Re: Suppression of Sociobiology

F. Bryant Furlow (mycol1@unm.edu)
Mon, 16 Dec 1996 14:37:57 +0000

John A. Halloran wrote:

> Do you have any references that discuss the above topic? I am interested in
> researching the evolution of the vocal tract in humans as connected to
> primates adopting a wolf-like existence.

Many species have 'ritualized' vocalization displays preceeding combat.
Konrad Lorenz
took this and other non-violent agonistic interaction data to mean that
species are
designed to avoid hurting conspecifics (members of their own taxa).
Since, more
reasonable, non-group selectionist proposals have been tested, and the
one coming out
on top is Sequential Assessment. Ritualized signalling allow
well-matched competitors
to assess one another's fighting abilities before risking combat.
Escalation represents
a gathering of further information (more assessment) before fighting;
usually, animals
unlikely to win a fight walk away before the non-violent displays turn
serious.

I've proposed that vocalizations are especially promising as honest
evolved signals of
phenotypic quality and hence, fighting ability ("Neurodevelopmental
integrity and Zahavian
bioacoustics," in press in Trends in Ecology and Evolution) and
reproductive value of
soliciting (begging/crying) offspring ("Neonatal cry quality as an
honest acoustic signal of fitness," in press in Evolution and Human
Behavior). Vocalizing requires the coordinated
functioning of an array of developmentally sensitive internal phenotype,
from limbic brain to
cranial nerves, cardio-respiratory systems, and the vocal tract itself.

We found that amongst a small sample (n=19) of red junglefowl roosters,
crow pitch is
significantly correlated with comb size (comb size is a known marker of
dominance and
immunocompetency, and predicts fight outcome between roosters, with
larger combs being
favored). Perhaps crowing announces the ability of the resident
dominant male to defend
his flock from would-be challengers.

Keep in mind that vocalizations are ubiquitous throughout the order
Primates.

> What is the thinking on why wolves vocalize?

Depending on context, it may be to locate pack mates, to declare
territory occupied, etc.

Good luck with your research.

> John Halloran

Bryant, UNM Biology Dept.