Has it ever struck you … that life is all memory, except for the one present moment that goes by you so quickly you hardly catch it going? It’s really all memory … except for each passing moment. — Eric Kandel, “In Search of Memory: The Emergence of a New Science of Mind” (via neuromorphogenesis)
Taller, Fatter, Older: How Humans Have Changed in 100 Years
Humans are getting taller; they’re also fatter than ever and live longer than at any time in history. And all of these changes have occurred in the past 100 years, scientists say. So is evolution via natural selection at play here? Not in the sense of actual genetic changes, as one century is not enough time for such changes to occur, according to researchers. Most of the transformations that occur within such a short time period “are simply the developmental responses of organisms to changed conditions,” such as differences in nutrition, food distribution, health care and hygiene practices, said Stephen Stearns, a professor of ecology and evolutionary biology at Yale University. [10 Things That Make Humans Special] But the origin of these changes may be much deeper and more complex than that, said Stearns, pointing to a study finding that British soldiers have shot up in height in the past century. “Evolution has shaped the developmental program that can respond flexibly to changes in the environment,” Stearns said. “So when you look at that change the British army recruits went through over about a 100-year period, that was shaped by the evolutionary past.” And though it may seem that natural selection does not affect humans the way it did thousands of years ago, such evolutionary mechanisms still play a role in shaping humans as a species, Stearns said. “A big take-home point of all current studies of human evolution is that culture, particularly in the form of medicine, but also in the form of urbanization and technological support, clean air and clean water, is changing selection pressures on humans,” Stearns told Live Science. “When you look at what happens when the Taliban denies the polio vaccination in Pakistan, that is actually exerting a selection pressure that is different in Pakistan than we have in New York City,” he said. Here’s a look at some of the major changes to humans that have occurred in the past century or so. (via Taller, Fatter, Older: How Humans Have Changed in 100 Years)
Google has started to collect medical data from volunteers as part of an ambitious project designed to build a database of records that show what a healthy human being should be. The project, developed by Google’s experimental Google X wing and called Baseline Study, sees the company first harvesting anonymous genetic and molecular information from 175 people. According to The Wall Street Journal, Baseline Study will soon draw information from thousands more in a bid to create a picture of a person in perfect health.
The project is designed to pull together a huge amount of data that will not only allow medical professionals to detect and treat major health issues such as heart disease and cancer earlier, but will also enable them to detect trends and patterns in human health, making medicine more about the prevention of illness than the cure.
Project Baseline will use Google’s computational power to identify “biomarkers” in the data that could help people stave off or avoid health issues. Medical science has traditionally discovered biomarkers for late stage diseases, but it’s Google’s hope that Project Baseline will also be able to crunch through data to detect tendencies in our bodies that can be addressed before they become life-threatening.
Dr. Conrad posits an example where the data allows researchers to pick out a biomarker that shows some people can break down fatty foods efficiently. Others, he suggests, may lack the marker, putting them at risk from heart disease. By identifying such trends before the disease has become too severe and treatment is necessary, Project Baseline’s information could suggest people change their behavior before their first heart attack, or enable scientists to develop something to help at-risk people break down fatty foods.
Already Google has clarified the medical data it receives will be anonymous by the time it gets its hands on it, and specified that such information would not be shared with insurance firms. — Google is collecting medical data to paint a picture of perfect human health | The Verge
More than 90% of human DNA is doing nothing very useful, and large stretches may be no more than biological baggage that has built up over years of evolution, Oxford researchers claim. The scientists arrived at the figure after comparing the human genome with the genetic makeup of other mammals, ranging from dogs and mice to rhinos and horses. The researchers looked for sections of DNA that humans shared with the other animals, which split from our lineage at different points in history. When DNA is shared and conserved across species, it suggests that it does something valuable. Gerton Lunter, a senior scientist on the team, said that based on the comparisons, 8.2% of human DNA was “functional”, meaning that it played an important enough role to be conserved by evolution. “Scientifically speaking, we have no evidence that 92% of our genome is contributing to our biology at all,” Lunter told the Guardian. Researchers have known for some time that only 1% of human DNA is held in genes that are used to make crucial proteins to keep cells – and bodies – alive and healthy. The latest study, reported in the journal Plos Genetics, suggests that a further 7% of human DNA is equally vital, regulating where, when, and how genes are expressed. But if much of our DNA is so worthless, why do we still carry it around? “It’s not true that nature is parsimonious in terms of needing a small genome. Wheat has a much larger genome than we do,” Lunter said. “We haven’t been designed. We’ve evolved and that’s a messy process. This other DNA really is just filler. It’s not garbage. It might come in useful one day. But it’s not a burden.”
Some of our DNA is left over from ancient viruses that inserted their genetic material into our DNA – or our ancestors DNA – and got mutated to pieces over millennia of evolution. Some still have the ability to jump around in our genomes, adding to the filler as they do so, but are so crippled they cannot break out.
Though 8.2% seems a small portion of DNA to call functional, the meaning of the word is very specific. In the Oxford study, DNA is “functional” if it affects our reproductive fitness.
But other scientists take a broader view of what it means for DNA to be functional. Most of the 92% that Lunter’s group says is not functional DNA is still active in some way in the body. — Less than 10% of human DNA has functional role, claim scientists | Science | The Guardian
Elephants possess a sense of smell that is likely the strongest ever identified in a single species, according to a study by Japanese scientists out Tuesday. The African elephant’s genome contains the largest number of olfactory receptor (OR) genes—nearly 2,000—said the study in the journal Genome Research. Olfactory receptors detect odors in the environment. That means elephants’ sniffers are five times more powerful than people’s noses, twice that of dogs, and even stronger than the previous known record-holder in the animal kingdom: rats. “Apparently, an elephant’s nose is not only long but also superior,” said lead study author Yoshihito Niimura of the University of Tokyo. — Elephants possess ‘superior’ sense of smell, study finds