Humans Are Written In the Laws of Creation

There is nothing random about Evolution.

Where is life going? In the 1980s, Harvard biologist Stephen Jay Gould said that life is going nowhere. Evolution is unrepeatable, argued Gould, and if you reran the experiment of life from the beginning, you would never get the same thing twice—you certainly would never get anything like human beings again. According to Gould and many others in the 80s, the path that life took on Earth was extremely improbable and deeply dependent on chance genetic mutations and accidental circumstances of history. The outcome of evolution on Earth was not inevitable, and lifeforms who got lucky were simply those that ducked the scythe of the grim reaper of extinction.

While evolution has long been portrayed as a process that is, at its very core, undirected and unguided, forty years after Gould’s conclusion, the situation looks quite different. Numerous studies have now shown directed mutations in evolution, cases of evolutionary convergence are ubiquitous, and many scientists even believe that extra-terrestrial life—if such life exists—will be based on the same biochemistry and the same genetic code as us. Some scientists even argue that something like human beings is a cosmic evolutionary inevitability. Far from our appearance in this world being random, then, recent science has disclosed that the evolutionary dice are loaded. 

Will ET have DNA?

In 2001, molecular biologist Norman Pace argued for “the universal nature of biochemistry.” According to Pace, “it seems likely that the basic building blocks of life anywhere will be similar to our own.” Thus, says Pace, if we travel to distant planets “and find living creatures there, and read their rRNA genes, we should not be surprised if the sequences fall into our own relatedness group, as articulated in the tree of life.” 

Investigating randomized possible genetic codes to see if a better alternative could be found, molecular biologist Stephen Freeland and his colleagues compared the biological code with millions of random variations. Freeland and his fellow researchers discovered that the genetic code found on Earth is “a global optimum for error minimization: the best of all possible codes.” The genetic code appears to be universal, and the arrangement of the code “is highly non-random.” This means that it is quite likely that life on other planets would not only have DNA as its replicating molecule but that it would also have the same genetic code as all life on earth.

The Expected Arrival of the Fittest

Beginning in the 1990s, scientists who study evolutionary developmental biology (or Evo-Devo) have increasingly stressed the directedness of evolutionary processes. Evo-Devo biologists Manfred Laubichler and Jane Maienschein describe how “developmental mechanisms per se constrain variation in non-random ways.” And even when mutations occur at random, developmental processes constrain such chance genetic events to express them in non-random ways.

Evo-Devo scientists have likewise shown that the variety and types of animal body plans are not random. While classical evolutionary theory may “explain the survival of the fittest,” say biologists Scott Gilbert and David Epel, “it could not explain the arrival of the fittest.” Gilbert discusses how “all the different body plans seen in the animal kingdom” are encompassed in “only about three dozen major animal lineages.” Gilbert asks, “Why don’t we see more body plans among the living animals,” even though “one can easily envision other body plans by imagining animals that do not exist?” The answer, he says, has to do with “the constraints that development imposes on evolution.”

Many Biological Paths that Lead to the Same Destination

The observation that deeper principles guide the historical path of life has similarly been emphasized by scientists who study a phenomenon known as evolutionary convergence. Evolutionary convergence is when, in the course of evolutionary history, two or more lineages of organisms arrive at the same biological destination from very different starting points. 

Researchers have found instances of evolutionary convergence “at all levels of organismal design,” explains biologist Patricia Willmer. “From cell chemistry and microstructure to cell types, organ systems, and whole body plans,” evolutionary convergence is ubiquitous.

In a study published in the journal Nature, evolutionary biologists Kouroh Salehi-Ashtiani and Jack Szostak have shown that the Hammerhead ribozyme—a class of RNA molecules that can specifically cleave other RNA sequences—has evolved independently numerous times in species that are not related through descent. Salehi-Ashtiani and Szostak explain that “Our results show that, despite the dominance of contingency (historical accident) in some recent discussions of evolutionary mechanisms [here they cite S. J. Gould], purely chemical constraints can lead to the repeated evolution of the same macromolecular structures.”

In the July 2013 issue of Science, researchers investigating several species of Anolis lizards on four Caribbean islands reported that their work demonstrates that “although the set of species that have evolved on each island is not identical, they are very similar, much more so than would be expected by chance. In other words, despite evolutionarily radiating independently on each island, the outcome has been deterministic—species diversifying independently in similar environments do, indeed, produce highly similar evolutionary outcomes.”

The camera-like eye (found in mammals, cephalopods, and other families) has also evolved independently at least six times, and even their mechanisms of seeing—in terms of the neural architecture—and molecular cascades have also shown multiple convergences. This remarkable similarity of the structures and physiology, despite the complex nature of the camera eye, is especially surprising since the common ancestor between the vertebrates, the octopus, and the other groups exhibiting such eyes lived about 580 million years ago in the Cambrian and could not possibly have possessed a complex camera eye. 

Biological research has revealed that there are even “striking convergences” between human, bird, whale, and insect music in terms of melody, harmony, tone, structure, timbre, and so on. Biologist and musicologist Patricia Gray observes, “The undersea songs of humpback whales are similar in structure to bird and human songs and prove that these marine mammals are inveterate composers…Humpback whale songs are constructed according to laws that are strikingly similar to those adopted by human composers.” This leads Gray to wonder, “Is there a universal music awaiting discovery?” Considering the convergent “similarities among human music, bird song, and whale song,” Gray and her fellow researchers are very tempted to believe that this is indeed the case.

For many, such examples indicate that there are stable points in biology towards which evolution navigates. Reflecting upon numerous instances of evolutionary convergence, biologist George McGhee concludes, “First, the view that the evolutionary process is nonrepeating…is demonstrably false,” and “second, the view that evolution is entirely historically contingent, and thus unpredictable (and nonrepeating), is demonstrably false.” Moreover, such examples of convergence suggest that there are stable points towards which evolution navigates, that evolution is highly directional, and that it merely discovers forms that are written in the laws of nature.

If the stable points along the trajectory of evolutionary history are written in the very constants and laws of the cosmos, then certain outcomes are not only predictable but also inevitable. As Cambridge biologist Simon Conway Morris observes, “life navigates towards certain inevitable solutions,” and “evolution must follow a metaphorical map of highly restricted possibilities.” Among these stable patterns towards which the history of life navigates, says Conway Morris, “is that of the humanoid.” Humans are written in the laws of creation, and, explains Conway Morris, “the constraints of evolution and the ubiquity of convergence make the emergence of something like human beings a near-inevitability.” Contrary to Stephen J. Gould, “the contingencies of biological history will make no long-term difference to the outcome.”