Plants and Animals: Convergent Evolution in Action?

Abstract

The Aristotelian-Linnean heritage of our current sciences is tightly associated with a view of automata-like passive plants lacking active sensory-driven lifestyles. Charles Darwin made the first attempt to escape from this "Aristotelian trap." Although his work on plants stimulated lively research into plant tropisms and hormones, his unconventional view of plants was largely ignored by the mainstream of plant sciences until recently. Darwin witnessed early studies on electrical signaling in plants, including plant action potentials. Nevertheless, this important and well-developed field of plant sciences was almost wiped out following the publication of the controversial book The Secret Life of Plants in the 1970s. The resulting "esoteric stigma" hindered the further development of this branch of plant sciences. Recently, advances in cell and molecular biology as well as in ecology led to the birth of plant neurobiology, which aims to study plants in their full sensory and communicative complexity. New concepts are needed and new questions must be asked in order to advance our still rudimentary understanding of plants.It is hardly an exaggeration to say that the tip of the radicle thus endowed [with sensitivity] and having the power of directing the movements of the adjoining parts, acts like the brain of one of the lower animals; the brain being seated within the anterior end of the body, receiving impressions from the sense-organs, and directing the several movememnts.

Microorganism and filamentous fungi drive evolution of plant synapses

“…The body of flowering plants has a clear polarity, with the root apices forming the sensory pole, specialized in searching for water and mineral nutrients, and the shoot apices forming the reproductive pole, specialized in sexual reproduction (Baluška et al, 2006; Baluška and Mancuso, 2009a,b). The heterogeneous and patchy nature of soils, when nutritionally rich patches are located close to nutritionally poor and dry (or even toxic) soil portions, presents a difficult challenge for roots (Shemesh et al, 2010) in their major task of finding and acquiring enough nutrition so as to feed the whole plant.…”

“…In the evolutionary history of land plants, there is a clear tendency toward an increased sophistication of plant behavior (Trewavas, 2005, 2009; Brenner et al, 2006; Baluška and Mancuso, 2009a,b; Karban and Shiojiri, 2010). For instance, as noted above, complex plant bodies of modern plants are well integrated via long-distance signaling and communication (Baluška, 2013) to effect and coordinate behaviors important for survival, such as collective defenses against predators and foraging for soil nutrients, and reproduction, such as pollinator attraction or seed dispersal.…”

“…to limit and correct errors in signal detection and performance, among other phenomena (Trewavas, 2003). Such highly integrated social and cognitive-like traits presumably evolved in plants to allow them to interact with other plants, microorganisms, and even higher animals, including us humans (Trewavas, 2005, 2009; Brenner et al, 2006; Baluška and Mancuso, 2009a,b; Karban and Shiojiri, 2010; Calvo Garzón and Keijzer, 2011; Trewavas and Baluška, 2011). As previously discussed, significant aspects of plant structure and function which contribute to intelligent plant behavior can be traced to early evolutionary relationships with pathogenic and symbiotic microorganisms and fungi.…”

A Statistical Description of Plant Shoot Architecture

“…These properties allow complex arbors to be generated by only varying a few parameters, offering a potentially very simple way to form diverse neural circuits [61]. The fact that neural and plant branching structures share similar topological properties offers another correspondence contributing to the field of plant neurobiology [62, 63]. …”

Green symphonies: a call for studies on acoustic communication in plants

“…In conclusion, a considerable body of evidence emerging from contemporary research in the plant sciences is increasingly recognizing plants as highly sensitive organisms that perceive, assess, interact, and even facilitate each other by actively acquiring information from their environment (Karban 2008; Baluška 2009; Trewavas 2009). We now know, for example, that when attacked, plants “cry for help” by producing volatiles that attract carnivorous enemies of the attacking herbivores (Dicke 2009); and on the other hand, parasitic plants can recognize their prey at a distance and evaluate their nutritional value before deciding to invade them (Kelly 1992; Koch et al 2004).…”