Recently an article was published that attempts to defend the idea that a clear delineation can be made between proximate and ultimate processes. Here I discuss how this perspective is convenient for researchers, but ultimately leads to a flawed understanding of organisms.

First some history, the paper "On the Aims and Methods in Ethology", which proposed the 4 "whys" was largely was a response by Tinbergen to the challenge that American comparative psychology, lead by D. Lehrman and T.C. Schneirla, posed to the theoretical foundations of ethology

For Schneirla and Lehrman, development tied together the proximate with ultimate. And evolution acted on entire developmental systems that predictably construct specific phenotypes. However development, especially in birds and mammals, is difficult to study (believe me!).

A core theme to their approach is that development is a process of reciprocal causation. The continual exchange between an organisms biology and environmental context define both the individual's structural and functional phenotypes. This is also known as probabilistic epigenesis

This can be seen in social development, as being born into a social environment provides the structure and contingencies necessary for the emergence of competent behavior and physiological responses, and those behaviors and physiologies in turn create that very social environment

Developmental studies have show that reciprocal interaction between the organism and its environment are responsible for both species-typical traits and abilities, and variation between individuals. How does this relate to evolution? Because evolution is a story about variation.

Darwin’s advance in our understanding of evolution was not showing that evolution occurred (which was already widely believed) but showing that variation between individuals *in* a species is ontologically linked to variations *between* species through selection.

The unanswered question from his "On the Origins of Species" was regarding the origins of and transmission of variation. This lead to Darwin become Lamarckian by proposing a theory of acquired characteristics known as pangenesis in 1868.

Because of the unanswered questions in "Origins" theorists Baldwin, Loyd Morgan and Osborne proposed that developmentally produced variants were the leading edge of evolution by reciprocally co-constructing both the proximate environments and adaptive responses to them.

This view was widely supported by the available developmental science, development provided organisms with a general adaptive capacity, to reorganize its biology-organism-environment relationships to adapt to hear-and-now problems. Development was the engine of adaptive variation

And variation, the raw material for evolution, is continually being produced and selected, there was no need for a proximate-ultimate distinction as conserved phenotypes could enter into new relationships with the environment and acquire new functionalities. I.e. Terkel's Rats

As put in 1844 by Marx, "The animal is immediately one with its life activity. It does not distinguish itself from it. It is its life activity." Variation thus doesn't reflect what animals ARE, but what animal DO, variation isn't a "thing" it's an ontogenetic outcome of behavior.

All variation is proximate, all variation (and everything else) is produced developmentally, evolution depends on variation, a science of evolution that ignores the processes wherein variation is produced and sustained, and focuses only on selection, is telling half the story.

However, in the beginnings of ethology the explicit aim was to create two types of variants (deemed unnecessary previously) evolved and individual variants, and thus the dichotomies of our time emerged between the gene and experience, innate and learning, proximate and ultimate.

The aim of early ethology was that behavior reflected phylogenies through action patterns that were characteristic of selected species-specific biological architecture. To do this they needed to break the ontogenetic continuity between individual and species level variation.

They proposed that some unidentified inherited "program" prepared an organism for its future environment. As long as the organism was healthy this program would create a behavior. Development was delegated to a supporting versus a facultative role in shaping adaptive behavior.

This new prox-ult distinction must also have a new theory of variation, it was proposed that adaptive variants relied on the transmission of "varied programs" between gen, and that development supported these programs, but did not contributing to their average adaptive outcomes.

This used variation as a starting point, whereas researchers Schneirla, Kuo, and Gottlieb were showing that, far from playing a non-specific supporting role, proximate organism-environment interactions are necessary for specific variants to be constructed across generations.

The culmination of this was when Schneirla's student Daniel Lehrman published his famous paper, where he showed the assumption that species-typical behaviors reflected experience-independent "programs" directly conflicted with empirical evidence about behavioral development.

Without his core theoretical foundation to stand on, Niko Tinbergen, who later agreed with Lehrman, attempted to divert the developmental synthesis proposed by comparative psychologists by proposing a compromise in his "On aims and methods of Ethology".

While this paper was motivated by practicality, it diverted attention away from the comparative psychologists who proposed that development tied mechanism, function, phylogeny and adaptation together, as it was whole developmental processes that were selected!

.....more to come in a bit!

Thus, the conception of proximate-ultimate distinction is largely a social construction shaped by the controversies in the field of behavior. My main issue with the 4 "whys" is that 4 different researcher can have 4 ostensibly true perspective with no foundations for a synthesis.

Like the parable of the blind man and the elephant, where does synthesis occur, can it occur with this foundation? Or does the behavioral science need to move towards a different foundation that provides a better synthesis? (pic stolen from @freerecall)

A synthesis that recognizes the reciprocal relationship between *how* organisms acquire adaptive traits and *why* those traits are adaptive will be centered on development which both produces and sustains all traits. This synthesis is already being pioneered in these books