Naked Science Forum
On the Lighter Side => New Theories => Topic started by: smiletheory on 22/12/2021 16:29:41
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What do humans and Tyrannosaurus Rex have in common? The juvenile appearance of both species may be predictive of its fully adapted appearance. Dean Abel, 2021
Abstract
Mammals adapt to their environment by gradually changing body shape and appearance over the course of generations. This has resulted in the evolution of predictable, latitude specific characteristics, known as ecological rules/adaptations. This paper will argue the suggestion that the adaptive ‘cute’ human infant appearance, closely maps the location and appearance, of all known high latitude mammalian adaptations. Cuteness is therefore similar to a caricature of a cold adapted high latitude homosapien.
Introduction
The Human juvenile form is a combination of neotenous characteristics known universally as, "cute". Konrad Lorenz deconstructed cuteness into its constituent parts known as the kindchenschema, (1). The large head, large eyes, small nose, thick body, short arms and legs is a combination of characteristics which elicit a protective response from care givers and others. Neoteny is the adult resemblance to the juvenile form, (2) Humans are known as the most neotenous primate because adult humans resemble our juvenile/youthful proportions and appearance, more closely than any other primate. This means that successive species of primates have gradually evolved to look younger for longer, with humans looking the youngest for the longest amount of time. Another species which evolved neotenously are the Theropods. The Theropoda were a species of three toed, hollow boned dinosaurs, which included velociraptors, archaeopteryx and tyrannosaurus rex. Dinosaurs appeared in the fossil record 245 million years ago, theropods evolved approximately 180 million years ago and birds are believed to have evolved from theropods 30 million years later. The juvenile appearance of Tyrannosaurus Rex was covered in feathers, which it then lost as it matured, (3). This suggests that a juvenile Tyrannosaurus rex, resembled a descendant which would not exist for another 30 million years; birds. This would suggest that theropods evolved neotenously, as they now resemble their juvenile appearance. This would mean that birds are the most neotenous dinosaur, because their adult form, resembles a juvenile dinosaur.
Fully Adapted Appearance
Organisms adapt to the ecosystem within which they exist. An ecosystem is comprised of multiple ecological pressures such as weather, temperature or predators etc. The adaptations which result from these ecological pressures over the course of generations, are known as ecological rules, (4). Below is a comparison between ecological rules which apply to mammals at higher latitudes and the kindchenschema. Babies are born with disproportionately large heads and nearly adult sized eyeballs, (5). Pearce et al 2012, found that human populations that have adapted to higher latitudes, have larger heads and larger eyeballs, (6). Babies are born with smaller noses (7), and populations at higher latitudes have developed smaller noses, (8). Babies are born with disproportionately short arms and legs, (9). Researchers have found that human limb length follows a latitudinal gradient, with shorter limb length at higher latitudes, (10). Allen J, 1877, found that many mammals living at higher latitudes have shorter arms, legs and appendages than mammals of the same species at lower latitudes, (11)(12). Babies are born with increased levels of 'puppy-fat', (13). Researchers have found that high latitude populations have higher levels of subcutaneous fat, situated on the limbs and abdomen, (14). Bergmann C, 1847, found that mammals living at higher latitudes have larger, thicker bodies than those of lower latitude species, (15)(16). Babies of all populations are often born with reduced skin pigmentation for a limited period, (17). Gloger C, 1833, found that external pigmentation follows a latitudinal gradient, with reduced pigmentation at higher latitudes, (18). Humans are most closely related to chimpanzees, (19). Chimpanzees discern age from facial coloration, with lighter skin denoting youth, (20). Babies are born infertile and fertility follows a latitudinal gradient, with populations at higher latitudes being less fertile, (21). Researchers have found that the human Y chromosome which triggers embryonic development as male, is disappearing and will impact human fertility over the next 4.6m years, (22).
Is The Kindchenschema Biological Mimicry of Multiple High Latitude Ecological Rules?
Biological mimicry is described as a beneficial resemblance to another organism or object, (23). Biological mimicry occurs throughout nature. For example the defenceless cheetah cub, resembles its' fearsome honey badger neighbour. In the same way that a juvenile T Rex resembled and then evolved into todays birds, could homosapiens juvenile physical characteristics, be biological mimicry of our fully evolved/adapted characteristics?
Conclusion
Is it reasonable to suggest that Homosapiens juvenile appearance is actually biological mimicry of a completely cold climate adapted homosapien? The high latitude environment has predictable effects on human evolution, based on the latitudinal ecological rules. During our brief period of juvenile cuteness we closely resemble these predictable effects and extensive research has found that these proportions are adaptive socially and environmentally. So why do we value cold adaptation so highly? Higher latitudes have two unique characteristics, lower temperatures and stronger gravity. The lower temperatures increase our production of white fat, which is essential for powering our big brains, (24). Humans are the fattest primate and the evolution of large brains in homosapien, has comes at a considerable metabolic cost, which has been supported by a preponderance of white fat. High latitude populations store white fat around the mid section, (14). Secondly, the strength of gravity increases as we travel away from the equator. For example the strength of gravity varies from as much as 9.81m/s in Oslo (just over 1kg), to as little as 9.77m/s in Ethiopia, (25). 100th of a Newton is approximately 1 gram, so gravity at 9.81ms is approximately one gram heavier than at 9.80ms, (the weight of a paper clip). This means that the soft tissues weighing 10 grams in Ethiopia, weigh 14 grams in Oslo. Aloe et al found that heavier gravity is linked to increases in the size of the visual cortex and visual system 26). Heavier gravity is also linked to increased dopamine levels, (27) and higher BDNF levels, (28). Dopamine levels also follow a latitudinal gradient, with higher dopamine levels at higher latitudes, (29). A reduction of gravitational strength, is linked to reduced dopamine levels, (30). The expansion of the dopaminergic system, (31), has been closely linked to the origins of human intelligence, (32). It is arguable that a priority of human evolution has been the growth of the cerebral cortex. The neurochemicals which positively respond to gravity have been an essential part of the evolution of human intelligence.
Gravitational forces on the body are further increased by bipedalism. Walking on two legs subjects the soft tissues of bipeds to stronger impact forces than those of quadrupeds, (33), these forces triple during running and can reach as much as 8 g, (34). This means that bipedalism somewhat mimics living at a higher latitude, due to the increase of gravitational forces on the body. The bodies soft tissues respond to as little as 0.6 g of weight, (35).
A person that is aware of the characteristics of the kindchenschema, can accurately predict multiple high latitude ecological rules; that is quite a coincidence.
References
(1), Lorenz, Konrad. Studies in Animal and Human Behavior. Cambridge, MA: Harvard Univ Press;1971
(2), Heterochrony in human evolution: The case for neoteny reconsidered, Brian T Shea, 1989
(3) Feathered dinosaurs from china and the origin of birds. Xing Xu, 2004.
(4), Ecogeographical rules: Elements of a synthesis. Kevin J Gaston, Steven Chown, Karl Evan's, 2007.
(5) Distribution and Determinants of Eye Size and Shape in Newborn Children: A Magnetic Resonance Imaging Analysis. Laurence Shen Lim et al 2013
(6), Latitudinal variation in light levels drives human visual system size. E Pearce, R Dunbar 2012
(7), Rhinosurgery in children: developmental and surgical aspects of the growing nose. C, vereoerd, H.L. Verwoed-Verhoef, 2010
(8), Investigating the case of human nose shape and climate adaptation, Arslan A. Zaidi, et al 2017
(9), Ecogeographic patterns in fetal limb proportions. Erin B waxenbaum et al 2019.
(10), Developmental variation in ecogeographic body proportions Libby W Cowgill et al. Am J Phys Anthropol. 2012
(11), Allen, Joel Asaph (1877). "The influence of Physical conditions in the genesis of species". Radical Review. 1: 108–140
(12), AN INTERSPECIFIC TEST OF ALLEN'S RULE: EVOLUTIONARY IMPLICATIONS FOR ENDOTHERMIC SPECIES R.L Nudds, S. A. Oswald, 2007
(13), Body composition from birth to 4.5 months in infants born to non – obese women, Angela E Carberry, Paul B Colditz, Barbara E Lingwood, 2010
(14), Measures of body composition in blacks and whites: a comparative review, dale r Wagner, Vivian h Hayward, 2000
(15), Ecology and the origin of species, Dolph Schluter, 2001.
(16), Meiri, S.; Dayan, T. (2003-03-20). "On the validity of Bergmann's rule". Journal of Biogeography. 30 (3): 331–351. doi:10.1046/j.1365-2699.2003.00837.x
(17), Skin Reflectance of Newborn Infants from 25 to 44 Weeks Gestational Age Peter W. Post, Alfred N. Krauss, Stephanie Waldman and Peter A. M. Auld, 1976.
(18), A review of Gloger's rule, an ecogeographical rule of colour: definitions, interpretations and evidence; Kaspar Delhey, 2019
(19), Phylogenomic evidence of adaptive evolution in the ancestry of humans. Morris Goodman and Kirstin N. Sterner 2010
(20), Kawaguchi, Y., Nakamura, K. & Tomonaga, M. Colour matters more than shape for chimpanzees’ recognition of developmental face changes. Sci Rep 10, 18201 (2020).
(21), On the Relationship Between Fertility and Geographic Latitude: A Cross-National Study, Nigel Barber 2002
(22), Is the Y chromosome disappearing?—Both sides of the argument, Darren Griffin 2011
(23), Natural selection in mimicry, Bruce Anderson, Marinus L de Jager, 2019
(24), Chapter 1: Evolutionary Perspectives on Fat Ingestion and Metabolism in Humans, Leonard WR, Snodgrass JJ, Robertson ML. 2010.
(25), wolframalpha.com
(26), Aloe L, Fiore M, Santucci D, Amendola T, Antonelli A, Francia N, Corazzi G, Alleva E. Effect of hypergravity on the mouse basal expression of NGF and BDNF in the retina, visual cortex and geniculate nucleus: correlative aspects with NPY immunoreactivity. Neurosci Lett. 2001 Apr 13;302(1):29-32. doi: 10.1016/s0304-3940(01)01648-2. PMID: 11278104.
(27), Effect of microgravity on glial cell line-derived neurotrophic factor and cerebral dopamine neurotrophic factor gene expression in the mouse brain. A.S. Tsybko,T.V. Ilchibaeva,A.V. Kulikov,E.A. Kulikova,I.B. Krasnov,V.N. Sychev,B.S. Shenkman,N.K. Popova,V.S. Naumenko. 2015
(28), Effect of hypergravity on the mouse basal expression of NGF and BDNF in the retina, visual cortex and geniculate nucleus: correlative aspects with NPY immunoreactivity. L. Aloe et al 2001
(29) Correlation of the COMT Val158Met polymorphism with latitude and a hunter-gather lifestyle suggests culture gene coevolution and selective pressure on cognition genes due to climate, 2013
(30), Simulated microgravity subtly changes monoamine function across the rat brain, Alexandra Gros, Leandre Lavenu, Jean Luc Morel et al, 2021
(31) The Dopaminergic Mind in Human Evolution and History Reissue by Fred H. Previc (ISBN: 9780521360890).
(32) Dopamine and the Origins of Human Intelligence, Fred H.Previc, 1999
(33), Analysis of foot strike forces in chimpanzee Locomotion: Implications for the Evolution of Human Walking. Vincent Bhandal, Otto Lam, Nicholas Holowka, Nathan Thompson, Brigette Demes
(34), Gait Retraining to Reduce Lower Extremity Loading in Runners, Harrison Philip Crowell and Irene S. Davis 2011
(35), Meddev-Corp.com Gold Eyelid Implants
This is a first draft.