If the junior Thomas really was born in 1584/5, then our subject was more likely born ca. 1560, or earlier.

1.  John Camden Hotten, ed.  1874.  The Original Lists of Persons of Quality; Emigrants; Religious Exiles; Political Rebels; Serving Men Sold for a Term of Years; Apprentices; Children Stolen; Maidens Pressed; and Others Who Went from Great Britiain to the American Plantations, 1600-1700… from MSS Preserved in the state Paper Department of Her Majesty's Public Record Office, England. Chatto and Windus, London (reprinted 1974 and 1986 by Genealogical Publ. Co., Baltimore, MD; indexed on Broderbund CD-354; online at books.google.com and various other locations on the web; boldface added): 

The 1624/5 Muster List of Virginia is the first comprehensive census in British North America.  The list includes 1232 names, but does not include women and children.  The enumeration was taken between January 20th and February 7th 1624/5 [meaning 1624 by the calendar at the time and 1625 by our calendar, not that the year is uncertain].  There are numerous other references (books and web sites) providing the lists along with explanations and discussion.
pp. 201-265	MUSTERS OF THE INHABITANTS IN VIRGINIA.
p. 254	Elzabeth Cittie... CAPT THOMAS DAVIS his MUSTER Capt THOMAS DAVIS aged 40 in the John and Francis 1623 Thomas HEWES aged 40 in the John and Francis 1623 [one intervening household] PERCIVALL IBOTTSON his MUSTER PERCIVALL IBOTTSON aged 24 in the Neptune 1618 ELZABETH IBOTTSON aged 23 in the Flyinge Hart 1621 JOHN DAVIS aged 24 in the John and Francis 1623 Servants WILLIAM GREENE aged 28 in the Hopewill 1623 ROBART LOCKE aged 18 in the Warwicke 1621
If Thomas was age 40 in 1625, then he was born in 1584 or 1585, not 1590.  If John was age 24 in 1625, then he was born in 1600 or 1601, not 1599.  Other sources may trump these ages as censuses are not alway accurate as to age.  As far as I can tell, these three individuals — Capt. Thomas DAVIS, Thomas HEWES, and John DAVIS — are the only men from the voyage of the John and Francis in 1623 still alive and living in Virginia in 1625.

2.  Leslie Davis Dawson.  1984.  History of Dawson-Davis Family and Related Families of Fairfax and Prince William Counties, Virginia.  Rev. Ed. Plainfield, NJ. 406 pp. [ASIN: B00071AEKI; CS71.D272] (according to Amazon.com, this book is out of print as of 8 Dec 2016). Original edition 1974, 108 pp. [ASIN: B0006CGRFO].

3.  Email from descendant, Rev. Deborah DAVIS.