More Things that Don't Make Sense

New Scientist has a new feature on unexplained phenomena, "Thirteen More Things that Don't Make Sense." (Original set here.) Some of them actually do make sense, but they represent radical new discoveries. for example, the discovery that many organisms are genetic hybrids of distantly related species, especially in the sea:

LOOK at the genome of a sea squirt and you'll get a nasty surprise. Half of its genes have a straightforward evolutionary history. In fairness, so does the other half. Trouble is, the two histories are completely different. It seems that sea squirts do not, as we had thought, sit among the chordates, on the same evolutionary line as humans and other vertebrates. Instead, they are the result of what happens when you fuse an ancient chordate with the ancestor of a sea urchin.

One of the real puzzlers concerns sounds recorded by the US Navy's network of microphones on the sea floor, set up to track submarines. They have recorded sounds that resemble whale song but are a hundred times as loud, and other sounds that resemble nothing we know of.

The world is full of mystery, and many discoveries remain to be made.