He argues that if humans were to continue to evolve over thousands or millions of years, they would likely develop physical features that resemble the classic "grey alien" archetype commonly associated with UFO sightings.
Why? As a biological anthropologist, Dr Masters should know better.
We're all familiar with the large-headed, big-brained aliens and mutants from popular culture, but the biological realities make it unlikely that we're headed that way.
Evolution isn't Lamarckian. If we (for the sake of argument) use our brains more but lead less physically demanding lives than earlier generations, it doesn't cause our offspring to have larger brains and less robust bodies.
Masters also argues that certain cultural factors may also further contribute to idealizing neoteny.
The jaw and its musculature has become more gracile (less robust) in humans, probably in part due to our use of cooking.
Genes for strong jaws (and big teeth) were no longer a competitive advantage, whereas a genetic disposition to growing these robust structures necessitates the use of nutrition and physiological resources that might be better used by other structures (e.g. the brain), or dispensed with altogether (having lower nutritional requirements is a competitive advantage).
It's been hypothesised that neotenic-type features in women (large eyes [
but see below], slender jaw) mimic the features of infancy and so trigger a "nurturing"/ protective response in many men; this is found across ethnicities, as described in
"
Their Ideas of Beauty Are, on the Whole, the Same as Ours": Consistency and Variability in the Cross-Cultural Perception of Female Physical Attractiveness", Cunningham M., Roberts A.R. et al 1995, February,
Journal of Personality and Social Psychology
PDF here
https://genepi.qimr.edu.au/staff/ni...ham_FacialBeauty_Pers&SocialPsych_261-279.pdf
However, selection for neotenic features is not the whole story. Many women prefer male faces with masculinised, non-neotenous features, such as a "strong jawline". "Chinless wonder" is a derogatory term. Many women have a preference for taller men; both sexes prefer a high leg length: torso ratio in "ideal" partners, non-neotenic traits. Most men have larger penises than gorillas (or any other primate), women have permanently enlarged breasts, unlike any other mammal- again, not neotenic traits.
Cunningham et al (and many others) have found a preference, particularly amongst men, for partners with "big eyes".
This is frequently stated to be a neotenic feature.
But the reality is, there isn't much variation in adult human eye size, across age, sex and ethnicity (meaning, the average woman has
proportionately larger eyes than a man). See "
Variations in eyeball diameters of the healthy adults" [Sic], Bekerman, I., Gottlieb, P., Vaiman, M., 2014,
Journal of Opthalmology, available from PubMed, National Center for Biotechnology Information
https://pubmed.ncbi.nlm.nih.gov/25431659/#:~:text=The size of a human adult eye is,may vary from 21 mm to 27 mm.
Perceived eye size depends a lot on the eyelids and proportions of other facial features.
The very large eyes of some "Grey" descriptions are difficult to understand in terms of mammalian anatomy.
Eyes are not spherical, but their dimensions in each axis
are similar,
External Quote:
approximately 24.2 mm (transverse) × 23.7 mm (sagittal) × 22.0-24.8 mm (axial)
(axial=visual axis, front to back of eye), source as above.
This means that a "Grey's" eye, if following the pattern of homo sapiens (and our ancestors, and most other mammals) would extend back into the head at least as far as its maximum visible "length" on the face, reducing volume available for other structures-such as the brain.
This is just to illustrate my point in a simplified way (eyes and cranial vaults aren't really spherical).
The sagittal CT at right is a 41 year-old woman. A mid-section CT would show a larger brain, but wouldn't show the eye.
I
have cherry-picked "Greys" with big eyes, not all illustrations show eyes this large-
-but strangely enough, I couldn't find a photo of a real one!
Neanderthals probably had larger eyes than us,
External Quote:
we first show, using orbit size as a proxy [
13,
15], that Neanderthals had larger visual systems than contemporary AMHs.
New insights into differences in brain organization between Neanderthals and anatomically modern humans, Pearce, Stringer and Dunbar 2013,
Proceedings of the Royal Society B, Biological Sciences, via National Library of Medicine
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3619466/
and could interbreed with us, but their large eyes don't seem to have been preferentially selected for- they're not around anymore.
The tarsier is a primate with proportionately large eyes,
External Quote:
each eyeball is approximately 16 millimetres (0.63 in) in diameter and is as large as, or in some cases larger than, its entire brain
(Wikipedia, "Tarsier",
https://en.wikipedia.org/wiki/Tarsier)
But unless the Greys are dependent on catching insects at night, it's hard to think of a mechanism which would drive such an expensive investment in eye expansion.
The Greys for example may not need to be explained with evolution and the future, if they are more likely a cultural phenomenon.
I think NorCal Dave is spot on here.
There's ongoing argument about to what extent humans are evolving or not. But we are unusual as a large(-ish) sized animal that most of us who want to reproduce do, and (I'm generalising) we can be
fairly confident that our children will outlive us.
Most of us die after the peak ages of reproduction and child-rearing, so it is arguable that we're not subject to natural selection in the same way (or at least at the same rate) as "wild" species.
More generalising, but for our species it probably holds true:
Most very young men find young women with prominent secondary sexual characteristics attractive;
most very young women have crushes on young men in an analogous, although perhaps more multi-factorial, way. There are many cultural nuances to this, of course.
While trying to avoid breaking out into a rendition of Janis Ian's "At Seventeen", there's not much evidence that young adults'
idealised partner preference is motivated by a respect for intelligence per se (although perceived status, personality traits and material success might feature).
There doesn't appear to be a sociobiological drive for young adults to preferentially seek out lovers and/or spouses with disproportionately large heads in the hope that their children might be more intelligent!
As a biological anthropologist, Dr. Michael P. Masters should know this.
And in the unlikely event that human nature changes dramatically, it's not clear that "growing" bigger heads will make us more intelligent. Head size (like many of our other physical characteristics) is to some degree heritable
External Quote:
...parental HC and prenatal nutritional indicators are the most important independent variables that determine HC
(Where HC= head circumference), from Ivanovic, D.M., Leiva, B.P. et al, 2004,
Head size and intelligence, learning, nutritional status and brain development: Head, IQ, learning, nutrition and brain, Neuropsychologia 42, 8; Science Direct, Elsevier
https://www.sciencedirect.com/science/article/abs/pii/S002839320400003X?via=ihub (Not a well-written paper IMHO)
The relationship, in humans, between brain size and intelligence is more problematic, there appears to be a correlation in some studies, but not all-if the relationship exists, it isn't strong
External Quote:
A very small correlation was found between cranial capacity and intelligence; but this was shown to be the result of the confounding effects of height.
from Passingham, R.E., 1979,
Brain size and intelligence in man,
Brain Behavior and Evolution 16, 4; PubMed (National Center for Biotechnology Information [USA]
https://pubmed.ncbi.nlm.nih.gov/526851/
Some factors which can reduce both brain size and intelligence (poor maternal nutrition, Pb/ Hg exposure, foetal alcohol exposure) are difficult to control for (and are more prevalent in disadvantaged groups); the mother is unlikely to know that the child has been affected and indications might be sub-clinical.
It's likely some brain size: intelligence studies have been confounded by the inclusion of subjects mildly affected in these ways.
And us males here shouldn't forget... women.
External Quote:
There is also an apparent paradox that there are substantial
sex differences in total brain volume... ...but little-to-no sex differences in mean intelligence
Structural brain imaging correlates of general intelligence in UK Biobank, Cox, S.R., Ritchie, S.J. et al, 2019,
Intelligence vol. 76 September-October, viewable here
https://www.sciencedirect.com/science/article/pii/S0160289619300789?via=ihub#bi0005
Our evolutionary cousins (and part-ancestors) the
Neanderthals had brains averaging
1640 cc for males, larger than us
(Hideki, Takeo et al, 2015, found
1736 cc in their specimen,
Virtual reconstruction of the Neanderthal Amud 1 cranium,
University of Zurich, PDF here
https://www.zora.uzh.ch/id/eprint/120401/6/AmudPaper.pdf)
-but their Levallois/ Mousterian stone technology shows little development over 260,000 years (approx. 300,000-40,000 yrs BP).
(Wikipedia, Mousterian
https://en.wikipedia.org/wiki/Mousterian).
Balzeau, Grimaud-Hervé et al found an average volume of
1514 cc for
early anatomically modern humans (190,000 to 25,000 years before present) in
First description of the Cro-Magnon 1 endocast and study of brain variation and evolution in anatomically modern Homo sapiens, 2013,
Bulletins et Mémoires de la Société d anthropologie de Paris, 25, 1-2, paper here
AMH brain variation (Research Gate)
Modern humans have a brain volume of approximately
1400 cc.
It would seem that in our species as a whole, intelligence (or at least the sophistication of our technology) is not dependent on brain size alone, and (from an evolutionary perspective) the brain has reduced in size while almost certainly increasing in complexity and efficiency.
With an absence of selective pressures to favour genes for physically larger heads, and evolutionary evidence that there hasn't been a trend towards larger brains, it's hard to see how Dr Masters can conclude that "Greys" match a foreseeable or likely human future.
I won't get into my doubts about the time it would take for signals to cross the long axons required in a typical Grey head, or the massive oxygen and glucose (or ketone) demands that a brain filling most of that head would require.
(Their respiratory rate must be very high, with that long, slender neck leading to a small chest- the lungs won't support a high tidal volume) .
Or the problems in delivering a baby Grey-
External Quote:
The size of the neonatal skull is large relative to the dimensions of the birth canal in the female pelvis. This is the reason why childbirth is slower and more difficult in humans than in most other primates
link "
Large heads, narrow pelvises and difficult childbirth in humans: Adaptations in human morphology explain why", author not named but article references Barbara Fischer and Philipp Mitteroecker, 2015, University of Vienna.
Maybe they have gestation to term "in vitro"- in which case why are they obsessed with our reproductive systems?
Before I go, what about this for a Grey, well,
Green candidate? Perhaps unlikely, I doubt if he was known in the USA-
-The Mekon AKA the Mekon of Mekonta, evil leader of the Treens of Venus' northern hemisphere,
who first appeared in
The Eagle comic from issue 30 (November 1950) in the serial strip "
Dan Dare, Pilot of the Future"
https://en.wikipedia.org/wiki/The_Mekon and resurrected several times since (notably in cult British comic
2000 AD in 1977)
A quick aside:
The same strip also gave us the Therons, the (mainly) peaceful, permatanned and highly cultured inhabitants of Venus' southern hemisphere. I don't know when they were introduced- I'd guess not long after The Mekon in 1950, as they share a planet...
...and on 20th November 1952, George Adamski claimed to have met Orthon, a peaceful messenger from Venus...
External Quote:
Adamski described Orthon as being a medium-height
humanoid with long blond hair and
tanned skin
https://en.wikipedia.org/wiki/George_Adamski