Why is there substantial overlap between design results and evolutionary results?
There are a number of reasons why ID exists, from an unreasonable desire to hold onto religious myths, to the amazing lack of any sort of scientific rigor in the vast majority of either their criticisms or in their “models” (this statement is not to be confused with their frequent unreasonable demands that we supply rigor where unknowns remain, while they hold themselves to be exempt from any scientific rigor). This is not the place to delve into the many evolutionary faults in the brain which keep pseudosciences like ID going, however.
One issue in the constant struggle against ID and other forms of creationism is that the inference to design in life is both an anthrocentric mistake (in that “purpose” is inferred where only evolutionary function can be demonstrated), and sometimes an honest mistaking of exquisite structures and processes as being exactly what a great intelligence would design.
Indeed, if we look at the wings of swallows and of hummingbirds, without any kind of detailed morphological and ontogenetic analysis, one might simply resort to “form follows function,” wholly within the design context in which that statement has typically been made. Or, if we were to consider the cliche more closely, we might conclude that in our experience function is first considered and analyzed, and form is then designed and specifically articulated in order to fit that function.
Yes, that is our experience, thus it is not altogether unreasonable for people who know only design processes to think that wing articulations must then have been designed. But as biologists know all too well, that is not what we see in life. More than once I’ve brought up the question of why all vertebrate wings are modifications of their ancestors’ legs, while human-designed wings are modifications of bird wings as well as having been partly designed from first principles. The answer is all too clear, which is that vertebrate wings simply evolved, and were not designed in any manner as we would expect of an intelligence operating to produce them.
Yet the overlap between design and evolution is good enough for us to use bird wings as the basis for design, as the Chinese did with their kites (which is the origin of humanity’s airfoils–or so I have been led to believe), and as the Wright brothers did after adopting previous airfoils, and by studying birds and their flight abilities on their own. So surely one must address such an overlap, partly to understand evolution, partly to understand design.
The short answer is that intelligence and design expand on what evolution (otherwise) provides. But this answer itself requires expansion. Probably a large part of the evolution of logic and rationality comes from the fact that intelligence adapted to an environment which in important ways is not the result of evolution at all. This goes back to what many people understand, the fact that mathematics–especially geometry–and cognitive abilities such as following straight lines and succession, are to a large extent ways of dealing with space and also with time. Straight lines happen to be efficient ways to get from one point to another one, hence animals tend to travel in straight lines, and predators learn that this is the case–until avoidance maneuvers kick in, that is.
Primates are believed to have evolved intelligence partly for the sake of spatial (and temporal) understanding, particularly as arboreal organisms operating within 3-D space and dealing with 3-D objects (of course all space and objects are 3-D, but lions do not need to be nearly as aware of the three-dimensionality of their plains and prey). Social living extended this intelligence to models of complex organisms and their behaviors, so that we became able to understand what another primate (or prey) is likely to do next. And at some point, primates began to use various spatial items in their surroundings to manipulate their surroundings, and a (usually fairly straight) stick extended the reach of the (usually fairly straight) forearms of the primate. It should be noted in passing that the fact that we use intelligence to understand other animals and their “purposes” is likely a big reason why many people simply assume that the forms and functions of organisms ought to be understood according to purpose–if not the purpose of an observable being, then the purpose of an unobservable being.
Yet intelligence operates quite differently than evolution, which is why using a stick can effect a quantum leap over what the little primate can do with its arms alone. Or, more importantly, from understanding evolution and its overlap with design, a stick which evolved simply to uphold leaves above other plants for a competitive advantage eventually becomes an extension of the animal’s spatial capabilities, so that increasing the extension of one’s reach is no longer tied to ancestry and the tedious and slow evolutionary growth of a primate’s arm.
Oddly (and seemingly cluelessly in the case of Behe), this gets back to what Behe stated in Darwin’s Black Box, that Darwinian evolution requires physical precursors, while design can make do with conceptual precursors. And indeed, that is exactly why we understand life to be the result of “Darwinian evolution,” for it is incapable of conceptualizing a line, or of taking up a stick to bridge the chasm between two organisms. Evolution is quite limited while dealing with the geometries of space and of designed machinery (aside from the evolution of intelligence), and it can only respond with logical brains to do what evolution could never do directly.
One could look at evolution as incrementally (if not always incrementally, overwhelmingly so) providing the forms which most animals use, while intelligence evolved to use these forms and abilities well in unevolved time and space. Thus, intelligence has evolved to understand organisms’ forms and functions (their own, and, in many cases, those of other species) in a spatial and temporal manner that is completely foreign to how evolution processes information, and it can even adopt and extend the spatio-temporal capabilities artificially. Indeed, intelligence in humans can do what evolution could never do.
The fact is that bird wings have their forms because even legs are plastic over millions of years. But bird, bat, and pterosaur, could never have come up with wings by rearranging, say, ribs into the proper form to make wings. We can. Or, like the Wright brothers, we can take trees (separated from us by hundreds of millions of years of evolution) and saw out exactly the parts needed to make an airfoil, and even to articulate this airfoil so that it can change shape somewhat like a bird wing can. Rationality can leap past inheritance, in other words, while evolution could never come up with an aluminum engine, or any such thing, yet which the Wright brothers used to power their airplance.
It should be noted also that the aluminum–and the steel–in the engine used to power the Wright brothers’ airplane, along with the design of the engine, come almost entirely from the intellect, with not even an evolutionary conceptual precursor like the wings. Intelligence evolved to analyze, and even to synthesize, articulations and ideas, so that wholly new things, like aluminum engines, could be thought up in the primate brain. This is nothing like what evolution does, which is why we distinguish designed objects from living objects both by the formers’ conceptual leaps (which may not be altogether rational), and by the almost inevitable rational aspects which exist within intelligently-designed objects.
Notably, all intelligence of which we know is inextricably tied to evolution. While evolution itself could never directly supply the leaps of logic and articulation used to analyze a bird carcase, or to create a spear with a pointy stone on the end of it, both evolution and development can shape the rational and communications abilities within animals (primarily humans, on this planet) to actually deal with knowledge of space and of bird articulations, and thus to enhance survival in this world through intelligence. Intelligence overlaps with evolution both because it is selected to understand animals of one’s own and also of other species, and because it extends and enhances the behaviors of organisms. This seems to be true to the degree that humans have actually lost many earlier behaviors and even innate capabilities, instead relying more upon intelligence itself to supply behaviors that once evolved to exist and then evolved not to exist.
Another reason for the overlap of the products of design and of evolution is simply that many of the same forms and articulations are needed simply to provide function, or at least to provide function at minimal cost. While we may have copied airfoils from birds initially, the airfoil on a supersonic airplane owes little to any organism (except for the original idea), rather it is developed from empirical and theoretical studies. Intelligence did there what evolution could never do, since the latter cannot provide the power needed for supersonic flight. That said, subsonic planes have airfoils not unlike those of bird wings, not because we’re unable to think beyond copying bird wings for subsonic flight, but because millions of years of evolution, and 100 years of intelligent design, come to basically the same solution–because there really is only one good solution (and varieties of that solution to fit different criteria for flight–which are seen in both planes and in birds).
So one of the main reasons for the overlap between design results and evolutionary results is rather prosaic and probably obvious to most who think about it–good solutions are typically few, and both evolution and design can reach many of these solutions.
Nevertheless, the differences between evolutionary processes and intelligent processes are considerable, and the limitations of evolution are severe. We can turn a tree into the body (if not the engine) of an airplane. But only animals with articulated limbs of roughly the right position and tolerably within striking distance of a wing will ever evolve wings. Even more apparent, evolution will not cause organic life-forms to evolve aluminum wings and piston engines to produce flight, while evolved intelligence has done so. Likewise, one should remember that evolution has a kind of “parallel processing” power that, albeit only over very long periods, produces wing control that human designers continue to envy. This seems to be in part because “evolvability evolves,” so that organisms can slowly change to exquisitely fit niches, like those that birds inhabit.
Finally, then, the question in biology comes down not to why evolutionary and intelligent solutions overlap meaningfully, since they would have to in order to produce functional “machinery.” The real question is why biological solutions are at once so limited when compared to intelligent design, and, very often, so much more exquisite, despite their limitations. Of course the answer is that the gradual change which predominates over the course of biological evolution can make no spatial, temporal, or rational leaps, while it refines the modifications that it does effect with a profligacy (of offspring), and via excruciatingly fine changes that is not at all easy for our rather blunt rational abilities to effect.
The limitations of evolution and the strengths of evolution are explained only in one way, through the natural selection of variations in organisms, for small modifications of the immediately preceding inheritance of organisms are the mill that grinds bird, bat, and pterosaur wings into such superb and beautiful shapes, while simultaneously preventing the adoption of unrelated forms or with any consideration of first principles.
The only way that evolution could ever produce an aluminum engine, or a wooden skeleton of an airfoil, is by evolving the spatial, temporal, and rational capacities of intelligence. That is why no vertebrate wing has been anything but the modified forelimbs of its ancestors (unless, again, we count the flying fish, which evolved gliding wings from the precursors to tetrapods’ forelimbs, the pectoral fins), while intelligence–once it evolved and developed culturally and technologically–made a huge number of leaps in capability never before seen in life.
In addition, this is why most of the ancients differentiated considerably between life and technology, not only because technology is inferior in many ways to life, but because even then technology was startlingly superior in other ways.
Unfortunately for evolution-deniers, exquisite and complex adaptations of a very limited range of forms is exactly what is expected of evolution, and not at all what is expected of design. Or, to put it into their terms, of course designers adopt and adapt solutions from life, for human intelligence both analyzes and synthesizes. The insurmountable problem for them is that life never adapts anything from an unrelated and separate (with no, or very limited, lateral transfer of genes) lineages or from first principles, abilities that an actual intelligent designer is expected to have.
This is part of a series of posts that I am combining into one long post, which may be found at Darwin’s Black Box.Darwin's Black Box comment below, or link to this permanent URL from your own site.