Schwartz hearkens back to earlier theories that suggest that the Darwinian model of evolution as continual and gradual adaptation to the environment glosses over gaps in the fossil record by assuming the intervening fossils simply have not been found yet. Rather, Schwartz argues, they have not been found because they don’t exist, since evolution is not necessarily gradual but often sudden, dramatic expressions of change that began on the cellular level because of radical environmental stressors-like extreme heat, cold, or crowding-years earlier.
Determining the mechanism that causes those delayed expressions of change is Schwartz’s major contribution to the evolution of the theory of evolution. The mechanism, the authors explain, is this: Environmental upheaval causes genes to mutate, and those altered genes remain in a recessive state, spreading silently through the population until offspring appear with two copies of the new mutation and change suddenly, seemingly appearing out of thin air. Those changes may be significant and beneficial (like teeth or limbs) or, more likely, kill the organism.
Why does it take an environmental drama to cause mutations? Why don’t cells subtly and constantly change in small ways over time, as Darwin suggests?
Cell biologists know the answer: Cells don’t like to change and don’t do so easily. As Schwartz and Maresca explain: Cells in their ordinary states have suites of molecules- various kinds of proteins-whose jobs are to eliminate error that might get introduced and derail the functioning of their cell. For instance, some proteins work to keep the cell membrane intact. Other proteins act as chaperones, bringing molecules to their proper locations in the cell, and so on. In short, with that kind of protection from change, it is very difficult for mutations, of whatever kind, to gain a foothold. But extreme stress pushes cells beyond their capacity to produce protective proteins, and then mutation can occur.
This revelation has enormous implications for the notion that organisms routinely change to adapt to the environment. Actually, Schwartz argues, it is the environment that knocks them off their equilibrium and as likely ultimately kills them as changes them. And so they are being rocked by the environment, not adapting to it.
The article’s conclusions also have important implications for the notion of Ã¢â‚¬Å“fixingÃ¢â‚¬Â the environment to protect endangered species. While it is indeed the environment causing the mutation, the resulting organism is in an altogether different environment by the time the novelty finally escapes its recessive state and expresses itself.
Ã¢â‚¬Å“You just can’t do a quick fix on the environment to prevent extinction because the cause of the mutation occurred some time in the past, and you don’t know what the cause of the stress was at that time,Ã¢â‚¬Â Schwartz said.
Ã¢â‚¬Å“This new understanding of how organisms change provides us with an opportunity to forestall the damage we might cause by unthinking disruption of the environment,Ã¢â‚¬Â added Schwartz. Ã¢â‚¬Å“The Sudden Origins theory, buttressed by modern cell biology, underscores the need to preserve the environment-not only to enhance life today, but to protect life generations from now.Ã¢â‚¬Â
Interesting. With a name like Ã¢â‚¬Å“Sudden Origins Theory” it almost sounds like something a Creationist would cook up. Of course, it isn’t. All he has done is given the boot to one undirected, natural cause (the modern synthesis) in favor of another undirected, natural cause (an aggressive environment and abrupt changes “out of thin air”). In a nutshell his idea seems to be that the environment becomes the stressor to knock organisms out of equilibrium and embed the seeds of change into their genes, although in a recessive state. Whatever the merits of his idea, it is interesting to hear what he does say in relation to Neo-Darwinism:
1. Mutations are generally harmful and more likely to kill an organism.
2. Cells are intricately designed to resist change and correct errors.
3. The fossil record, riddled with real gaps, debunks gradualism.
Of course, for his full view you’d have to read his book Sudden Origins: Fossils, Genes, and the Emergence of Species (John Wiley & Sons, 2000).