The Calverleys (and verified descendants) are I-M253: https://www.familytreedna.com/public/Caverly%20Family%20DNA%20Proje...
The Calverts (Lords Baltimore subset) are R-P312: https://www.familytreedna.com/public/Calvert_Genealogy-DNA_Reposito...
Hard copy documentation, such as it is agrees: Walter Calverley did not have a son Alan. http://boards.ancestry.com/thread.aspx?mv=flat&m=49&p=surna...
QED?
There is a whole *book* of "The Calverely Charters Presented to the British Museum", By Sir Walter Calverley Trevelyan.
Of particular relevance here is the charter on pp. 251-253, covering detailed arrangements between Sir John Tempest, knight and Walter Calverley, esq., for the marriage of Sir John's daughter Agnes to Walter's son and heir William.
Also mentioned are Walter's wife Elizabeth; his (late) father Sir Walter Calverley; his other sons Thomas and Robert; and various contingencies depending on who should die before whom. The date is given in the form "vii January Henry Sext xx", which translates to 7 January 1442.
Here's the list that familytreedna has collected in the "Calvert (and variants)" group: https://www.familytreedna.com/public/Calvert_Genealogy-DNA_Reposito...
Most of the findings are relatively recent due to difficulties establishing paper trails.
The Calverley group at FT/DNA is included on the Calvert page because of individual claims that it was Calvert. They have not separated off to their own distinct project nor, apparently, joined another existing project. Walter Calverley is definitely not a Calvert. -- David Bell - Admin, the Calvert surname project at familytreedna and the Calvert Research group at facebook.