Endless Forms Most Beautiful: The New Science of Evo Devo

What a tragic irony, that the more we understand of biology, the less we have of it to learn from and enjoy. What will be the legacy of this new century - to cherish and to protect Nature or to see butterflies and zebras and much more vanish into legend like the thylacine, moa and dodo?

Behe named this inability to explain the creation of new taxa through genetics "Darwin's black box". When the box is opened, he expects evidence of the Deity to be found. However, inside Darwin's black box resides merely another type of genetics--developmental genetics

Evolution of form is very much a matter of teaching very old genes new tricks!

As delightful as the Just So explanations are of how spots, stripes, humps and horns came to be, biology can now tell us stories about butterflies, zebras and leopards that I contend are every bit as enchanting as Kipling's fairy tales. What's more, they offer some simple, elegant truths that deepen our understanding of all animal forms, including ourselves.

I believe that the teaching of evolution and science is best served by promoting the scientific method and scientific knowledge and not by attacking religious views. The latter is a futile, counterproductive batte. However, I also believe, as many denominations have also concluded, that religion is better served by promoting and evolving its respective teachings and theologies, and not by attacking science, which is definitely a losing strategy

It isn’t precisely known when and where forks started replacing the second knife at the dining table, and goodness knows what perverse minds came up with all of those other utensils, but this little snippet of cutlery history is analogous to a broad trend in biological evolution. Namely, structures (like the fork) that evolve a dedicated function (spearing food) are often derived from a preexisting structure (the knife) that served more than one role (cutting and spearing). The duplication of the original structure (the practice of using two knives) enabled the subdivision of labor among two distinct structures. Furthermore, selected for a new purpose, the structure can then evolve further modifications and specializations.

Evo Devo has not just provided a critical missing piece of the Modern Synthesis - embryology - and integrated it with molecular genetics and traditional elements such as paleontology. The wholly unexpected nature of some of its key discoveries and the unprecedented quality and depth of evidence it has provided toward settling previously unresolved questions bestow it with a revolutionary character.

While dismembering it, perhaps you might have noted the modular design and admired the great variety of body appendages (figure 1.9). There are several aspects to lobster construction that reflect the general themes of modularity and serial homology. First, the body is organized into a head (with the eyes and mouthparts), a thorax (with walking legs), and a long tail (yum!). Second, different sections of the body possess numbers of specific appendages (antennae, claws, walking legs, swimmerets). And third, each jointed appendage is itself segmented, and different kinds of appendages have different numbers of segments overall (compare a claw with a walking leg). If you were feeling adventuresome and dissected an insect or a crab, you’d see some general similarities in body organization, segmentation, and appendages but, again, differences in the number and kind of serially homologous structures. FIG. 1.9 The diversity of the serially repeated appendages of a lobster. The antennae, claws, walking legs, swimmerets, and tail structures are all modifications of a common limb design. DRAWING BY