“Throwing the Stone.”

Chimpanzee accumulative stone throwing

The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and the...

Ray Shooting and Stone Throwing

Stone Throwing in the Glass House

A small girl with a unique genetic syndrome lies in bed since birth. Her brain does not work. She is in a persistent vegetative state. Recurrent seizures punctuate her intractable epilepsy. She shows no meaningful interaction. Her breathing is insufficient. Upper airway obstruction, repeated aspiration events, chronic lung disease, and scoliosis make her struggle to breathe. Her parents never w...

Spontaneous planning for future stone throwing by a male chimpanzee

needs to account for gravitational pull, but task-level control should be adaptive and ignore such static inputs. The neurobiology of this sort of parallel control architecture has yet to be fully worked out in any animal. Invertebrates display complex and robust behavioral equilibrium reflexes with extremely limited neural resources, a paradox which serves to experimentally highlight the under...

Parabola Separation Queries and their Application to Stone Throwing

Given two sets A and B of m non-intersecting line segments in the plane, we show how to compute in O(m logm) time a data structure that uses O(m) space and allows to answer the following query in O(logm) time: Given a parabola γ : y = ax+bx+c, does γ separate A and B? This structure can be used to build a data structure that stores a simple polygon and allows ray-shooting queries along paraboli...