I still say some of the best programming is on public educational TV.  This week, Nova looks at the so-called "family that walks on all fours".  If you haven’t heard about them, it’s an interesting story.

The Ulas family lives in a remote village in Turkey.  They are nineteen in all (it is a big family) which is unique in and of itself.  But what makes this family Nova-worthy is the fact that five of the siblings — four sisters and one brother — walk on all fours; that is, with their feet and the palms of their hands.  They are known as "handwalkers".

No, they’re not eccentric.  Like dogs or other mammals, they simply cannot maintain their balance on the legs.  In their cases, it is due to a rare genetic brain disorder — a form of retardation that effects their ability to stand.  So they became quadropeds instead of bipeds.

They are of special interest to evolutionary scientists.  After all, our ape ancestors made the transition from walking on all fours to walking on two legs.  It is thought that these five "handwalkers" may be a rare example of "reverse evolution" — i.e., the part of the brain that developed late in human evolution (the part which allows us to stand) simply went missing in these people.

Anyway, the Nova special airs this week.