Giribet was born in Burgos and grew up in Vilanova i la Geltrú, Catalonia to a legal administrator and an engineer who worked in nuclear power plants. As a boy, he enjoyed windsurfing, beachcombing, and collecting sea shells. He attended, and then graduated from, the University of Barcelona in 1993, with bachelor's degrees in zoology and fundamental biology. He completed his doctorate in animal biology in 1997.[4] He then moved to the American Museum of Natural History for postdoctoral research with Ward Wheeler, and from there moved to Harvard University in 2000, where he went through the ranks until becoming full professor in 2007, Alexander Agassiz Professor of Zoology in 2013, and Harvard College Professor in 2017.[5]
In 2001, with his colleagues from Australian Museum studied the systematics of some Arthropoda species.[9]
In 2002, he and Ward Wheeler suggested that the molluscan bivalve group Anomalodesmata should be classless, and that the orders Myoida and Veneroida are not monophyletic.[10]
The same year, he, Gregory Edgecombe, and their colleagues studied the phylogenetics of harvestmen, Opiliones, using data from 18s and 28s rRNA genes and morphology. Based on these analyses, they proposed that Dyspnoi and Laniatores formed the clade Dyspnolaniatores, which should be used as new classification for Opiliones.[11] His later studies corroborated instead the traditional clade Palpatores, formed by Eupnoi and Dyspnoi.[12]
In 2007, he traveled to New Zealand for intensive sampling of daddy longlegs and other invertebrates.[4] In August 2007, he traveled to Florida, where he demonstrated that mite harvestmen found there are relatives of West African species, because when the supercontinent Pangea broke up the North American part took some of those species with it.[15]
In 2009, he discovered the origin and evolution of animal organ systems by studying such bilaterian groups as Acoela and Nemertodermatida, which also showed that Acoelomorpha is not a sister group to them. During the same study he also suggested that the genus Xenoturbella is not a part of Deuterostoma super phylum, and that the genus Symbion and the Deuterostoma actually belong to the Bryzoa and Entoprocta subphyla.[16]
In 2022, a research group led by him and Prashant P. Sharma, his former Ph.D. student, showed that Arachnida is not monophyletic, using a dataset of over 500 genome libraries and morphology.[18] In that study, horseshoe crabs were placed inside the arachnids, which suggests a complex history of terrestrialization in Chelicerata and challenges the century-old dogma of a single colonization of land in arachnids.
In 2023, his laboratory produced the first complete genome sequence of Onychophora, commonly known as the velvet worms.[19]
Rob DeSalle; Gonzalo Giribet (2002). Techniques in Molecular Systematics and Evolution (1st ed.). Birkhäuser. ISBN978-3764362577.
Rob DeSalle; Gonzalo Giribet (2002). Ward Wheeler (ed.). Molecular Systematics and Evolution: Theory and Practice (1st ed.). Birkhäuser. ISBN978-3034894425.
^Jon Mallatt; Gonzalo Giribet (2006). "Further use of nearly complete 28S and 18S rRNA genes to classify Ecdysozoa: 37 more arthropods and a kinorhynch". Molecular Phylogenetics and Evolution. 40 (1): 772–794. doi:10.1016/j.ympev.2006.04.021. PMID16781168.