Natural Selection as the Sum over all Histories

As evolution can be connected to the principle of least action, and if it is depicted in evolution-space versus time then it corresponds to the direction of ultimate causation. As an organism evolves and follows a path of proximate causation, if the vector is closely parallel to that of the Ultimate Causation then the changes will confer desirable attributes which will lead to further development. If, however, the variations do not occur in a direction close to that of the ultimate causation vector the evolved organism will quickly die out. Therefore Natural Selection may be viewed as similar to Feynman’s “sum over all histories”. This approach is compatible with both Neutral Theory and Selection, as it includes both positive and negative mutations and selection. Therefore, the principle of least action gives a direction, but not a purpose, to evolution.

Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus)

Yawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.

The New Human Science

All prior attempts to understand human origins, behavior, and history have led to paradoxes and dilemmas, highly resistant to resolution. This chapter reviews specific cases of failures to resolve these apparent paradoxes and dilemmas in human evolution and the social sciences. The authors argue that these failures are rooted in confusing proximate with ultimate causation. They further argue that a sound theory of human origins, behavior, and history (social coercion theory) can help to understand the human condition scientifically; specifically, this theory argues that all the unique properties of humans emerge from the unprecedented human social evolution, driven, in turn by the evolution of cost-effective coercive management of conflicts of interest. Finally, the authors argue that social coercion theory yields the first general theory of history, economics, and politics, which provides an approach to problems within the social sciences while armed with a grasp of ultimate causation. Consequently, formerly intractable scientific questions and social concerns become manageable and solvable.

From “Actual Forces” to “Token Stimuli”

The field of “coevolutionary studies” is the origin of many evocative stories in evolutionary biology, as well as a demonstration of the value of studying the ecological interactions of whole organisms and populations. This field exploded after the publication of “Butterflies and Plants: A Study in Coevolution,” a 1964 paper co-authored by entomologist Paul Ehrlich and botanist Peter Raven. However, this paper argues that the foundation for “Butterflies and Plants” was laid in the previous decades, in the work of economic entomologists, crop-plant breeders, and insect physiologists. Using the work of an influential insect physiologist, Gottfried S. Fraenkel, this paper examines the prehistory of coevolutionary studies, showing that practical research on insect feeding in the 1940s and 1950s transformed plant chemicals into active biological molecules—causal forces modeled on hormones. Insect physiologists were the first to study the effects of these molecules on insects. Yet, rather than redefining insect-plant interactions in terms of reductionist molecular causation, they sought a more integrative explanation. Not only did these insect biologists see plants as active participants in their ecological and evolutionary landscapes, but they also came to see evolutionary history as the “raison d’être” of plant molecules and insect feeding behavior. This paper expands our understanding of the generative role that physiology and molecular methods played in the development of concepts and practices in evolutionary biology. Furthermore, it contributes to a growing literature that undermines the historical division between proximate and ultimate causation in biology.