Neoteny and paedomorphosis .

The aquatic adaptation of newborn H. sapiens can be connected to ancestral “predestinations we still carry. In developmental biology these are phylogenetic characters in species revealed in adults that retain traits previously seen only in juveniles. It described by Lorenz (4), Morris (2) and Gould (4) of different animals, humans as well.
It is not the place to go into this in general the article itself.
In this web presentation it is extended part on itself.

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The hypothesis about aquatic reflexes of newborn H. sapiens has no sense if not connected with neoteny and paedomorphosis. In combination they are more than an age in discussion for several properties of H. sapiens. In developmental biology paedomorphosis in a species are phylogenetic characters revealed in adults that retain traits previously seen only in juveniles.

As example humans are actually thought to be paedomorphic due to a flattened face and receded lower yaw compared to other adult primates.

ab
Fig. 8 Facial neoteny original examples

This is presented in 1948 in Westenhofer¹⁰ (fig. 8a) and still repeated (with 8b) many, many times with the chimps’ baby’s stadium forming an adult human face. The photographs are from A. Naef⁶.
The comparison is repeated recently in anthropology by Penin et al⁸

Two explanations are mentioned; the extension of brains of hominin ancestors to our genus Homo (fig M. 1mln Þ now) and domestication leading to a lesser jaw and smaller set of teeth.

Fig. Meijers

The process of evolution by which increase in the length of human developmental periods has been accomplished is mentioned as neoteny. Neoteny describes effects by which paedomorphism is achieved. Ultimately it results in retention of juvenile physical characteristics in adults of a species well into maturity.
Man’s large head, flat face, round headedness, small face and teeth, absence of brow ridges, thinness of skull bones, late suture closure, relative hairlessness, thin nails, prolonged period of educability, playfulness, love of fun, and many other traits, all are mentioned as evidence of neoteny

Neotenic and paedomorphic popular states in humans are characteristics in women and widely acknowledged as desirable by men (sexual attraction, Jones³ and Morris⁵). Morris discussed this in the importance of neoteny in human socio-biology and with fig. 8 I give an example:  female facial properties are bigger eyes with more white visible, more cheek and a smaller, shorter chin, lips bigger and more red visible, hairless face and more “fully hair style. In higher developed cultures this is accentuated with makeup, lipstick , hair styling and more. Observed is that competitive females look at females (concurrence) and it influences role models.

Fig. 8 Neoteny in humans ©Meijers

Hairless and baby-like body skin in general shows the same. There are differences between different dispersed Human populations, but  “attractive is general and also cultural tailored by depilating and shaving. An enormous profitable industry is thriving on it.

Then there is the “childlike higher pitch of female voicing that plays an important role in different social aspects. It is connected to attractiveness, protection against aggressiveness and realizing care. A lot of literature is available about striking values (Feinberga et al¹) of pitch difference between males and females, and the – instinctive- use in context of many social interactions.

Al mentioned about female aspects can repeated for man in the other way. Hairy, lower voice: the lower the better, Less wide eyes, bigger chin….

Socio-biology and ethology are producing an endless list of descriptions about the interactions in H. sapiens contacts and communities.

A point to mention at last is the result of research to transcriptional neoteny in H. sapiens. Not as visible as the examples mentioned, but it is important it shows that neoteny in H. sapiens is acting considerably on separate levels (Somel et al⁹).

There is more to look into, but not all known and supposed human neotenic properties are important to the aquatic traits of our newborns I focus to. The aspect of human newborns in water in fact reminds anyway about original neotenic developmental properties as described by Lorenz ⁴ , Morris⁵ and Gould²  of different animals, humans as well. Lorenz description of neoteny is an example (cursive: Lorenz, p.133):

“The apparent exception to Dollos law* thus occurs only where neoteny affects forms whose juvenile stages are rich in ancestral characters. In other words, it only involvespalingenetic**characters that are recapitulated from ancestral forms. It was necessary to discuss all of this in some detail because human beings correspond to the juvenile stages of anthropoid apes in a large number of features, both in morphology and in the realm of innate behaviour. Because a number of these persistent juvenile features of humans are ancestral characters, authors that failed to take into account the principles of neoteny set out above have repeatedly cited them as arguments against our derivation from anthropoid apes. In reality, they do not provide such negative evidence.

He did not point to aquatic activities of newborns but his statement is significant. Neotenic in combination with paedomorphic retention of (foetal and) juvenile characters into adult life is defined as link to possible original ancestral properties. They can be connected to possible ancestral anthropoid (pre-human) apes. Important is that newborns AND adults correspond in some properties of morphology and physiology and innate behaviour components are mentioned.

         Newborn properties are frequently exempted and in my view the declaration I propose is free. The important point is not the value of the examples I described. Neoteny and paedomorphosis aspects in H. sapiens are not only the socially important ones. Many are involved in physiological and morphological properties of adults.
Aquatic adaptation of H. sapiens is involved, a paedomorph form of our neonate properties. And if aquatic adaptive behaviour in our species is comparable to Lorenz definition of neoteny, than it is allowed to connect that with ancestral characters.

Fig. 9. Myanmar: Sea-gypsy children playing. http://www.allmyanmar.com/index.html

I did mention that if my proposed hypothesis is accepted, it has no sense if the concepts neoteny and paedomorph are not connected. Accepting it means that early human ancestors could indeed have undergone forced adaptation in restricted sets of habitats leading to aquatic morphological and behavioural properties. About when and where exactly and with “whom leaves speculating.

It is important to establish not only aquatic reflexes in newborn humans. If we take the evidence ethological in consideration it presents a hint to ancestral H. sapiens behaviour in and preference for aquatic and semi-aquatic habitats for children, adolescents and adults (Niemitz⁷⁾.

I propose that juvenile aquatic properties of human newborn babies and toddlers  can be neotenic and paedomorphic examples of aquatic adapted mature H. sapiens. Newborns and little children are very quick aquatically adapted. The physiological properties do encompass diving, controlling breath, early swimming movements and floating. All H. sapiens starting as newborns or very little children to swim and dive, they continue it from adolescence to maturity. The process to develop this has as I describe a striking ethological aspect.

Swimming, diving, playing in and near water is indeed an important natural behaviour for all human stages Niemitz⁷ described. To this fits that hands free together with bipedalism can be connected to aquatic adaptations as he also mentioned. Bipedal abilities came first and after this gradually the extras of tool use and skilful dispersion with more brains in bigger skullcap. And then we have course mention long distance swimming, (very) deep diving and floating on almost everything available. Not only for playing but also to able foraging, dispersing, transporting and travelling. There are changing views that carefully can open those possible probabilities, like mentioned in Wrangham¹¹ et al.

Given that early hominins in the tropics lived in relatively dry habitats, while others occupied temperate latitudes, ripe, fleshy fruits of the type preferred by African apes would not normally have been available year round. We therefore suggest that water-associated USOs * were likely to have been key fallback foods, and that dry season access to aquatic habitats would have been an important predictor of hominin home range quality. This study differs from traditional savannah chimpanzee models of hominin origins by proposing that access to aquatic habitats was a necessary condition for adaptation to savannah habitats. It also raises the possibility that harvesting efficiency in shallow water promoted adaptations for habitual bipedalism in early hominins.

(*USO’s:aquatic or semi aquatic  underground storage organs of plants (Meijers)).

Could a next explorative activity be facilitated by ancestral aquatic adaptations as we see it in newborn H. sapiens and in the other mentioned properties? Maybe we even need to point to a strong possible option to declare the speed of world wide human dispersal along shores, riverbanks and over water to many remote islands and archipelagos.

Additions

1. * Dollo's law (1857-1931) is a hypothesis proposed in 1890 that states that evolution is not reversible, suggesting irreversibility of certain evolutionary pathways. Lorenz mentions already apparent exception. What is known now about complex DNA organisation learns that he was in some sense right. Some of your vertebrate home-box genes are much the same as in Drosophila, so who knows.... (Meijers).

** Palingenetic definition in biology:
a.     Embryonic development that reproduces ancestral features of species.
b.    Obsolete: the supposed generation of organisms from others preformed in the germ cells.

2. I want to mention at last three properties that are neotenic  and visible  paedomorphic fitting in the line I depicted:

Lack of fur preventing cooling in semi aquatic habitats (try a wet t-shirt contest yourself)

Active water repellent sebum production of newborns (and foetuses) on skin maintained in all stages up to pubertal and adult humans

Subcutaneous fat, a useful isolative aquatic adaptation for babies and adolescent humans

References

1.     Feinberga D.R.  Jonesab B.C. DeBruineac L.M. Moorea F.R. Law Smitha M.J. Cornwella R.E. Tiddemand B.P. Boothroyda L.G. Perretta D.I. 2005. The voice and face of woman: One ornament that signals quality? Evolution and Human behaviour 26 (2005) 398–408

2.      Gould SJ 1977. Ontogeny and phylogeny. President and Fellows of Harvard College USA

3.      Jones D. 1995. sexual selection physical attractiveness and facial neoteny. Cross-cultural evidence and implications. Current anthropology 36 - 5

4.      Lorenz K. 1997. The natural science of the human species. (The Russian Manuscript 1944-1948). MIT press Massachusetts USA

5.      Morris D. 1967. The naked ape. Jonathan Cape, London UK

6.      Naef a. 1926. Über die Urformen der Anthropomorphen und die Stammengeschichte des Mensenschädels, Die Naturwissenschaften 14 pp. 445-452.

7.      Niemitz C. 1991. Das geheimniss des aufrechten ganges. C. H. Beck Verlag, München BRD

8.      Penin X. Berge C.   Baylac M. 2002. Ontogenetic study of the skull in modern humans and the common chimpanzees: neotenic hypothesis reconsidered with a tridimensional Procrustes analysis. American Journal of Physical Anthropology vol 118, no 1, p 50-62.

9.      Somel M. Franz H. Yan Z. Lorenc A. Guo S. Giger T. Kelso J. Nickel B.
 Dannemann M. Bahn S. Maree J. Webster M.J. Weickert C.S. Lachmann M. Transcriptional neoteny in the human brain. PNAS  April 7, 2009 vol. 106 no. 14

10.   Westenhöfer M. 1948. Eigen weg des Menschen, die Gründlagen meiner
  Theorie vom…Carl Winter Universitätsverlag Heidelberg.

11.   Wrangham R. Cheney D. Seyfarth R. Armiento E. 2009. Shallow-water habitats as sources of fallback foods for hominins. American Journal of Physical Anthropology 140:630–64