In 1993 he moved to the University of Missouri Columbia and the lab of Don Riddle,[5] discoverer of the gene daf-2 which controls lifespan, to work on C. elegans aging.
In collaborative work at UCL (2001-9), Gems contributed to showing that it does, in fruit flies[8] (with Linda Partridge) and in mice (with Dominic Withers).
This was developed by George C. Williams,[15] Mikhail Blagosklonny,[16] João Pedro de Magalhães[17] and Dr Carina Kern.
[18] Gems performed a series of studies suggesting that age-related disease in C. elegans were the result of programmatic changes, rather than molecular damage accumulation, traditionally viewed as a main cause of aging[19][20][21][22] Gems has been an outspoken critic of what he argues are ideas that are inadequate to guide research towards an understanding of the aging process.
[25] His recent work has increasingly involved developing new theories of aging that extend the programmatic theory, including the existence of programmed adaptive death in colonial organisms, perhaps including C. elegans;[26] the possibility that C. elegans exhibit reproductive suicide as seen in semelparous organisms such as Pacific salmon;[27][28] and a multifactorial model, based on the programmatic model, and earlier ideas from the Russian gerontologist Vladimir Dilman, to explain the origins of diseases of aging.