Ecological developmental biology (eco‐devo) explores the mechanistic relationships between the processes of individual development and environmental factors. Recent studies imply that some of these relationships have deep evolutionary origins, and may even pre‐date the divergences of the simplest extant animals, including cnidarians and sponges. Development of these early diverging metazoans is often sensitive to environmental factors, and these interactions occur in the context of conserved signaling pathways and mechanisms of tissue homeostasis whose detailed molecular logic remain elusive. Efficient methods for (...) transgenesis in cnidarians together with the ease of experimental manipulation in cnidarians and sponges make them ideal models for understanding causal relationships between environmental factors and developmental mechanisms. Here, we identify major questions at the interface between animal evolution and development and outline a road map for research aimed at identifying the mechanisms that link environmental factors to developmental mechanisms in early diverging metazoans.Also watch the Video Abstract. (shrink)

As Funayama has shown, Dharmakīrti’s successors had an animated discussion on the nature and function of the initial statement of scientific treatises in terms of its effectiveness and requisites. Arcaṭa in his comments on the initial statement of the Hetubindu considers that the initial statement, which contains the purpose of the treatise, is useless in prompting people to undertake the activity of reading the treatise because judicious people are supposed to undertake action only due to certainty which never arises (...) from something that is not a pramāṇa. For Arcaṭa, the initial statement is set forth only to dispel the objection of an opponent who criticizes the treatise for not having a purpose. Kamalaśīla criticizes Arcaṭa on this point; for him the initial statement is effective to prompt people to undertake the reading of the treatise because people act also on the basis of doubt, which arises from the initial statement that is not a pramāṇa but an abhyupāya for action. This paper attempts to consider how such doubt can cause reading by examining the debate in the Tattvasaṅgrahapañjikā and related texts. As Kamalaśīla presupposes, when people act due to doubt, they may attain the desired purpose by chance but cannot escape the risks of not attaining an desired purpose and also of attaining an undesired purpose. Taking these risks into consideration, it is reasonable for Granoff to take up Kamalaśīla’s position as an example of the maxim of kākatālīya in the introduction of her paper in the present volume. However, the probability for the readers of the Tattvasaṅgraha to achieve easy comprehension of tattva as a result of reading a full treatise, which they undertake due to doubt out of the initial statement, is higher than that for a crow being suddenly killed by a falling palm-fruit. According to Kamalaśīla, the risk of not attaining the desired purpose does not prevent people from reading because such fear equally occurs in activities based on certainty. Furthermore, there is no risk of attaining an undesired purpose from the treatise because authors are supposed to undertake action only for the sake of others. Therefore, doubt which arises from an abhyupāya can make people undertake action. (shrink)