Not So Identical

Apparently “identical” twins don’t even have identical genetics:

Identical twins emerge when a zygote — the fertilized egg that develops into an embryo — splits into two embryos. As such, they should have the same genomes. The researchers speculate that as the cells making up each embryo divide over and over again during development in the womb, mistakes occur as dividing cells shuffle copies of their DNA into daughter cells.

But genetic differences between identical twins might also accumulate after development over a twin’s life as well. “I think all our genomes are under constant change,” Bruder told LiveScience.

I think that this has implications for cloning as well. It may not be possible to exactly clone an individual, and the differences could turn out to be quite noticeable.

[Update in the evening]

Per some comments, the key point in this story is that it has long been known that there are differences in twins (personality, eyesight, fingerprints, etc.). But those are things that can arise even from an identical genome. The genes are not a blueprint, but rather a recipe, and even if a recipe is followed carefully, the results are not always guaranteed to be the same. The point of the article is that, contrary to previous theories that obvious differences in twins could be attributed solely to different environments, that the genome itself wasn’t necessarily the same. That is new.

Creating An Appearance Of An Appearance

Michael Kinsley has the best take so far on McCain and the New York Times:

I have come under some criticism for my criticism of the New York Times for its criticism of Sen. John McCain. Many readers of last week’s New York Times article about McCain, including me, read that article as suggesting that McCain may have had an affair with a lobbyist eight years ago. The Times, however, has made clear that its story was not about an affair with a lobbyist. Its story was about the possibility that eight years ago, aides to McCain had held meetings with McCain to warn him about the appearance that he might be having an affair with the lobbyist. This is obviously a much more important question. To be absolutely clear: The Times itself was not suggesting that there had been an affair or even that there had been the appearance of an affair. The Times was reporting that there was a time eight years ago when some people felt there might be the appearance of an affair, although others, apparently including McCain himself, apparently felt that there was no such appearance.

Read all.

Which Is Greener?

Driving, or walking? John Tierney stirs up a hornet’s nest of vegans and other morally overrighteous high-horse riders (see comments). I mean, to question Ed Begley, Jr. Isn’t that just the height of apostacy?

This reminds me of a piece that I’ve been thinking of writing about overall energy and fuel costs, including human fuel. With the ethanol boondoggle, we’ve gone back to the point at which we’re using crops for transportation (something we largely left behind at the end of the nineteenth century) and we now have increasing prices in both food and fuel as they compete with each other for the same farmland. This isn’t a good trend for the Third World (consider that one of the effects of the ethanol subsidies has been a dramatic increase in corn and tortilla costs in Mexico, making a poor country even more so).

The Quality Of Quantity

Via Geek Press, we have some interesting audio illusions over at The New Scientist. I found this one particularly so:

Some pieces of music consist of high-speed arpeggios or other repeating patterns, which change only subtly. If they’re played fast enough, the brain picks up on the occasional notes that change, and links them together to form a melody. The melody disappears if the piece is played slowly.

This is called an emergent property, and while many emergent properties arise from a critical mass (say, of the number of ants in a colony), they can also do so as a result of speed. Some AI researchers argue that human intelligence (and non-human as well) is in fact a result of simply having enough neurons (and at a higher level) various cognitive functions in one place to a degree that consciousness emerges. Others (such as Searle) scoff at the notion, arguing that gathering a large number of entities together isn’t going to change their properties in a qualitative way, and that’s simply common sense. You can’t combine a lot of dumb things and somehow get something smart. The whole may be greater than the sum of its parts, but not (so to speak) the sum of its (not so) smarts.

The argument against this is to point out another non-intuitive result. Prior to Maxwell, who would have imagined that you could wave a magnet back and forth and create color? Well, if you just wave it slowly, you won’t–all you’ll see is someone waving a magnet. But wiggle it half a quadrillion times per second, and suddenly there’s a electromagnetic wave that, when captured by the eye, causes one to (literally) see red. The auditory phenomenon described above is similar–play it too slowly and the music disappears, but speed it up, and a melody emerges.

Sore And Sunburned

Yeah, no posting today. Some long-time (over three decades) friends from Michigan were down for the weekend, and we went canoeing/kayaking today, seven miles round trip, on the south fork of the St. Lucie River, up in Stuart. I sunblocked my arms and upper portions, but forgot to do my legs. I’m just not used to wearing shorts, even in Florida.

I may post some pictures later, if after looking at them they seem worthwhile. We were a little disappointed at the wildlife. Only saw a couple gators, and no manatees. We saw several slider turtles though, and a sandhill crane walking through someone’s front (on the river side) yard. And no one fishing, which seemed a little surprising.

Biting Commentary about Infinity…and Beyond!