5

As med­i­cal and po­lit­i­cal sci­ence ad­vanced in tan­dem over the cen­turies, pe­ri­od­ic at­tempts to al­le­vi­ate block­ages of this type were made.  Traces in the fos­sil record from as re­cent as 2006 pro­vide fur­ther con­fir­ma­tion.