<p><a>Deserts,
such as the Namib, Sonoran, and Saharan, are regions that are unsuitable
habitats for many organisms. However, darkling beetles (Tenebrionidae),
specifically Pimeliinae, have appeared to flourish in otherwise inhospitable environments.
All organisms have heat shock proteins protecting cellular components from degradation
due to environmental stress such as desert heat. Modifications to heat shock
proteins may provide more efficient cellular protection allowing desert-dwelling
beetles to survive in regions where few other organisms are found. I performed
a study which analyzed heat shock protein 40 (Hsp40) homologs across Pimeliinae
by using targeted enrichment and high-throughput sequencing of seven genetic
loci from 142 taxa (25 tribes) to examine protein functionality and evolution.
I determined that the critical J domain of Hsp40 is conserved across pimeliine
taxa. Additionally, there were a variety of cysteine shifts within different
pimeliine tribes throughout six of the seven homologs, indicating possible
protein structure alterations. Maximum likelihood analyses of Hsp40 homologs
determined that despite the relationships between the tribes shuffling, taxa
remained within their respective tribes. In an effort to examine how Hsp40s may
have evolved alongside other behaviors and life histories, the tribe Adesmiini
(Tenebrionidae: Pimeliinae) was examined in detail. </a></p>
<p>Adesmiines
thrive in the arid regions of sub-Saharan Africa, northern Africa, and the
Palearctic. Despite having a few genera (i.e., <i>Onymacris</i>) which have
been the subject of extensive life history analyses, Adesmiini has undergone
few modern taxonomic studies. As a result, Adesmiini is a good candidate for
phylogenetic investigation. To investigate evolutionary relationships, 510
targeted loci across 47 specimens (41 species, 10 genera) were used to produce
a well-supported phylogeny. Current generic concepts were not in agreement with
the resulting topology. In addition to producing a molecular phylogeny, two
adesmiine traits of interest, activity time (diurnal/nocturnal) and substrate
usage (psammophily), were also examined. Since Adesmiini is a predominantly
diurnal tribe within a primarily nocturnal family, the activity time was mapped
to the topology. From this study’s tree, it was determined that there were at
least three shifts from diurnal to nocturnal throughout Adesmiini. Several
charismatic adesmiines occur on the dunes of southern Africa, so the shift to inhabiting
sand hills (psammophily) devoid of vegetation was also investigated.
Psammophily was determined to have arisen multiple times within Adesmiini, and
the topology revealed no clear indication to a single radiation of adesmiine
substrate usage. Finally, a study was performed on Adesmiini using the same
seven Hsp40 homologs as in the pimeliine functional genomics investigation. The
resulting phylogenies indicate a correlation between Hsp40 modification and
diurnal, psammophilous adesmiines. </p>