|Fitness For Cosmic Impacts?|
Bill Nye The Science Guy has been telling us about an asteroid that will miss making the graphic to the left real.
It will miss by only fifteen minutes.
In other words, we will miss a catastrophe by about a cup of coffee.
Darwin did not consider cosmic impacts, genetics, nor epigenetic impacts in terms of fitness to survive or the lack of fitness to survive.
In today's post we ask about and explore the issues concerning how a species becomes fit to survive a cosmic catastrophe such as an asteroid impact, the demise of our Sun, and the anthropogenic induced catastrophe called The Sixth Mass Extinction.
These have now become major considerations in the current scientific world within current civilization, in terms of extinctions of species.
There have been five mass extinctions, and we are well into the sixth mass extinction, the Anthropogenic Mass Extinction.
One interesting aspect of the recent asteroid impact science is that Darwin was unaware of it.
He did not know that most of the life forms existing 65 million years ago did not become extinct by failing to adapt via natural selection.
An abiotic cosmic catastrophe of non-biological proportions rendered those millions of species extinct, even though they were dominating and successful in their environment.
Something just as interesting, with just as much surprise, is that Darwin was not aware of genes either.
Yet genes became a central focus of evolutionary thought, all done in the name of Darwin and done for Darwinism itself, evidently:
What is at issue is not the fact of evolution, but its mechanisms. As Eva Jablonka and Marion Lamb are at pains to remind us in this important book, Darwin himself, a naturalist and consummate observer of living organisms, was a pluralist about such mechanisms, even embracing a version of Lamarckism - the inheritance of acquired characteristics. Conventional historiography ascribes this to his being unaware of Mendel's discoveries and so of genes. If he had known, he would have been as monolithic as have become his ultra-Darwinist followers. For them, evolution is about one thing only - genes, aka DNA.(What Darwin Really Thought, emphasis added). So Darwin did not consider cosmic impacts, genetics, nor epigenetic impacts in terms of fitness to survive or the lack of fitness to survive?
The tendency to such reductionism set in as far back as the 1930s, when evolution ceased to be defined in term of changes in organisms (phenotypes, such as the shape of the beaks amongst the Galapagos finches that Darwin studied) and instead was seen as "the rate of change of gene frequencies in a population". Francis Crick formulated what he called "the central dogma" of molecular biology as the one-way flow of information from gene (DNA) to organism.
But it was Richard Dawkins above all who captured the sense of ultra-Darwinism when he divided the living world between replicators - structures which can be accurately copied, like DNA molecules - and vehicles, the "lumbering robots" whose function is to enable that copying.
Despite the attractions of its doctrinal simplicity, important strands of biological thinking have never accepted this genocentric view of the world, and many doubt that Darwin would have either. The late Stephen Jay Gould, for example, insisted that selection acted at multiple levels, not just on individual genes, but on populations of organisms and indeed on species and ecosystems as a whole. In this perspective, Dawkins' lumbering robots become players in their own destiny.
An even more fundamental attack has come from researchers interested in how organisms develop. To appreciate the importance of this, think about the fact that humans are just under 99% genetically identical to chimpanzees, yet no one would confuse the two. The origin of the differences between the two phenotypes lies in their development, which in turn depends on which genes are switched on or off at any time - a process regulated by the cellular environment in which the genes are embedded. Genes do not exist in isolation, but as part of a web of interactions extending in time as well as space.
Indeed, as more and more is learned about the complexities of these processes, the concept of "the gene" as a reified DNA sequence tends to dissolve. What exists, as one molecular biologist put it, is not a set of discrete genes, but an entire genome. And what evolves is neither a set of genes nor a given static phenotype, but a developmental system, embedded as that system is in an even broader web of interactions with its fluctuating environment - the famous "tangled bank" of hedgerow species that Darwin invokes in the closing paragraph of The Origin. Jablonka and Lamb's book makes the case for this much richer view of evolution by going both back to Darwin and forward to the latest findings of molecular and behavioural biology. What matters, they insist, is not genes per se but heritable variation - variations that are transmitted, by whatever means, from one generation to the next.
There are, they suggest, four levels at which such variation can occur. The first is unexceptional: the shuffling of DNA in sexual reproduction, which mixes variants from both parents, coupled with mutations - random changes in the DNA sequence. A second major source is not genetic but epigenetic - it depends on changes that occur in the "meaning" of given strands of DNA. Molecular biologists are discovering an increasing number of esoteric ways that DNA, or the proteins that surround it and ensure its orderly translation, are chemically modified during development. Such modifications, which profoundly alter how an organism develops, can, just like copies of DNA, be transmitted during reproduction, and in due course can feed back to modify the sequence of DNA itself.
A third dimension of evolution is one whose study Jablonka has made particularly her own - the inheritance of behavioural traditions. Rabbit mothers who feed on juniper berries transmit to their offspring a preference for such food, an inheritance stable across generations. In the days when milk was delivered in bottles to our doorsteps, blue tits learned to peck open the foil tops to drink the cream, a tradition acquired and passed on, by social learning, from generation to generation but now presumably lost because, in an environment of Tetra Paks, it is no longer an adaptive form of behaviour.
The authors' final dimension, a uniquely human one, is symbolic inheritance, the traditions we learn and pass on not by subtle odour-based cues in our mother's milk or faeces, or by direct imitation of our elders or peers, but through our capacity for language, and culture, our representations of how to behave, communicated by speech and writing.
The treatment of these higher levels is important, as the authors carefully distinguish their approach from the banalities of evolutionary psychology, of "memes", and even from Chomskyian ideas of universal grammar.
The slowest of all these forms of evolutionary change is that based on DNA, and there is a tendency to dismiss the others as all dependent "in the last analysis" on genes. Jablonka and Lamb vigorously rebut this. Rather, they insist, there are constant interactions between the levels - epigenetic, behavioural and even symbolic inheritance mechanisms also produce selection pressures on DNA-based inheritance and can, in some cases, even help direct DNA changes themselves - so "evolving evolution".
How does a species become fit to survive cosmic catastrophe, the extinction of the Sun, or catastrophic climate change?
If Darwinian natural selection is the mechanism or process by which the Earth becomes inhabited with the species most fit to survive, why are humans NOT the most fit to survive?
The quote above from "What Darwin Really Thought" includes the mention of "our capacity for language, and culture, our representations of how to behave, communicated by speech and writing" and "Chomskyian ideas of universal grammar", which are considerable issues:
Here there are some things that we can be pretty confident about. For one thing, it doesn’t appear that there’s any detectable variation among humans. They all seem to have the same capacity. There are individual differences, as there are with everything, but no real group differences—except maybe way at the margins. So that means, for example, if an infant from a Papua New Guinea tribe that hasn’t had contact with other humans for thirty thousand years comes to Boulder, Colorado, it will speak like any kid in Colorado, because all children have the same language capacity. And the converse is true. This is distinctly human. There is nothing remotely like it among other organisms. What explains this?(The Other Side of Noam Chomsky's Brilliant Mind). Another evolutionist, Ernst Mayr, has stated that human intelligence is a fatal mutation dooming the species:
In biology it was plausible quite recently to claim that organisms can vary virtually without limit and that each one has to be studied on its own. Nowadays that has changed so radically that serious biologists propose that there’s basically one multicellular animal—the “universal genome”—and that the genomes of all the multicellular animals that have developed since the Cambrian explosion half a billion years ago are just modifications of a single pattern. This thesis hasn’t been proven, but it is taken seriously.
I'LL BEGIN with an interesting debate that took place some years ago between Carl Sagan, the well-known astrophysicist, and Ernst Mayr, the grand old man of American biology. They were debating the possibility of finding intelligent life elsewhere in the universe. And Sagan, speaking from the point of view of an astrophysicist, pointed out that there are innumerable planets just like ours. There is no reason they shouldn't have developed intelligent life. Mayr, from the point of view of a biologist, argued that it's very unlikely that we'll find any. And his reason was, he said, we have exactly one example: Earth. So let's take a look at Earth. And what he basically argued is that intelligence is a kind of lethal mutation ... you're just not going to find intelligent life elsewhere, and you probably won't find it here for very long either because it's just a lethal mutation ... With the environmental crisis, we're now in a situation where we can decide whether Mayr was right or not. If nothing significant is done about it, and pretty quickly, then he will have been correct: human intelligence is indeed a lethal mutation. Maybe some humans will survive, but it will be scattered and nothing like a decent existence, and we'll take a lot of the rest of the living world along with us.(What Kind of Intelligence Is A Lethal Mutation?). There is little wonder then, that probably the most famous evolutionist now, next to Darwin, the uber dogmatic selfish gene guy Dawkins, is called an ass hole:
To put meat on the bones of his theory, James names names ... Rush Limbaugh and Michael Moore ... Richard Dawkins, Larry Summers, and Bernard-Henri Lévy ... Dick Cheney ... Ralph Nader ... There are many species in the asshole kingdom.(On the Origin of Assholes). It is time for science to grow up so that the lyrics by Buffalo Springfield no longer apply "hey children what's that sound, everybody look what's going down."
As a final comparison, let's look at the comments of two contemporary biologists, Jean-Baptiste Lamarck and Charles Darwin:
“One would say that [man] is destined to exterminate himself after having rendered the globe uninhabitable.” - Lamarck (1817)(Human evolution: Darwinism, by Jan Anthony Sapp, emphasis added). Dr. Sapp is a professor of the history of science.
[RE: Darwin:] In his private correspondence, [Darwin] wrote that “man in the distant future will be a far more perfect creature than he now is,” and that natural selection, driven by the struggle for existence between races, would continue to play a major role in human evolution. Darwin interpreted the Crusades in these terms. As he commented to his correspondent in 1881:
Lastly, I could show fight on natural selection having done and doing more for the progress of civilisation than you seem inclined to admit. Remember what risks nations of Europe ran, not so many centuries ago, of being overwhelmed by the Turks, and how ridiculous such an idea now is! The more civilized so-called Caucasian races have beaten the Turkish hollow in the struggle for existence. Looking to the world at no very distant date, what an endless number of the lower races will have been eliminated by the higher civilized races throughout the world.Darwin’s views were rooted in the erroneous concept of race of his time. Like the eugenicists who followed him early in the twentieth century, he failed to recognize the sizeable role of the environment, culture and education in establishing human characteristics.