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This paper aims to compile an exhaustive list of the behavioral patterns exhibited by the chimpanzees of the Mahale Mountains National Park, Tanzania. The compilation is based on the glossary compiled by Goodall (1989), but a substantial numbers of new terms have been added. Thus, we list 316 simple anatomical terms, 81 complex anatomical terms, 37 simple functional terms, and 81 complex functional terms, in addition to 116 synonyms. The behavioral patterns are divided into eight categories on the basis of degree of universality: (1) commonly seen in both Homo and two species of Pan, (1?) commonly seen in Homo and only one species of Pan, (2) patterns common to the genus Pan but not to Homo, (3) patterns common to the chimpanzee Pan troglodytes but not the bonobo Pan paniscus, (4) patterns common to eastern (P.t. schweinfurthii) and central (P.t. troglodytes) but not western (P.t. vents) chimpanzees, (5) patterns unique to the eastern chimpanzees, P.t. schweinfurthii, (6) patterns unique to the population of Mahale, (7) patterns unique to many individuals (at least most members of an age/sex class) of M group chimpanzees, (8) patterns limited to a single (idiosyncrasy) or a few individuals of M group. It is most likely that the behavior patterns of the last common ancestor of Homo and Pan are found in Categories 1 and I? and less likely in Categories 2 and 3. It is possible that behavior patterns belonging to Categories 5, 6 or 7 are cultures.
Feathers are arranged in a precise pattern in avian skin. They first arise during development in a row along the dorsal midline, with rows of new feather buds added sequentially in a spreading wave. We show that the patterning of feathers relies on coupled fibroblast growth factor (FGF) and bone morphogenetic protein (BMP) signalling together with mesenchymal cell movement, acting in a coordinated reaction-diffusion-taxis system. This periodic patterning system is partly mechanochemical, with mechanical-chemical integration occurring through a positive feedback loop centred on FGF20, which induces cell aggregation, mechanically compressing the epidermis to rapidly intensify FGF20 expression. The travelling wave of feather formation is imposed by expanding expression of Ectodysplasin A (EDA), which initiates the expression of FGF20. The EDA wave spreads across a mesenchymal cell density gradient, triggering pattern formation by lowering the threshold of mesenchymal cells required to begin to form a feather bud. These waves, and the precise arrangement of feather primordia, are lost in the flightless emu and ostrich, though via different developmental routes. The ostrich retains the tract arrangement characteristic of birds in general but lays down feather primordia without a wave, akin to the process of hair follicle formation in mammalian embryos. The embryonic emu skin lacks sufficient cells to enact feather formation, causing failure of tract formation, and instead the entire skin gains feather primordia through a later process. This work shows that a reaction-diffusion-taxis system, integrated with mechanical processes, generates the feather array. In flighted birds, the key role of the EDA/Ectodysplasin A receptor (EDAR) pathway in vertebrate skin patterning has been recast to activate this process in a quasi-1-dimensional manner, imposing highly ordered pattern formation.
