The environment plays a key role in the formation and evolution of galaxies. Clusters of galaxies are the most massive and virialized structures known in the Universe and therefore are the ideal laboratories for the study of environmental processes in galaxies. It is not an easy task to discern, between the properties of galaxies, which have been modulated by the environment or are products of internal processes of the same. This is due to the multi-component nature of clusters, which causes a large number of physical processes, with different temporal and spatial scales, to influence the evolution of the galaxies they host. For decades the properties of galaxies in clusters have been analyzed. However, even today there is a lack of knowledge about the properties of low-mass galaxies in different environments. This is due to the scarcity of spectroscopic data for these types of galaxies. This data gap will be alleviated by the new WEAVE wide-field spectrograph at the William Herschel Telescope (WHT). WEAVE has been developed by an international consortium in which Spain has played a key role in the design and construction phases of said spectrograph. Starting in mid-2021, the WEAVE spectrograph will run a series of maps that will answer key questions in modern astrophysics. One of these maps, related to the evolution of galaxies in clusters, is being led and designed by the IP and the work team of this project. Therefore, this project is presented with two main objectives:

1) scientific exploitation of the data from the mapping of galaxy clusters carried out by WEAVE.

2) obtain the necessary resources to continue developing the tasks assigned within the WEAVE consortium during the mapping stage.

This Project culminates a series of 2 previous projects that have been funded by this National Research Plan. In them, the necessary resources were obtained to carry out the tasks assigned to Spain within the WEAVE consortium during the design and manufacturing phases of the instrument. It is now when this 8-year work culminates and the stage of scientific exploitation of the data from this unique instrument begins, which will open a new era for the WHT telescope, which has played a key role in the takeoff of Spanish astronomy during the last three decades.