Abstract: The talk concerns several aspects of a class of stochastic coalescent processes. These coalescents arise as scaling limits in mathematical population genetics models. They are ``duals'' to measure-valued processes known as (generalized) Fleming-Viot processes. In special cases the correspondence between the genealogical process of a (super)diffusion and a coalescent process is well-known. The spatial (or structured) coalescents are particularly important in the study of asymptotic behavior of a class of interacting particle systems and the corresponding scaling limits.

I will attempt to describe most of the the above relations in the intuitive ``particle representation'' setting. Some interesting properties of (spatial) Lambda-coalescents will be discussed, as well as very interesting consequences for the asymptotics of the related interacting particle systems and their scaling limits.