Thomas S. Monson was only 36 when he was called to be an Apostle, and never since has one so young been called. He was 80 when he became prophet. He'd been in the First Presidency for the three previous prophets, so he was ready and prepared to take over.
First Presidency in 2008:
Thomas S. Monson
Henry B. Eyring
Dieter F. Uchtdorf
Quorum of the Twelve in 2008:
Boyd K. Packer, L. Tom Perry,
Russell M. Nelson, Dallin H. Oaks,
M. Russell Ballard, Joseph B. Wirthlin,
Richard G. Scott, Robert D. Hales,
Jeffrey R. Holland, David A. Bednar,
Quentin L. Cook...
Called to be Apostles by Thomas S. Monson:
D. Todd Christofferson, Neil L. Anderson
(January 24, 1945 - )
Apostle - April 5, 2008
Christofferson was born in American Fork, Utah, and lived most of his childhood in Utah Valley until his family moved to New Jersey. He served his mission in Argentina where Richard G. Scott was his mission president.
He got his bachelors from BYU and a JD from Duke. He clerked for Judge John J. Sirica during Watergate's hearings. He worked at law firms or as corporate counsel in a few different states.
He served as a bishop, stake president and regional representative before being called to the First Quorum of the Seventy. Right before he called to be an Apostle, he wrote an Ensign article about not just Apostles, but every member of the church has the capacity to stand as a witness for Christ.
He's been part of the effort to improve the church's relations with the LGBT community through Mormonsandgays.org. (His brother is gay.) He's one to watch.
(August 9, 1951 - )
Apostle - April 4, 2009
Andersen was born in Logan, Utah, and raised in Pocatello, Idaho. He served his mission in France. He got his bachelors from BYU and an MBA from Harvard Business School. He worked as a vice-president at a health-care business before returning to France as a mission president.
About a year after being released as mission president, he was called into the Seventy. He was in the Presidency of the Seventy when Joseph B. Wirthlin died, and Pres. Monson called Andersen to join the Q12. He's currently 63. He is the most recent Apostle to be called to the Q12.
General Conference is this weekend. Here's a look at the age-breakdown of the current Fifteen, including their seniority.
In Their 90's:
L. Tom Perry (92) - 3rd
Russell M. Nelson (90) - 4th
Boyd K. Packer (90) - 2nd
In Their 80's:
Thomas S. Monson (87) - 1st
M. Russell Ballard (85) - 6th
Richard G. Scott (85) - 7th
Dallin H. Oaks (82) - 5th
Robert D. Hales (82) - 8th
Henry B. Eyring (81) - 10th
In Their 70's:
Quentin L. Cook (74) - 13th
Dieter F. Uchtdorf (73) - 11th
Jeffrey R. Holland (73) - 9th
In Their 60's:
D. Todd Christofferson (69) - 14th
Neil L. Andersen (63) - 15th
David A. Bednar (62) - 12th