the hips and the characteristic hour glass shape of the female form. Fat tissues increases compared to males…especially in the breasts, hips, buttocks, thighs, upper arms and pubis. On average, by age 10 girls have 6% more body fat than boys. Source: Bacha, Saad, Gungor, Janosky, & Arslanian, 2002.

The “Android” (male) pelvis is the result of a “lack of” female development (widening of pelvis at puberty). The pelvis remains a “male type” pelvis which is obviously not adapted to pregnancy and birth! Vaginal delivery is difficult. A C-section is often required or chosen.

Why does the “Android” pelvis appear in modern Homo sapiens? Next post!