  Understanding the evolution of galaxies provides crucial insights into a
broad range of aspects in astrophysics, including structure formation and
growth, the nature of dark energy and dark matter, baryonic physics, and more.
It is, however, infeasible to track the evolutionary processes of individual
galaxies in real time given their long timescales. As a result, galaxy
evolution analyses have been mostly based on ensembles of galaxies that are
supposed to be from the same population according to usually basic and crude
observational criteria. We propose a new strategy of evaluating the evolution
of an individual galaxy by identifying its descendant galaxies as guided by
cosmological simulations. As a proof of concept, we examined the evolution of
the total mass distribution of a target strong lensing galaxy at $z=0.884$
using the proposed strategy. We selected 158 galaxies from the IllustrisTNG300
simulation that we identified as analogs of the target galaxy. We followed
their descendants and found 11 observed strong lensing galaxies that match in
stellar mass and size with the descendants at their redshifts. The observed and
simulated results are discussed, although no conclusive assessment is made
given the low statistical significance due to the small sample size.
Nevertheless, the test confirms that our proposed strategy is already feasible
with existing data and simulations. We expect it to play an even more important
role in studying galaxy evolution as more strong lens systems and larger
simulations become available with the advent of next-generation survey programs
and cosmological simulations.
