Handedness in Animals and Plants

Structural and functional asymmetries are traceable in every form of life, and some lateralities are homologous. Functionally speaking, the division of labour between the two halves of the brain is a basic characteristic of the nervous system that arose even before the appearance of vertebrates. The most well-known expression of this specialisation in humans is hand dominance, also known as handedness. Even if hand/limb/paw dominance is far more commonly associated with the presence of a nervous system, it is also observed in its own form in aneural organisms, such as plants. To date, little is known regarding the possible functional significance of this dominance in plants, and many questions remain open (among them, whether it reflects a generalised behavioural asymmetry). Here, we propose a comparative approach to the study of handedness, including plants, by taking advantage of the experimental models and paradigms already used to study laterality in humans and various animal species. By taking this approach, we aim to enrich our knowledge of the concept of handedness across natural kingdoms.

Ascent and Attachment in Pea Plants: A Matter of Iteration

Pea plants (Pisum sativum L.) can perceive the presence of potential supports in the environment and flexibly adapt their behavior to clasp them. How pea plants control and perfect this behavior during growth remains unexplored. Here, we attempt to fill this gap by studying the movement of the apex and the tendrils at different leaves using three-dimensional (3D) kinematical analysis. We hypothesized that plants accumulate information and resources through the circumnutation movements of each leaf. Information generates the kinematical coordinates for the final launch towards the potential support. Results suggest that developing a functional approach to grasp movement may involve an interactive trial and error process based on continuous cross-talk across leaves. This internal communication provides evidence that plants adopt plastic responses in a way that optimally corresponds to support search scenarios.

Motor cognition in plants: from thought to real experiments

Motor cognition involves the process of planning and executing goal-directed movements and recognizing, anticipating, and interpreting others' actions. Motor cognitive functions are generally associated with the presence of a brain and are ascribed only to humans and other animal species. A growing body of evidence suggests that aneural organisms, like climbing plants, exhibit behaviors driven by the intention to achieve goals, challenging our understanding of cognition. Here, we propose an inclusive perspective under motor cognition to explain climbing plants' behavior. We will first review our empirical research based on kinematical analysis to understand movement in pea plants. Then, we situate this empirical research within the current theoretical debate aimed at extending the principles of cognition to aneural organisms. A novel comparative perspective that considers the perception-action cycle, involving transforming perceived environmental elements into intended movement patterns, is provided.

Turning biology to life: some reflections

This essay presents various reflections on living systems, what they are and how they evolve, prompted by editing Teleonomy in Living Systems (a special issue of the Biological Journal of the Linnean Society). Conclusions include the suggestion that the linked notions of teleonomy and agency represent fundamental properties of matter that become apparent only when organized in the way that we consider to be that of a living system. As such, they are factors that form part of the intrinsic ‘a priori’ of living systems, as they evolve in form through space and time. Biology, the science of life and living systems, needs to be ‘biological’ if it is to be anything at all. Understanding the role of teleonomy (internal, inherent goal-seeking) will always play a necessary part in this endeavour: teleonomy represents one of the fundamental properties of living systems.

Endless forms most beautiful 2.0: teleonomy and the bioengineering of chimaeric and synthetic organisms

The rich variety of biological forms and behaviours results from one evolutionary history on Earth, via frozen accidents and selection in specific environments. This ubiquitous baggage in natural, familiar model species obscures the plasticity and swarm intelligence of cellular collectives. Significant gaps exist in our understanding of the origin of anatomical novelty, of the relationship between genome and form, and of strategies for control of large-scale structure and function in regenerative medicine and bioengineering. Analysis of living forms that have never existed before is necessary to reveal deep design principles of life as it can be. We briefly review existing examples of chimaeras, cyborgs, hybrots and other beings along the spectrum containing evolved and designed systems. To drive experimental progress in multicellular synthetic morphology, we propose teleonomic (goal-seeking, problem-solving) behaviour in diverse problem spaces as a powerful invariant across possible beings regardless of composition or origin. Cybernetic perspectives on chimaeric morphogenesis erase artificial distinctions established by past limitations of technology and imagination. We suggest that a multi-scale competency architecture facilitates evolution of robust problem-solving, living machines. Creation and analysis of novel living forms will be an essential testbed for the emerging field of diverse intelligence, with numerous implications across regenerative medicine, robotics and ethics.

Choices by organisms: on the role of freedom in behaviour and evolution

Neo-Darwinian biology has demonstrated that it is possible to construct a theory of life that excludes the role of organisms’ free choice. In a richer theory, the latter as a possibility needs to be taken into account. For that purpose, it is necessary to introduce the biological concept of choice, analyse its structure and roles, and consider some implications for biological theory. It is argued here that the conditions for free choice emerge together with umwelt—the space of synchronous options. Basically, choice does not require purpose. This leads to the conclusion that freedom is an attribute of life.