A follow-on to the last post.
When multicellular organisms were first expanding their internal complexity five hundred million years ago, neurological systems were evolved to co-ordinate their behavior. The key is rapid and continuous real-time communication to all constituents of the organism. How could such communication have been established in the first hominin group-organisms?
To appreciate the limitations of communication between animals selected at the level of individuals, it is enlightening to read the abstract from a classic article on the subject by Robert Seyfarth and Dorothy Cheney (2003) titled “Signalers and Receivers in Animal Communication”:
In animal communication natural selection favors callers who vocalize to affect [i.e. manipulate] the behavior of listeners and listeners who [are selected to] acquire information from vocalizations. . . . The [emotional] mechanisms that cause a signaler to vocalize do not limit a listener’s ability to extract information from the call. Whereas signalers may vocalize to change a listener’s behavior, they do not call to inform others. Listeners acquire information from signalers who do not, in the human sense, intend to provide it.Seyfarth and Cheney
In other words, in animals evolved only for the fitness of the individual, expressions are always manipulative, and understanding expression is the equivalent of eaves-dropping.
The most fundamental fact in human evolution is that upright posture is an absolute requirement for a fossil to be designated a hominin. In the oldest hominin skull fossils, the extent of upright posture is determined by the forward position of the hole in the bottom of the skull (foramen magnum) through which the spinal cord exits. Because any orthopedic surgeon can tell you that upright posture produces extreme vulnerability for injuries to the lower back (perennially among the top ER visits) and to joints in the lower limbs, it is reasonable to conclude that the evolutionary advantages of such a costly adaptation must have been central to the functioning of even the earliest hominins.
My narrative is that, from the beginning in the very first hominin species, communication became the indispensable “neurological system” for the burgeoning group-organism. For the group to begin to maintain morality through justice in the process of evolving to coordinate teamwork, the sheer volume of information that was required to be simultaneously and continuously expressed and comprehended had to increase by many orders of magnitude. Is it not reasonable to conclude that these creatures stood up to be in constant visual contact with other group members’ facial and upper body gestural expressions to coordinate their behavior, in the same manner that a musical band makes small adjustments to stay in sync? In effect the entire body evolved into an instrument of constant communication for the group-organism (an organic social system). Whether it be a high-powered negotiation or a tea party, the prototypical human configuration is a circle in which everyone can see everyone else without regard to rank. I have long thought that the circular megalithic culture in Britain, beginning in the Orkney Islands north of Scotland over six thousand years ago, and culminating with Stonehenge, reflect the deepest human impulses, whereas the pyramids reflect our ape heritage.