genome

Pretty much everyone knows that oxygen is a fundamental requirement for life as we know it, but oddly enough that’s not entirely right. There are many simple life forms, such as some kinds of bacteria and archea, that don’t have a major metabolic pathway that needs oxygen.

At one Stone-Age-era archaeological site in southern Denmark on the island Lolland all of the artifacts have been sealed in mud since the Mesolithic period 6,000 years ago. One artifact is what researchers are calling an early version of chewing gum, made from birch pitch that oozed from birch bark after being heated.