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Guinea pigs are practically synonymous with experiments. Lab rats have become the workhorses of modern medicine. Genetics owes a huge debt to the humble fruit fly. There's almost no branch of the life sciences, in fact, that hasn't leaned heavily on one animal or another.
Sam Kean -
Most mutations involve typos: Something bumps a cell's elbow as it's copying DNA, and the wrong letter appears in a triplet - CAG becomes CCG.
Sam Kean
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All human beings are, in fact, born with dozens of mutations their parents lacked, and a few of those mutations could well be lethal if we didn't have two copies of every gene, so one can pick up the slack if the other malfunctions.
Sam Kean -
Atoms of Element 118 fill an outer shell with electrons, creating a special type of element called a noble gas. Noble gases are natural turning points on the table, ending one row and pointing to the next.
Sam Kean -
Our evolution could have gone in different directions a lot of times. We could have gone extinct at some points. We might not have gotten our big brains, or Neanderthals might have made it while we did not.
Sam Kean -
Scientists didn't discover the noble gas helium - the second most common element in the universe - on Earth until 1895. And they thought it existed in minute quantities only, until miners found a huge underground cache in Kansas in 1903.
Sam Kean -
The idea of critical windows extends beyond just vision, of course: almost every system in the brain has a critical window when it needs to experience certain stimuli, or it won't get wired up properly. The most obvious example is language: if you don't learn a language early on, it's nigh impossible to become truly fluent.
Sam Kean -
One theme I ran into over and over while writing about the periodic table was the future of energy and the question of which element or elements will replace carbon as king.
Sam Kean
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Some scientists claim - although these claims are contentious - that they can form deadly isomers with simple X-rays and that hafnium can multiply the power of these X-rays to an astounding degree, converting them into gamma rays up to 250 times more potent than the X-rays.
Sam Kean -
Aluminum is the most common metal in the earth's crust, almost twice as abundant as iron. And one common class of aluminum minerals, collectively called alum, has been in use since at least Greek and Roman times.
Sam Kean -
When it comes to the periodic table, the United States really blew its chance to make a name for itself. If you look over a map of all the elements named for cities, states, countries, and continents, it's not surprising that European locales dominate the map.
Sam Kean -
There are a few elements - especially platinum and palladium - that have the amazing ability to absorb up to 900 times their own volume in hydrogen gas. To get a sense of the scale there, that's roughly equivalent to a 250-pound man swallowing something the size of a dozen African bull elephants and not gaining an inch on his waistline.
Sam Kean -
Every glass thermometer has subtle variations in the size and shape of the bulb at the bottom and the capillary tube inside, as well as variations in the width of gradations on the side. The compounded effect of these uncertainties is that each thermometer reads temperature slightly differently.
Sam Kean -
Things look especially bleak for common killers such as diabetes and heart disease. Those ailments clearly have a genetic component. But when scientists survey genes looking for which mutations patients have in common, they come up empty.
Sam Kean
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If you had to sum up chemistry in one sentence, it might be this: Atoms need to have full shells of electrons to feel satisfied, and different elements steal, shed, or borrow different numbers of electrons to achieve a full shell.
Sam Kean -
In some sense, what you might have suspected from the first day of high-school chemistry is true: The periodic table is a colossal waste of time. Nine out of every 10 atoms in the universe are hydrogen, the first element and the major constituent of stars. The other 10 percent of all atoms are helium.
Sam Kean -
X-rays revealed that some people were born without a corpus callosum, and they seemed just fine.
Sam Kean -
Except for certain moments - when cells are dividing, for instance - chromosomes don't form compact, countable bodies inside cells. Instead, they unravel and flop about, which makes counting chromosomes a bit like counting strands of ramen in a bowl.
Sam Kean -
Although it's the hub of the nervous system and the ultimate terminus of every nerve, the brain itself lacks enervation and therefore cannot feel pain.
Sam Kean -
Your body thinks radium is a great thing to pack into bone - where it kills some cells outright and scrambles the DNA of others, causing problems like cancer.
Sam Kean
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To be sure, ASPM isn't the gene responsible for building big brains - there's no such single gene. But it's critical to the process, and the primate line has almost certainly benefited from distinct changes in ASPM.
Sam Kean -
Carbon's eastern neighbor on the table, nitrogen, dresses up diamonds in pinks, yellows, oranges, and brownish tints known romantically as 'champagne.'
Sam Kean -
Whereas recessive traits require two bad copies of a gene to become noticeable, a dominant trait expresses itself no matter what the other copy does. A benign example of dominance: If you inherit one gene for sticky wet earwax and one gene for dry earwax, the sticky earwax gene wins out every time.
Sam Kean -
I'm kind of a sucker for the retro-diagnoses.
Sam Kean