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In the struggle for existence and the inheritance of one’s own alleles, it is strategy to focus on fertilisation. During sexual selection, a form of natural selection, the competition aims at gamete fertilisation, often resulting in extreme phenomena, suboptimal for survival of the individuals. Textbook examples for such cases, are the ornaments of the peacock, the deer antlers, and the jumping spiders I study: males often have a chelicerae that is exceeding their full body size. Sexual selection can also cause sexual dimorphism as one sex (usually the females) chooses, and the opposite sex (usually males) competes.

My research focuses on the jumping spider genus Bathippus of New Guinea, which have extreme sexual chelicerae dimorphism (ESCD). In most species, males have enormous chelicerae, twice-thrice the length of the prosoma, used to compete with rivals to secure females. Originally, I intended to investigate the cost-benefit differences in different high altitude. To carry out such research, I had to compare the chelicerae of conspecific males living at different altitudes. However, when sorting specimens into morpho-species, I faced a problem and without properly addressing it, it is impossible to answer the question. One of the selection criteria is diversity (because the success of different versions must be different), but in the shape of the chelicerae, the number and shape of the extra teeth on it, there was much more diversity than in the characters traditionally used in taxonomy (male pedipalps). To solve the problem, I named the teeth and mapped them into already existing combined (morphological and molecular-based) phylogenetic trees. Since sexual selection is one of the driving forces of speciation, reproductive isolation is an important and fundamental requirement. Whether males with different chelicerae but similar palps are able to mate with the same female still requires further investigation. Many of the examined specimens are more than 60 years old, so DNA extraction is not possible, and obtaining new specimens is quite difficult.

During the investigations, I not only found the species described so far (but only known based on the original Latin species descriptions) and illustrated them with modern multifocal micrography, but also found new species for science as well.