Skylark

Your dioxin exposure will most likely occur from combustion products. Everytime you fire up the backyard grill you create dioxins, though not enough to cause significant damage. Plasticizers such as bisphenol A and phthalates leach out of plastics into your food and drink all the time and is most likely what your friend was referring to. Of course, most of your exposure there is most likely to occur from that shower or bath you take every day.

How does the presence of one intelligent species affect the evolution of a second species towards intelligence? I think that man's intellectual development alters the selective pressures for intelligence in other species. I don't see another species gaining our level of intelligence on Earth mainly because we'll drive those candidate species to extinction or relegate them to small zoo populations.

Fishes that live in areas where anoxic conditions can occur often cannot obtain enough oxygen via gills and have accessory respiratory structures that enable them to breath air. The electric eel, in addition to gills, has an extensive series of highly vascularized papillae in the pharyngeal region. The eels rise to the surface to gulp air, which diffuses across the papillae into the blood. Other fishes swallow air and extract oxygen through vascularized regions of the gut. (Note that developmentally, lungs begin as evaginations of the gut.) Anabantid fishes (ex. bettas you see in pet stores) have vascularized chambers in the rear of the head, called labyrinths, which act in a similar manner. Many fishes are facultative air breathers; that is, oxygen uptake switches from gills to accessory organs when oxygen in the surrounding water becomes low. Others, like the electric eel and the anabantids, are obligatory air breathers. The gills alone cannot meet the respiratory needs of the fish even if the surrounding water is saturated with oxygen. These fishes drown if they cannot reach the surface to breath air.

For Daily Show clips I go to their website. As far as I can tell, if you watch all the clips you don't miss much of the show.

I enjoyed "The Genome War" by James Shreeve.

If you think of the role of DNA as solely to transmit genetic data, then I doubt a life form based on triple helix DNA would be that different if the triple helix could transmit the same amount of genetic data. I think the only difference between the double and triple helix would be in the energetic costs of DNA replication and translation. Presumably the triple helix would have a higher cost which would mean an organism using this type of DNA would need a higher metabolic rate to compensate. I would suspect this wouldn't make a dramatic change in the gross external morphology of the organism as warm-blooded tetrapods aren't that dramatically different from cold-blooded tetrapods relatively speaking even though their metabolic rates are many times greater.

Recent books that I've read, "Mind Wide Open" by Steven Johnson and "The Wisdom of Crowds" by James Surowiecki, may be of interest to you. Also I've heard good things about "Blink" by Malcolm Gladwell.

Triple helix DNA occurs when a third oligonucleotide sequence occupies the major groove of double-stranded DNA.