Rare But Not Of Concern

So, the whole sixth lum­bar ver­te­bra has kind of been of inter­est to me. I did some online search­ing and found an inter­est­ing arti­cle which explains the abnor­mal­i­ty some:

[A]pproximately 10% of adults, have a con­gen­i­tal anom­aly in their low­er back. One of the most com­mon anom­alies is the pres­ence of a sixth lum­bar ver­te­bra. Hav­ing one extra lum­bar ver­te­bra pro­vides no advan­tage or dis­ad­van­tage to the indi­vid­ual and is rarely a cause of back prob­lem­s… [A]nomalies such as these in the lum­bar spine and sacral spine are sim­ply vari­ants of nor­mal bony archi­tec­ture and are typ­i­cal­ly of no con­se­quence. In oth­er words, it would be very rare for an abnor­mal­i­ty such as a sixth lum­bar ver­te­bra or extra bone in the sacrum to cause back problems.

I’ll file this under “I found it on the inter­net so there­fore it must be true.” My doc­tor indi­cat­ed that mine was­n’t of con­cern since every­thing was all aligned. I did­n’t ask what hap­pens if it isn’t as I was afraid what the answer might be.

It would also appear that the cor­rect term for this “L6” bone is Lum­bosacral tran­si­tion­al ver­te­bra.

Now this com­ment was par­tic­u­lar­ly inter­est­ing to me:

You may be inter­est­ed to find that while the homo sapi­en is char­ac­ter­ized by hav­ing five lum­bar ver­te­bra but homo erec­tus (the first of the human skele­tons found in Africa, includ­ing Lucy and aus­tralo­p­ithe­cus africanus skele­tons) typ­i­cal­ly had 6 lum­bar vertebra.

Some­thing I was at least able to par­tial­ly cor­rob­o­rate here. Now, before you decide to start pok­ing fun at me for being less evolved than you, keep in mind that mod­ern great apes have only three or four lum­bar ver­te­brae. It’s all relative.