The research team was founded by Juan Pedro M. Camacho (Ph. D. 1980, Universidad de Granada). His Ph.D. dissertation consisted of a general screening of chromosome number and meiotic behaviour of a high number of orthopteran species included in the major groups: Tettigonioidea, Pamphagoidea and Acridoidea. This work detected a lot of polymorphisms, including B chromosomes in the grasshopper Eyprepocnemis plorans, and opened the door to later studies specifically focused on cytotaxonomy, meiotic behaviour of chromosomal rearrangements, such as inversions and translocations, constitutive heterochromatin, nucleolus organiser regions (NORs) localization, and population cytogenetics of supernumerary heterochromatin such as B chromosomes and supernumerary chromosome segments.

    The second group member is Josefa (Pepi) Cabrero (Ph.D. 1985, Universidad de Granada). Her Ph.D. was focused on the analysis of a high number of species from the subfamily Gomphocerinae (Acrididae, Orthoptera) using two new techniques for the group: C-banding and silver impregnation. Both techniques permitted the detection of a huge number of interesting phenomena related to standard and supernumerary heterochromatin, chromosomal rearrangements and NOR location. We published about 20 papers with her findings. She also improved grasshopper breeding in our lab and developed the cytological analysis of grasshopper embryos and microfluorescence techniques for chromosome banding analysis.

    The joining of Mª Dolores (Lola) López-León (Ph.D. 1991, Universidad de Granada) to the group coincided with our interest on the transmission of some polymorphisms we had detected (i.e. the polysomy in Chorthippus binotatus, supernumerary chromosome segments in Chorthippus jacobsi and the B chromosomes in Eyprepocnemis plorans). She was still an undergraduate student when started to perform the necessary controlled crosses, and continued them during her graduation period. Her dissertation was exclusively devoted to the study of the biological meaning of the B chromosome system of the grasshopper E. plorans. Her experiments showed the existence of a strong last-male sperm precedence in this species, and that the three most widespread B chromosomes of this species lack drive and fitness effects. We named this new type of B chromosome as near-neutral B-chromosome. During her one year postdoc in Prof. Hewitt's lab (University of East Anglia, Norwich), she isolated a repetitive DNA that is present in both A and B chromosomes of E. plorans. She also learned fluorescent in situ hybridization (FISH) techniques in Prof. Heslop-Harrison's lab. Double FISH showed that E. plorans Bs are most likely derived from the X chromosome.

    The incorporation of Mohammed Bakkali to the research team has permitted us to analyse Moroccan populations of E. plorans. He is a graduate studying and his present work is focused on the study of the B chromosome polymorphism of E. plorans in Moroccan natural populations.

    Our last signing-up was Francisco (Paco) Perfectti (Ph.D.. 1995, Universidad de Granada). His Ph.D.. dissertation included the characterization of genetic variation in tree collections of cherimoya (Annona cherimola). His common interests with our group on several evolutionary biology topics, decided him to join us. Then, he stayed for more than one year in Prof. Jack Werren's lab (University of Rochester, NY), where he was working on very interesting projects related to the genetics of speciation. Now, he is beginning our molecular study of the B chromosomes of E. plorans.
 

    Thought this time, several other people have worked with us but, for diverse reasons, they are no longer with us. Anyway, their works are reflected in the group curricula and we like to remember them:

• Esther Viseras (Ph.D.. Universidad de Granada) mainly worked in the polysomy and iso-B chromosomes of Omocestus bolivari and the B chromosome system of the locust Locusta migratoria.
• Mª Cruz Pardo (Ph.D.. 1993, Universidad de Granada) performed a very tough  work on Locusta migratoria to analyse the mitotic instability of its B chromosomes, as well as their transmission. She was also able to do a stay of two months in Prof. Hewitt's lab (University of East Anglia, Norwich) to perform experiments that showed ejaculate nutrient transfer in E. plorans and L. migratoria. She was also involved in the study of the B chromosome system of E. plorans.
•  Jesús Navas-Castillo stayed a very brief but productive period, analysing diverse polymorphisms, mainly those for supernumerary chromosome segments.
• Jose Belda performed cytotaxonomical studies in the genus Chorthippus and a cytological analysis of spermatogenesis in Nezara viridula, a heteropteran with holocentric chromosomes, by means of C-banding and silver impregnation.
• Juan de Dios Alché worked in the B chromosome system of E. plorans, starting our analyses with the G-banding technique.
• Miguel Talavera collaborated in the transmission analysis of extra polysomic chromosomes in Chorthippus binotatus. He also analysed C-banding and NOR location in several species of Oedipodinae.
• Jose Herrera did the interpopulational controlled crosses that demonstrated the existence of genes in the A genome suppressing B drive in E. plorans.
• Michael Shaw performed the mathematical model and the computer program that was used by him and J.P.M. Camacho to make simulations that uncovered the biological meaning of what we called near-neutral B chromosomes.
• Angel Martín-Alganza analysed mating success in relation to B chromosomes, supernumerary chromosome segments, body size and condition, as well as other metric and meristic traits in E. plorans. He also analysed the prevalence of a mite genus Podapolipus in the natural population analysed.
• Antonio Jesús Castro López performed experiments in Locusta migratoria to analyse the effects of B chromosomes on several morphological traits, as well as the effect of multiple mating on female fitness.
• Sergio Zurita performed most experimental work leading to the demonstration of the substitution of a neutralized B by a new selfish B in the Torrox (Málaga, Spain) population.
• Estefanía (Fanny) Muñoz-Adelantado performed very interesting experiments in E. plorans demonstrating that both a genome parasite (B chromosome) and an ectoparasite (a mite genus Podapolipus) decrease egg fertility when there is mating scarcity.

As deduced from our history, in the beginning we were cytogeneticists, but our scope has now been broaden to show interest on evolutionary biology, in a wide sense, with special emphasis on host-parasite coevolution, evolution of mating systems and sexual selection, and the genetics of speciation. Our immediate research activity is focused on the molecular analysis of B chromosomes in E. plorans, in collaboration with Tim Sharbel who has microdissected two B variants.