Gorillas and chimpanzees both use knuckle-walking (KW). Whether this behavior is a homologous trait inherited from their last common ancestor or the result of convergent evolution remains debated. This study investigated the biomechanics of gorilla KW by measuring ground reaction forces (GRFs) and comparing them with previously reported chimpanzee data. GRFs were recorded using two in-series force plates embedded in a horizontal beam in the outdoor enclosure of Kyoto City Zoo. Three adult gorillas voluntarily performed KW during normal activity, and 90 steady-state trials were analyzed. The results revealed interspecific differences: chimpanzees exhibited greater peak vertical GRFs in the hindlimbs, approximately 1.5 times those in the forelimbs, suggesting greater hindlimb weight support. In contrast, gorillas showed comparable peak GRFs in both limbs, with slightly higher values in the hindlimbs, indicating a more balanced weight distribution. Moreover, two individuals showed out-of-phase fluctuations in gravitational and kinetic energy of the center of mass, indicating an inverted pendulum mechanism and relatively efficient energy recovery. The distinct GRF patterns and apparent mechanical efficiency suggest that gorilla KW differs biomechanically from that of chimpanzees. These findings appear to be consistent with the hypothesis that KW in gorillas and chimpanzees evolved independently, which may suggest convergent evolution rather than shared ancestry.
This chapter examines, through the lens of an in-depth single case study, how the elements of a firm's business model could change during foreign market entry. It defines the business model concept applied in this chapter and present six different elements that have a critical role when studying business models in international context. There are several ways to define the term business model. Generally, it describes how firms create, capture, and deliver value to customers and stakeholders. The Value Network comprises the key actors within the broader ecosystem of competitors, regulators and other organisations where the firm operates that jointly create the value offered to customers by the focal firm. The next business model element, the Value Delivery, explains the connections in the ecosystem that deliver value among different actors including customers.
