The bond between dog and man was forged at least 10,000 years ago; on that much, scientists can agree. But questions about precisely when and why dogs were domesticated remain unclear.
Did hunter-gatherers tiptoe into wolf dens, kidnap pups, and train them to guard and hunt? Or, was it a more opportunistic situation: Once people began to settle down and start farming and generating waste, did wolves learn to coexist peacefully with garbage dumps and the people that filled them with scraps?
A new study led by scientists at the Broad Institute, a genomics research center in Cambridge, and Uppsala University in Sweden tries to begin to answer the question by looking at the DNA of wolves and dogs, finding that key genetic changes affected dogs’ ability to eat a starch-rich diet, as well as their brain development.
The research, published Wednesday in the journal Nature, didn’t determine when those genetic changes occurred, or whether the digestive changes occurred at the same time as domestication. But the genetic differences provide new clues about what separates dogs from wolves, and may even implicate genes that changed as both humans and dogs shifted to a different diet — mutations that might underlie modern diseases, such as diabetes.
“It’s quite intuitive that one of the things that really changed with dogs was what they eat; wolves are carnivores, and dogs are omnivores, eating everything like we do,” said Kerstin Lindblad-Toh, director of vertebrate genome biology at the Broad Institute and Uppsala University and the senior author of the study.
The reason the genes might be interesting ways to probe disease, including human disease, is a bit subtler.
The researchers see the 36 regions of the genome that popped out as different between dogs and wolves as areas that may have been changed as wolves adapted to a human lifestyle.
Those areas might provide hints about the genes and biological underpinnings of modern diseases that have arisen with the shift from a peripatetic existence to a grain-based diet and life in settlements.
Scientific gullibility sparks wild Neanderthal cloning rumor
Harvard Medical School genetics professor George Church found himself at the middle of a viral Internet kerfuffle last week. Blogs and news websites picked up on an interview in the German publication, Der Spiegel, and distorted his speculative comments about the technological feasibility of cloning a Neanderthal to suggest the scientist was looking for volunteers: “Wanted: ‘Adventurous woman’ to give birth to Neanderthal man - Harvard professor seeks mother for cloned cave baby,” the Daily Mail newspaper in the United Kingdom announced.
The interview, if one bothers to read it, is prototypically Church: It unflinchingly looks toward the technology of the future, taking an optimistic and expansive view of what will one day be possible. The discussion unfolds like a thought experiment, with Church considering the ethical, social, and regulatory issues that could arise from recreating Neanderthals or building new life forms.
In a phone interview last week, Church noted that he is not working on sequencing Neanderthal DNA. He is not synthesizing it. He is not working on cloning any whole organisms. He said the pickup of the news story and the subsequent headline creep online has been instructive and made him concerned about the level of basic science literacy, in comparison with other spheres of society.
“When you see how gullible people were on this particular incident, I wonder,” Church said. “If we really talked about [science] as much as we talk about other things,” would this same thing have happened?
Church is willing to talk and think big, which is partly why he has been so successful as a scientist, and also part of what made his comments so ripe to be taken out of context. He has seen massive scientific change during his career, helping enable a downward spiral in the cost of sequencing DNA, from about $3 billion to $3,000 for an entire human genome. “So I have a tendency to think in increments bigger than I, say, would have when I was younger,” Church said.
He sees communication with the public as a major part of his job, and said that he does not think this incident will cause him to shy away from talking openly about the future trajectory of science. Greater understanding of science, he hopes, will mean a less credulous audience.
Much of the reaction has been supportive. More than 100 people have e-mailed him, volunteering for the job of being surrogate to the first cloned Neanderthal. But, as they could have found out by reading his interview, that job isn’t open — in his lab, or anyone else’s.
In bird evolution, robins deserve new look, expert urges
What could be a more ordinary sight than the robin, the red-breasted bird that hops around on the ground, yanking worms out of the dirt? Go out with a bunch of birdwatchers on a cold day near dawn and you’ll hear a sigh of disappointment when a bird in the distance turns out to be a boring old robin.
But Arkhat Abzhanov, associate professor of organismic and evolutionary biology at Harvard University, wonders: Have you ever really looked at a robin? What shape is its beak? What about its head?
Abzhanov, who studies the evolution of birds, sees the 10,000 species that fill our world — including some of the most ordinary ones — as a major opportunity to investigate deep questions about both evolution and developmental biology.
“What I think is the most interesting thing about birds is we see them everyday and we’re so used to them,” he said. “ And very few people realize just how unusual these animals are.”
Take the beak: It’s easy to think of it as a primitive triangular appendage that opens and closes; a standard part that can be penciled into a child’s drawing. But Abzhanov calls it “the ultimate tool” and a source of amazing diversity and specialization in the bird world, from pelicans to finches.
Abzhanov plans to both demystify bird biology and conjure a bit of mystery about the ones we take for granted, at a talk called “What art thou, little bird?” at the Harvard Museum of Natural History on Thursday, Jan. 31 at 6 p.m.