9 December 2010 early AM

Sleep was better than 2 nights ago but not as good as last night. I think that I need to drink more water.

Science
This is an interesting article on how civilizations changed with respect to changing climates:

John Roach writes:Our climate is changing and humans are certainly part of the reason why, according to most climate scientists. Will the changes in the climate force us to change how we live?

Probably, if the past is any guide to the future. At least that’s the implication to be drawn from a newly published study that found a tight relationship between changes in the climate and human cultures in ancient North America.

The study’s authors, from the University of Ottawa, explain that archaeologists divide the chronology of prehistoric North America into three main phases: Paleoindian, Archaic and Woodland. Each period is defined by lifestyle changes that broadly show a move towards more sedentary lifestyles, along with shifts in the types of plants and animals they ate.

To see how tight the connection is between climate and cultural change, the researchers examined a database of radiocarbon-dated archaeological artifacts as well as records and reconstructions of the ancient climate in the northeastern United States. The team found that “with the exception of the transitions into the Middle and Late Woodland periods, the latter of which denotes the adoption of maize agriculture, every cultural transition corresponds to a major transition in the climate and vegetation of the region.”
[...]
Alex Chepstow-Lusty is a researcher in paleoecology at the Center for Bio-archaeology at the University of Montpellier 2 in France who has studied the connections between climate and cultural change in South America. He said the new study shows convincing connections between climate and culture, but he urged caution in interpreting the results.

“Correspondence does not always mean causation and the cultural response is driven by a myriad of socio-economic factors as well –- though somewhere in the mix are environmental drivers,” he told me in an e-mail.”Separating out these factors is often not possible.”

Note the caveat. That is what is interesting in the internet age; people get their work out very quickly and it often gets circulated before the scientific community as a whole gets a chance to completely vet it (beyond the usual peer review process). This “arsenic based life-form fiasco” claim was an example of that.

We see another possible example of that here: there was a widely circulated claim that there was evidence of a “periodic universe” that came in cycles (possibly big bangs/big crunches repeated over and over). Many top scientists are skeptical that there IS such evidence; in fact finding patterns where no pattern really exists is common. That doesn’t mean that this claim is wrong; it is just that there isn’t yet clear and convincing evidence that it is true and many interesting, reasonable conjectures turn out to be false.

Evolution
Jerry Coyne has an interesting article about speciation. His summary (for non-experts such as myself) isn’t hard to read but it is hard to summarize in a paragraph. But I’ll try: roughly, a species is a collection of living beings for which gene flow (via reproduction) is possible. New species from when groups form for which gene flow is impossible (e. g., red squirrels and gray squirrels). This often happens when groups become isolated.
Things get interested when there has been some drift between the species and then they get back together AND they are at a state when, say, mating produces some sterile hybrids and some non-sterile hybrids.
The interesting part: it appears that in such a situation, there is some evolutionary advantage (in terms of being able to pass genes along) to species becoming more selective in their mating and mating with members of the group for which the offspring is more likely to be non-sterile.
Anyway, read the article; it is fun.

Here is another article from Why Evolution Is True You’ve seen the pictures of the various embryos of animals and how similar they look. You’ve also seen how similar they look in the “middle” stage. What is going on there? It turns out that it is in the middle stage that the older genes (older in terms of “on the evolutionary tree”) get expressed. Read Matthew Cobb’s article on this; it too is a treat!

Science in Politics Today’s Republican party does have a large anti-intellectual wing in it; some of it might well be driven by religious or economic interests.

But there may be something else going on. You’ve seen the attacks on Al Gore? Well, there is a school of thought that some Republicans are attacking the existence of global climate change in an effort (or knee jerk reaction) to discredit Al Gore, who is popular in leftist circles.

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