Archive: March, 2012
We’d leave them in the dust in the half marathon but they’d kill us on the uneven parallel bars. Scientists announced today they’d found fossil bones from an evolutionary cousin who would have co-existed with the diminutive 3.2 million-year-old Lucy. While Lucy walked like a human being, this new fossil's foot suggests it could walk upright but was more suited to the trees.
Lucy lived just about mid-way between the present day and the time our lineage split from that of chimpanzees. The new bones were dated at 3.4 million years old and were found just 30 miles from the site where Lucy's bones were excavated. The bones show enough humanlike traits to place it on our side of the chimp/human divide, but with an ape-like opposable toe that would have made walking more awkward and climbing trees more natural.
In last week’s issue of Science, a group of researchers from Harvard Medical School reported that mice raised with more bacteria were healthier than those raised in more sterile conditions. Bioethicist Art Caplan wrote up a nice summary of a paper here.
The scientists reached an admittedly geeky conclusion: “These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures,” they wrote in the journal Science. In other words, exposing baby mice to common germs got their immune systems appropriately busy and able to not over-react when encountering nasty bugs and other biological stuff later in life.
This is a big deal.
I’ve read that people are not well-equipped to intuitively grasp numbers in the billions. That’s why metaphors can be so helpful when dealing with the vast stretches of geologic time. One of my favorites is Carl Sagan’s cosmic calendar, into which the whole lifetime of the universe is compressed into a year. All of human history would take place in the last few seconds before midnight on December 31.
It makes sense to me to use human-scale analogies when attempting to explain and illuminate the vastness of time or other large numbers in nature. But what could be the point of taking mundane facts and blowing them up artificially so that large numbers can be invoked?
Last weekend, for example, an economist writing this op-ed for the Inquirer wrote that every penny increase in the price of gasoline costs American consumers $1.25 billion dollars a year. That sounds alarming, but is it? If we estimate there are 300 million people and at the very least 200 million are old enough to qualify as consumers, then the cost to each of them is about $6.25 a year, which doesn’t sound so terrible.
Sometimes evolution gives and sometimes it takes away. Cats have lost their ability to taste sweets, and dolphins lost the sensors needed to pick up bitter or sweet flavors.
From studying their DNA, scientists conclude that the common ancestor we share with these fellow mammals could taste all five of the major flavor types — sweet, salty, sour, bitter, and the more recently discovered savory flavor known as umami. But after we diverged, many lost some of their tasting ability.
Researchers from Monell Chemical Senses Center recently analyzed genetic material from 12 species of mammals, all of them meat eaters, and found that seven carried completely nonfunctional versions of the genes that endow us with an appreciation of sweets. Monell researchers had already shown this was the case with domestic cats. Now the scientists have found broken sweet genes in sea lions, fur seals, Asian otters, a cat relative called the linsang, and a mongoose relative, the fossa.
The latest chatter in the evolution blogosphere is brewing over an unlikely contention that Richard Dawkins is not an ape. Professor Dawkins says he’s an ape, which puts him in the same category as the rest of us human beings. A piece in the Washington Times contends that he’s not an ape and neither are other people who do crosswords and like Shakespeare.
Higgs has a theory he thinks explains both the Washington Times editorial and the more general problem with acceptance of evolution.
Higgs: While many people have written interesting blog posts here, here, here and here about the ape-hood of Richard Dawkins, I humbly suggest there's one more important point to be made. This episode has helped confirm my suspicion that you humans are embarrassed by your relatives. You don’t like other apes very much. You think they’re ugly and you imagine they’re smelly even though most of you have never sniffed a gorilla.
I’m reading a series of famous “Christmas” lectures by English physicist/chemist Michael Faraday. The year is 1860 and Faraday performed experiments that must have dazzled his audience with the magic of reality. In the course of dozens of fires, explosions, and other reactions, he demonstrated what’s really going on when a candle burns. He showed that the candle wax is vaporized, that the glow is from soot, and that a chemical reaction is taking place. He showed how to see the invisible in order to prove that the flame consumes oxygen and produced are carbon dioxide and water, and that these are compounds composed of the elements hydrogen, carbon and oxygen.
There was a quote I meant to underline, in which Faraday warned his audience that they should believe what they see for themselves over what they’re told. It’s driving me crazy that I can’t find it now, but it should resurface eventually. Faraday, while religious, was also something of a skeptic. He liked to investigate some of the popular paranormal ideas of his time – such as the notion that séances were summoning spirits.
I wonder what Faraday would say if he found out that a paper purporting to prove ESP was published in a reputable scientific journal in late 2010. The paper, by Cornell University psychologist Daryl Bem, was titled Feeling the Future: Experimental Evidence for Anomalous Retroactive Influences on Cognition and Affect, and appeared in The Journal of Personality and Social Psychology.
Several news items about animal behavior caught Higgs’ attention recently. He’s asked for a chance to comment:
Higgs: It never ceases to amaze me that humans focus so much energy looking for ways to set themselves apart from other animals. Some construct arguments to show that they’re more emotional than we are, or more altruistic and empathetic. Then sometimes the pendulum swings the other way and they talk about “evil” or “sin” as uniquely human capabilities. The issue came up this morning in a column by David Brooks that ran today the New York Times. It was called, When the Good Do Bad.
The column started with a reference to Robert Bales, the sergeant accused of killing 16 Afghan civilians after he “snapped.” Brooks quotes evolutionary psychologist David Buss, who has surveyed students and found that most had fantasized about killing other humans:
Here's the evolution column that ran in the Inquirer this morning:
By Faye Flam
INQUIRER STAFF WRITER