The Trouble with Darwin
Like many others, I watched the recent debate between Bill Nye and Ken Ham with a queer mixture of awe and déjà vu. Who knew that 89 years later, we’d still be litigating the Scopes trial? As someone trained in the sciences, I find it horrifying that there are college-educated people in the U.S. (and around the world) who believe the earth is 6,000 years old; and yet at the same time, I have a certain amount of discomfort, myself, with evolutionary theory—not because it demeans the nobility of man or denies the Bible, or anything of that sort, but because it’s such an incomplete and unsatisfying theory on purely scientific grounds. (Many physicists feel much the same way about quantum theory.)
It always amazes me that creationists do so litte research on Darwinism before attacking it. Darwin’s theory is subject to some very legitimate scientific criticisms. Biologists are, by and large, painfully aware of the theory’s shortcomings.
Darwin’s landmark work was called The Origin of Species, yet it doesn’t actually explain in detail how speciation happens (and in fact, no one has seen it happen in the laboratory, unless you want to count plant hybridization or certain breeding anomalies in fruit flies). Almost everything in evolutionary theory is based on “survival of the fittest,” a tautology that explains nothing. (“Fittest” means most able to survive. Survival of the fittest means survival of those who survive.) The means by which new survival skills emerge is, at best, murky. Of course, we can’t expect Darwin himself to have proposed detailed genetic or epigenetic causes for speciation, given that he was unaware of the work of Mendel, but the fact is, even today we have a hard time figuring out how things like a bacterial flagellum first appeared.
When I was in school, we were taught that mutations in DNA are the driving force behind evolution, an idea that is now thoroughly discredited. The overwhelming majority of non-neutral mutations are deleterious (reducing, not increasing, survival). This is easily demonstrated in the lab. Most mutations lead to loss of function, not gain of function. Evolutionary theory, it turns out, is great at explaining things like the loss of eyesight, over time, by cave-dwelling creatures. It’s terrible at explaining gain of function.
It’s also terrible at explaining the speed at which speciation occurs. (Of course, The Origin of Species is entirely silent on the subject of how life arose from abiotic conditions in the first place.) It doesn’t explain the Cambrian Explosion, for example, or the sudden appearance of intelligence in hominids, or the rapid recovery (and net expansion) of the biosphere in the wake of at least five super-massive extinction events in the most recent 15% of Earth’s existence.
Of course, the fact that classical evolutionary theory doesn’t explain these sorts of things doesn’t mean we should abandon the entire theory. There’s a difference between a theory being wrong and being incomplete. In science, we cling to incomplete theories all the time. Especially when the alternative is complete ignorance.
Neanderthals made beneficial contributions to the genomes of many modern
Artist's impression by S. Plailly/E. Daynes/SPL
Modern Human Genomes Reveal Our Inner Neanderthal
Sex with Neanderthals had its ups and its downs. Cross-breeding may have given modern humans genes useful for coping with climates colder than Africa’s, but the hybrid offspring probably suffered from significant fertility problems.
Those conclusions come from two papers published today in Science and Nature, which identify the slices of the genome that contemporary humans inherited from Neanderthals, the stocky hunter-gatherers that went extinct around 30,000 years ago.
Homo sapiens and Neanderthals share a common ancestor that probably lived in Africa more than half a million years ago. The ancestors of Neanderthals were the first to move to Europe and Asia while the modern-human lineage stayed in Africa. But after modern humans began to leave Africa less than 100,000 years ago, they interbred with the Neanderthals who had settled on a range stretching from Western Europe to Siberia.
“These were bits of the genomes that had not seen each other for half a million years,” says David Reich, a population geneticist at Harvard Medical School in Boston, Massachusetts, who led the Nature study along with colleague Sriram Sankararaman. “That’s something that doesn’t happen in human populations today.”
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Engineer Converts Yeast Cells Into ‘Sweet Crude’ Biofuel
Jan. 22, 2014 — Researchers at The University of Texas at Austin’s Cockrell School of Engineering have developed a new source of renewable energy, a biofuel, from genetically engineered yeast cells and ordinary table sugar. This yeast produces oils and fats, known as lipids, that can be used in place of petroleum-derived products.
Humanity’s Most Common Male Ancestor Emerged Earlier Than Thought: 209,000 Years Ago, Study Finds
Jan. 22, 2014 — Our most common male ancestor emerged some 209,000 years ago — earlier than many scientists previously thought, according to new research from the University of Sheffield.
The pioneering study, conducted by Dr Eran Elhaik from the University of Sheffield and Dr Dan Graur from the University of Houston, also debunked the discovery of the Y chromosome that supposedly predated humanity.
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‘Ardi’ Skull Reveals Links to Human Lineage
Jan. 6, 2014 — One of the most hotly debated issues in current human origins research focuses on how the 4.4 million-year-old African species Ardipithecus ramidus is related to the human lineage. “Ardi” was an unusual primate. Though it possessed a tiny brain and a grasping big toe used for clambering in the trees, it had small, humanlike canine teeth and an upper pelvis modified for bipedal walking on the ground.Scientists disagree about where this mixture of features positions Ardipithecus ramidus on the tree of human and ape relationships. Was Ardi an ape with a few humanlike features retained from an ancestor near in time (between 6 and 8 million years ago, according to DNA evidence) to the split between the chimpanzee and human lines? Or was it a true relative of the human line that had yet to shed many signs of its remote tree-dwelling ancestry?
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