Monday, April 21, 2014
Exit from comment view mode. Click to hide this space
11

Evolutionary Theory’s Welcome Crisis

EXETER – Those who believe that a supernatural being created the universe have never posed an intellectual challenge to evolutionary theory. But creationists, whether biblical fundamentalists or believers in “intelligent design,” do pose a threat to scientific thinking. Indeed, creationism’s insidious genius lies in its ability to reinvent evolution in its own image as a dogmatic belief system – and thus the antithesis of science.

The creationists are right about one thing: contrary to the impression given by much popular writing on the subject, the theory of evolution is in crisis. But this is a positive development, because it reflects the non-linear progress of scientific knowledge, characterized by what Thomas Kuhn described in his influential book The Structure of Scientific Revolutions as “paradigm shifts.”

For the last 70 years, the dominant paradigm in evolutionary science has been the so-called “new synthesis.” Widely publicized in recent years by Oxford evolutionary biologist Richard Dawkins, the new synthesis unites Darwin’s theory of natural selection with Mendelian genetics, which explains heredity.

The current crisis in evolutionary science does not imply complete rejection of this paradigm. Rather, it entails a major, progressive reorganization of existing knowledge, without undermining the fundamental tenets of evolutionary theory: organisms alive today developed from significantly different organisms in the distant past; dissimilar organisms may share common ancestors; and natural selection has played a crucial role in this process.

Other assumptions, however, are under threat. For example, in the traditional “tree of life” representation of evolution, the branches always move apart, never merging, implying that species’ ancestry follows a linear path, and that all evolutionary changes along this path occur within the lineage being traced. But examination of genomes – particularly microbes – has shown that genes moving between distantly related organisms are an important catalyst of evolutionary change.

Moreover, the new synthesis assumes that the main drivers of evolution are small mutations generated by chance within a species. But recent evidence suggests that large changes, caused by the absorption of a chunk of alien genetic material, may be just as significant. Indeed, the absorption of entire organisms – such as the two bacteria that formed the first eukaryotic cell (the more complex cell type found in multicellular animals) – can generate large and crucial evolutionary change.

Further destabilizing evolutionary theory is the growing realization that many factors, not just the genome, determine an individual organism’s development. Ironically, as the discovery of DNA’s structure – initially lauded as the final act in the triumph of the new synthesis – led to a better understanding of genomes’ functioning, it ended up weakening belief in their unique role in directing biological development. Those who long deplored the omission of development from evolutionary models – a decades-old critique made under the scientific banner of evolutionary developmental biology (“evo-devo”) – together with the insistence that organisms’ development draws on a wide variety of resources, have been vindicated.

Recent developments in molecular biology have put the final nail in the coffin of traditional genetic determinism. For example, epigenetics – the study of heritable modifications of the genome that do not involve alterations to the genetic code – is on the rise. And the many kinds of small RNA molecules are increasingly recognized as forming a regulatory layer above the genome.

Beyond undermining the gene-centered theories of evolution that have dominated public consciousness for several decades, these developments call for new philosophical frameworks. Traditional reductionist views of science, with their focus on “bottom-up” mechanisms, do not suffice in the quest to understand top-down and circular causality and a world of nested processes.

This brings us back to where we started. Radically rethinking evolutionary theory invariably attracts the attention of creationists, who gleefully announce that if professional advocates of Darwinism cannot agree, the concept must be in retreat. And, evolutionists, confronted with this response, tend to circle the wagons and insist that everyone is in agreement.

But nothing more clearly demonstrates that science and creationism are polar opposites than the latter’s assumption that disagreement signals failure. In fact, disagreement – and the deeper insights that result from it – enables new approaches to scientific understanding. For science, unlike for dogmatic belief systems, disagreement is to be encouraged.

Evolutionary theory’s current contretemps – and our inability to predict where the field will be in 50 years – are a cause for celebration. We should leave the creationists to their hollow convictions and happily embrace the uncertainties inherent in a truly empirical approach to understanding the world.

Exit from comment view mode. Click to hide this space
Hide Comments Hide Comments Read Comments (11)

Please login or register to post a comment

  1. CommentedDante Fernando

    This article again makes all the fatal fllaws of British-oriented beliefs that Darwin somehow understood the relationships, if any, among very complex processes like natural selection, let alone mutation and evolution.

    This kind of flawed thinking is even relflected in Hawking's beliefs that, essentially nothing was required to produce reality. This is completely laughable as he has used all his life 100 percent designs and constructs called mathematics and physics. How can one conclude that existence is not designed when the very framework used to "prove" it are 100 percent human designed branches of science. The real idiocy here is the belief that "natural selection" is even a science. Intelligent design proponents may have some wild ideas, as wild as the fact that a tourist like Darwin even had an inkling of evolution. But the fact remains that any conclusion drawn from human, intelligent designed sciences like mathematics, physics and biology will always prove intelligent design in aspects like evolution. A caveman who proved 1 million years ago quantum theories accepted today would be laughed at because he had no deep science tools then to prove his point. Why should a mere British tourist like Darwin, who even misinterpreted adaptation as "natural selection", not be laughed at considering that he has zero knowledge of genetics and epigenetics?

  2. CommentedDavid Roemer

    Natural selection only explains the adaptation of species to the environment. Not enough is known about the innovations natural selection acts upon to understand how mammals evolved from bacteria in only 3.5 billion years. The only theory that does explain common descent is creationism or ID. But there is no evidence for ID or creationism. So, IDiots compare ID with natural selection to make ID look better. Atheists go along with the scam because they don't want to admit ID is a better theory than natural selection in some sense.

  3. CommentedAndy Cox

    You make a mistake in implying that all 'creationists' are agreed, or are insistent on certain unanimous dogmas. Perhaps the dichotomy between religious people (whatever that means) and scientists (whatever that means) is not as clear or as important as the histrionic modern debate seems to require us to believe. Ok, you can find me some loudmouth, hysterical preacher from Texas and put him next to Richard Dawkins, but most normal people, whether 'religious', scientist, or neither, or both, don't see a distinct line which they have to place themselves on or the other side of. And, furthermore, they don't see the necessity or benefit for such a delineation. Hot air and straw men seem to be a particular common temptation for 'philosophers'.

  4. CommentedBob Brockie

    Dupre is raising a staw man,

    All the so-called recent crises have been known to biologists for a generation and have readily been absorbed into evolutionary theory.

    Watson-Crick and Hamiton (via Dawkins) have wrought paradigm shifts but the shift only further strengthen conventional evolutionary theory.

    No new philosophical framework is needed.


  5. CommentedBurk Braun

    "And the many kinds of small RNA molecules are increasingly recognized as forming a regulatory layer above the genome."

    Where do the RNA molecules come from? They come from the genome! This article makes a mountain out of a molehill. Yes, genetics is becoming more complicated, but there is even more continuity and less conflict or even paradigm shift than the writer implies. Take from a molecular biologist.

  6. CommentedDennis Argall

    The struggle the species has with uncertainty is ancient; its placement in the Eurosemitic psyche evident in the book of Genesis where god says you can't mention me but you can control everything else by giving it a name.

    Part of the struggle for science has to be in dealing with the problem that hypothesis, testing, conclusion etc seems to lead to dogmatic teaching, so the next round of reductionist research gets off to a questionable start.

    It is important not to fear wonderful uncertainty and room for error as the alternative to dogma. We think medical science (to focus on a field which has a very high opinion of itself) 150 years ago was ridiculous without noting that current medical science will surely be thought ridiculous in another 150 years.

    Another commentator has suggested that "...[h]umanity truly has the capability to get on top of the pyramid of nature..." I'd suggest we would do better to stop thinking we are at the top of the pyramid. The mitochondria might be at the top with their persistence over aeons, clevernesses, command roles and the way they have farmed off the databases, but species chauvinism let alone Homo sapiens chauvinism should not be part of the science value set. We have only our misplaced, end-of-line-super-being self-importance to lose.

  7. CommentedZsolt Hermann

    Indeed we are living in a very exciting, but at the same time volatile period.
    As scientific development, especially quantum physics changes our perception of reality, these new evolution theories also change the previous "flat", linear picture.
    At the same time humanity has evolved into a global, physically and virtually interconnected system, where we all depend on each other.
    One interesting aspect of evolution is the birth and development of more and more complex living creatures in order to adapt to the changing environment more effectively.
    In the 21st century we arrived to the point when Humanity is before such an evolution jump, we need to combine our talents, forces, experiences and become a mutually responsible, mutually cooperating "super organism" to climb one level up on the evolutionary chain.
    The deepening and unsolvable global crisis is a proof that on our present level we are incapable of solving problems, or handle even the institutions we ourselves built.
    Humans simply have to copy nature's example but contrary to other living creatures we have to do it consciously, using all that we collected and learnt through our development so far.
    Humanity truly has the capability to get on top of the pyramid of nature and to partner and sustain the vast natural system around, but we first we have to understand our present state, its failures and the next optimal state we are destined to arrive to. If we do not take this step by free choice, consciously, evolution will force us to do it anyway by crisis and suffering.

  8. CommentedBrandt Hardin

    Here in TN, they have taken steps though new legislation to allow creationism back into the classroom. This law turns the clock back nearly 100 years here in the seemingly unprogressive South and is simply embarrassing. There is no argument against the Theory of Evolution other than that of religious doctrine. The Monkey Law only opens the door for fanatic Christianity to creep its way back into our classrooms. You can see my visual response as a Tennessean to this absurd law on my artist’s blog at http://dregstudiosart.blogspot.com/2012/04/pulpit-in-classroom-biblical-agenda-in.html with some evolutionary art and a little bit of simple logic.

  9. CommentedVictor Stern

    Wholeheartedly agree. Non-linear thinking and logic is the next "paradigm shift" in the theory of knowledge. Our data processing capabilities are enabling a completely different perspective of concepts of causality, facticity and identity. Unfortunately, contemporary philosophers simply dont know enough science and math to express the new dynamic.

Featured