Question: What clan, hailing from a 13th century tower house, did Alexander Fraser of Touchfraser and Cowie descend from?

Context paragraphs:
Alexander Fraser of Touchfraser and Cowie: Alexander Fraser of Touchfraser and Cowie (died 11 August 1332) was a member of the Scottish nobility who served as the Lord Chamberlain of Scotland and also as the Sheriff of Stirling and Sheriff of Kincardine.  He was a descendant of the Clan Fraser members deriving from Oliver Castle.  Alexander died at the Battle of Dupplin Moor.

Auchterhouse Castle: Auchterhouse Castle is a c. 13th century castle located northwest of Dundee, Angus, Scotland.  The original castle was enclosed with walls, towers, and contained a keep.  The castle may have been in ownership of the Ramsay family, who were hereditary Sheriffs of Angus.  Sir William Wallace is alleged to have stayed at the castle and one its towers was named in his honour.  King Edward I of England spent the night of the 20 July 1303 at the castle.  The castle came into the possession of James Erskine, 7th Earl of Buchan who may have built the 17th century tower house.

Protestant church of Drogeham: The Protestant church of Drogeham or Saint Nicholas church is a church in Drogeham, Netherlands.  The current church was built in 1876 on the site of an older church build in the 13th century.  The church is built against the 13th century tower of the old church and on top of the tower it is a gable roof.  The old church was a Roman Catholic church dedicated to Saint Nicholas but became a Protestant church after the Protestant Reformation.

Clan Fraser of Lovat: Clan Fraser of Lovat (Scottish Gaelic: "Friseal" ] , French: "Clan Fraiser" ) is a Highland Scottish clan.  The Clan Fraser of Lovat has been strongly associated with Inverness and the surrounding area since the Clan's founder gained lands there in the 13th century, but Lovat is in fact a junior branch of the Clan Fraser who were based in the Aberdeenshire area.  Both the Clan Fraser and the Clan Fraser of Lovat have their own separate clan chiefs who are recognized by the Lord Lyon King of Arms under Scottish law.  The Clan Fraser of Lovat in Inverness-shire has historically dominated local politics and been active in every major military conflict involving Scotland.  It has also played a considerable role in most major political turmoils.  'Fraser' remains the most prominent family name within the Inverness area.

Duddo Tower: Duddo Tower is a Scheduled Ancient Monument and a Grade II listed building comprising the ruinous remains of an ancient pele tower and 16th century tower house, situated on a prominence on the south side of the village of Duddo, Northumberland, England.

Borve Castle, Benbecula: Borve Castle, also known as Castle Wearie, and Caisteal Bhuirgh in Scottish Gaelic, is a ruined 14th century tower house, located at the south-west of the island of Benbecula, in the Western Isles of Scotland.  MacGibbon and Ross attributed the building of the tower to Amie mac Ruari, wife of John of Islay, and dated it to between 1344 and 1363.  It was occupied by the Macdonalds of Benbecula until the early 17th century.

Oliver Castle: Oliver Castle was a medieval tower house, located in the upper Tweed Valley in the Scottish Borders.  The site of the hillfort known as Oliver Castle is to the north of the village of Tweedsmuir, although the site of the tower house is less certain.  Mentioned in a document of c.1200, it was originally part of the line of peel towers along the Tweed Valley.  It was replaced in the seventeenth century by a house, which was itself replaced in the late 18th century by the present Oliver House.  For most of its existence the property has been owned by members of the Tweedie family.

Clan MacNeil: Clan MacNeil, also known in Scotland as Clan Niall, is a highland Scottish clan, particularly associated with the Outer Hebridean island of Barra.  The early history of Clan MacNeil is obscure, however despite this the clan claims to descend from the legendary Irish King Niall of the nine hostages.  The clan itself takes its name from a "Niall" who lived in the 13th or early 14th century, and who belonged to the same dynastic family of Cowal and Knapdale as the ancestors of the Lamonts, MacEwens of Otter, Maclachlans, and the MacSweens.  While the clan is centred in Barra in the Outer Hebrides, there is a branch of the clan in Argyll (McNeill/MacNeill) that some historians have speculated was more senior in line, or possibly even unrelated.  However, according to Scots law the current chief of Clan Macneil is the chief of all MacNeil(l)s.

Frasers of Philorth: The Frasers of Philorth are a Scottish lowland family, originally from the Anjou region of France.  Their family seat is in Sauchen, Aberdeenshire, Scotland.  Since the time of Alexander Fraser, 11th Lord Saltoun, the heads of the Philorth family are the Lords Saltoun.  The current head of the Frasers of Philorth is Flora Fraser, 21st Lady Saltoun who is Chief of the Name and Arms of Clan Fraser since 1 May 1984, by decree of the Court of the Lord Lyon.  The family's arms are ""azure, three cinquefoils argent""—three silver strawberry flowers on a field of blue.  The heraldic cinquefoil is a stylized five-point leaf; the cinquefoils which appear the Fraser of Philorth coat-of-arms are specifically strawberry flowers.  Only the Lady or Lord Saltoun is permitted to display these arms plain and undifferenced.

Barony of Cowie: The Barony of Cowie is a geographical and political division of land in Aberdeenshire, Scotland deriving from the Middle Ages.  King Robert the Bruce conferred these lands of the Barony of Cowie, along with the Barony of Cluny and the Barony of Kinnaird upon Alexander Fraser of Touchfraser and Cowie, who was his Chamberlain at least as late as 1319 AD.  The major transport route across the Barony of Cowie in the Middle Ages was an ancient trackway known as the Elsick Mounth,

Supporting paragraphs: Alexander Fraser of Touchfraser and Cowie Oliver Castle
Answer: Clan Fraser