[Agrippa]

Originally Posted by bioblitzkrieg

agrippa, one question, im not sure why fuller lips would fall under a progressive trait, since early hominids and sapiens had fuller lips "didnt they?"

No they didnt. Interestingly, some of the more primitive variants of Bambutids and Australids, some of the most primtive variants of modern mankind, have broader mouths with thinner lips.

Compare f.e. the extremes of East Africa, the relatively progressive Tutsis with the primitive-infantile Twa (the Twa are less extreme though than the more typical Bambutid ethnicities like the Mbuti):

(From "Rassengeschichte der Menschheit")

Note the relative unimportance of lip size and thickness in comparison to other traits for the general impression and classification as well as the combination of broad and partly thinner-drier looking mouths in the Twa group. More pronounced in more extrem Bambutid examples like this one:

wouldnt it be the retaining of a primitive trait to possess fuller lips, When one envisions a peak type progressive, smaller and less fuller lips come to mind. Like the progressive nordid you posted on this thread, his lips are thin in comparison with the negrid shown, yet according to what you stated, the negrid's lips would be progressive, even over the thin lips of the nordid?

In many UP types full lips are present, like the actress liv ullman, does this serve as something in the realm of sexual selection?

Neomorphic and progressive traits can be also those, in my definition, which are new and at least not disadvantageous for a general, versatile and active adaptation. So traits being selected by sexual selection for the purpose of being sexually attractive for other individuals are per progressive for two reasons, namely for being new and advantageous in the intraspecific competition as along as they are not disadvantageous for another, more important and longer term aspect of biological adaptation. F.e. its no option for females to get larger and larger breasts, even if they would be preferred by males for exactly this reason. Larger female breasts would be a positive development as a sign of feminity, fertility, good nutrition, health etc. in that sense only to a certain limit, namely when the larger breasts become too much of a burden for a woman in too many other areas of her adaptiveness. So there might be a conflict of trends and competitiveness in this as well as in various other regards.

Concerning fuller lips, they are of a similar kind, though the negative functional aspects are rather limited, at least in warmer climates. Additionally there is no such such strong sexual dimorphism for this trait, which means that whereas a larger breasted female can have a hypermasculine brother, a "larger lipped female" will have in most cases a brother with the same feature. This might result, like in other traits too, in a limited "sexual type conflict because of a lack of sexual dimorphism", though larger lips are hardly that disadvantageous because of sexual selection for a male - one can discuss a more socially dominant and disciplined appearance for thinner lips or similar considerations.

In the end authors like v. Eickstedt tended to regard thinner lips being more progressive, whereas one of his scholars, Knussmann, thought of fuller lips being one of "progressive traits of the Negrid race", like others as well. So there was a certain disaccord on this matter, though full lips were rarely considered primitive by the later authors of racial typologies, but if rather infantile.
Otherwise the most common explanation was indeed sexual selection. Especially in the case of the Negrid race a specific selection of this trait as a sexual signal. So the extrme lips were rather considered the result of a more recent development in the course of sexual selection inside of the Negrid race, rather than a primitive relic of a more distant past.

Its also interesting to compare our more distant relatives with modern humans. Chimpanzees f.e. have a large mouth, but almost no or very thin (everted) lips:


They have a mouth, but no human lips which serve as a communicative and especially sexual signal:


For the whole debate it would be very interesting to think about the disadvantages of larger lips, especially for various cases of social dominance under males, male attractiveness, climate related vulnerabilities etc. But I myself dont know enough about valuable studies and sources on that matter so far, just certain speculations.

One could argue however, that thinner lips must not be primitive (they are primarily in combination with a large mouth and high upper lip) in any case of course, they can be even progressive in combination with other traits, but full lips are for sure not primitive and can be in general and on their own considered progressive, from a generalised and "Eugenic" perspective at least as long as they are not out of proportions and too extreme.