  Asteroids residing in the first-order mean motion resonances with Jupiter
hold important information about the processes that set the final architecture
of giant planets. Here we revise current populations of objects in the J2/1
(Hecuba-gap group), J3/2 (Hilda group) and J4/3 (Thule group) resonances. The
number of multi-opposition asteroids found is 274 for J2/1, 1197 for J3/2 and 3
for J4/3. Using both hierarchical clustering technique and colour
identification we characterise a collisionally-born asteroid family around the
object (1911) Schubart in the J3/2 resonance. There is also a looser cluster
around the largest asteroid (153) Hilda. Using N-body numerical simulations we
prove that the Yarkovsky effect (infrared thermal emission from the surface of
asteroids) causes a systematic drift in eccentricity for resonant asteroids,
while their semimajor axis is almost fixed due to the strong coupling with
Jupiter. This is a different mechanism from main belt families, where the
Yarkovsky drift affects basically the semimajor axis. We use the eccentricity
evolution to determine the following ages: (1.7+-0.7) Gyr for the Schubart
family and >~4 Gyr for the Hilda family. We also find that collisionally-born
clusters in the J2/1 resonance would efficiently dynamically disperse. The
steep size distribution of the stable population inside this resonance could
thus make sense if most of these bodies are fragments from an event older than
~1 Gyr. Finally, we test stability of resonant populations during Jupiter's and
Saturn's crossing of their mutual mean motion resonances. In particular we find
primordial objects in the J3/2 resonance were efficiently removed from their
orbits when Jupiter and Saturn crossed their 1:2 mean motion resonance.
