Today is Darwin Day, marking the birthday of Charles Darwin, who is celebrated around the world as a secular saint. Everywhere there will be eulogies to neo-Darwinism as a philosophy, touting the support it provides to the mechanistic worldview and the notion that life is an artifact of time and chance. Darwinism in that sense, almost akin to a faith, is indeed going strong.

Yet Darwinism as a scientific theory remains, as it always has been, a highly speculative evolutionary model. My new book, Evolution: Still a Theory in Crisis, makes that clear. I document in detail old ideas and new research that come together to severely undermine classic Darwinism and point to a new non-Darwinian paradigm for biology in the 21st century.

As the book shows, key features of the biological realm flatly contradict the Darwinian mechanism of natural selection and the notion that all features of living things are or were in some ancestral form adaptive. My new book is a sequel to my 1985 work, Evolution: A Theory in Crisis, and it shows how the crisis has deepened over the past three decades.

To understand the core weakness of the Darwinian worldview, it is important to understand what Darwinian natural selection requires. The process will work its magic, building up functional structures in organisms, only when two very strict conditions are met: First, the structure must be adaptive — that is, helpful to the organism in flourishing in its environment — and second, there must be a continuum of structures, functional all along the way, leading from an ancestor species to the descendent.

That is, the thing we are trying to explain must in some way help the creature survive, and between the creature and the creature’s ancestor there must be a gradual change, each step of which is stable and enhances fitness, or success in reproduction.

Problem number one is that there are a great number of complex structures in nature that are not led up to by known functional pathways, and imagining what these pathways might have been is in most cases very hard. But this challenge is greatly compounded by an additional problem: that in many cases complex structures convey not the slightest evidence that they ever performed an adaptive function in putative ancestral forms. This may come as a surprise to the student of evolution. The trade language of biology has focused on the concepts of adaptation, fitness, and utility for so long that it has in a sense blinded us to the universe of apparently non-adaptive order that permeates the entire organic realm.

For example, what is the adaptive fitness of the shape of a maple leaf? Or the shape of any leaf, for that matter? Nor are examples of seemingly non-adaptive order limited to the shapes of leaves. Some of the best examples are embedded deep within the biological world — among the characteristics that define and separate the basic kinds or types of plants and animals from each other.

Consider the pentadactyl (five-finger) design of the tetrapod limb, witnessed in the human arm and leg: one bone (the humerus in the upper arm, the femur in the upper leg), two bones (the radius and ulna in your lower arm, the tibia and fibula in the lower leg ), five fingers and five toes. This unique design occurs in the fore and hind limbs of all tetrapod (four-limbed) vertebrates, including human beings.

It is clear that in all tetrapod limbs the same basic design has been adapted to very different uses. However, given that the adaptive forms of the fore and hind limbs differ to some degree in every known tetrapod, it is very difficult to explain how the underlying pattern could have been arrived at so as to serve some adaptive end in a hypothetical fore and hind limb of an ancestral tetrapod. The Darwinian explanation, attributing the underlying structure to previous rounds of natural selection, is self-evidently ad hoc.

If we can’t explain what specific adaptive function the pentadactyl design serves in any known extant or extinct species of tetrapod, there are no grounds for the Darwinian claim that there was some hypothetical species in some hypothetical environment where this unique design did serve some mysteriously obscure adaptive function in both limbs. In this case, even “just so stories” can’t legitimate the Darwinian account.

The challenge to the Darwinian framework is not restricted to the tetrapod limb, but applies almost universally to a veritable universe of other novel structures — the insect body plan, the concentric whorl pattern underlying all flowers, and the enucleated red blood cell found in all mammals, which was the subject of my own doctoral work at King’s College in London.

Contributing further to the challenge inherent in so much non-adaptive order are revelations from the new field of evolutionary developmental biology (evo-devo). We now know that the paths of evolution have been highly constrained by a set of universally conserved developmental genetic mechanisms that transcend any immediate adaptive utility. Moreover, evo-devo implies that in the case of many novelties, internal constraints have played a decisive role in evolutionary origins.

In my new book, I detail vast quantities of evidence from the most up-to-date scientific literature, all supporting the radical idea that Darwinism played a very minor role in the history of life, and that evolutionary biology in the 21st century will have to seek an entirely new causal framework.

Darwinists will of course continue to insist that classic Darwinism can provide a completely plausible explanation of all evolutionary phenomena. But the reality is that Darwin’s theory is well past its “sell by” date. By Darwin Day next year, we can confidently predict the situation will appear no less dire, and likely even more so.

Editor’s note: Get your copy of Evolution: Still a Theory in Crisis now. For a limited time, you’ll enjoy a 30 percent discount at CreateSpace by using the discount code QBDHMYJH.

Image credit: © highwaystarz / Dollar Photo Club.