Student projects ("stages")
Research projects for students (‘stage-onderwerpen voor studenten’) supervised by Menno Schilthuizen, NCB Naturalis
PLEASE NOTE: I will be writing a book between April 2012 and April 2013. For that reason I will only be taking new students from May 2013 onwards. Please check the homepages of my PhD student Liew Thor-Seng and my postdocs Heike Kappes and Masaki Hoso for alternative options. (See also at the bottom of this page.)
(menno.schilthuizen@ncbnaturalis.nl; tel. 071-5687769
Below follow brief descriptions of possible research projects (“stages”) for Master of Science, Bachelor of Science, or HBO students. Preference is given to the projects below, which fall within the two research programmes (“left-right asymmetry” and “human-induced evolution”) that currently are given priority in NCB Naturalis.
BSc- or MSc-project:
[currently not available] Molecular phylogenetics and evolution of genital morphology in small carrion beetles (Coleoptera: Cholevidae)
Synopsis: The reproductive system of polyandrous and/or polygynous animals is known to evolve rapidly due to what has been termed the “three-way tug of war” of sexual selection. This has led to species radiations in which most of the morphological differentiation is in primary and secondary sexual traits. Many groups of insects show this phenomenon. Cholevidae, for example, are small, carrion-inhabiting beetles that show a strong evolutionary radiation in the Holarctic region and potential for the application in forensic entomology. Externally, the species are very similar. The genitalia, however, show great diversification. In this project, the aim is to reconstruct a molecular phylogeny of a selection of species, and to map the evolution of genital character traits on the tree.
Methods: Field sampling of cholevids throughout Europe; preparing genital mounts; scanning electron microscopy; identification; DNA-extraction; PCR; DNA-sequencing; molecular phylogenetics.
BSc- or MSc-project:
Mirror-image genitalia in Dutch deathwatch-beetles
Synopsis: Ernobius mollis, a common Dutch species of the beetle family Anobiidae (deathwatch beetles or wood worms) has males with asymmetric (chiral) genitalia. This species has the rare phenomenon that within the species males occur with either dextral and sinistral mirror-image forms. This is called “antisymmetry”; much more normal is “directional asymmetry”, in which within one species only one of the two mirror-image forms exist. The student will study collection material and field-collected specimens of Ernobius to answer the following questions: (1) is antisymmetry also found in other Ernobius species? (2) what are the frequencies of dextral and sinistral present throughout The Netherlands? (3) is genital chirality correlated with visceral chirality (the orientiation of the other internal organs)? (4) what is the relevance of mirror image reversal for mate choice?
Methods: genital preparation from preserved and fresh-collected material; field work; anatomy; mating trials; statistics
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(HBO or University) BSc-project:
DNA-barcoding of caterpillars from native and exotic Prunus
Synopsis: Contrary to expectation, we have recently discovered that the exotic American birdcherry (Prunus serotina) harbours a great diversity of native herbivorous Lepidoptera, almost as diverse and abundant as its closest relative, Prunus padus. We have preserved caterpillars on pure ethanol from 90 trees of each host tree, and identified many of them morphologically. However, identifications are often doubtful, and in some cases (Geometridae) impossible. In this project, these samples will be identified independently based on DNA-barcoding.
Methods: DNA-extraction, PCR, DNA-sequencing, barcode identification.
MSc-project:
Adaptive host-shift of fruit flies (Diptera: Tephritidae) and leaf beetles (Coleoptera: Chrysomelidae) on exotic plants
Synopsis: More and more exotic plant species are entering indigenous ecosystems in the Netherlands. In many cases, the plants (often "escaped" via gardens or bird seed) do not bring any specialised herbivores with them and are available for native herbivorous insects to colonise them. In principle, such host-shift might involve rapid evolutionary adaptation in the herbivore, eventually possibly even leading to sympatric speciation. In a programme run in collaboration with the University of Groningen, we aim to do a broad inventory of native specialist herbivorous insects on exotic, invasive plant species, and do a pilot investigation of genetic differentiation in a selected few of the insect species. Two systems that offer potential in this respect are the species of Tephritidae and Chrysomelidae. Several genera of these herbivorous insects are monophagous, adapting rapidly to novel host plants. Field studies in 2008-2010 have shown that exotic tree species that grow in the wild in the Netherlands, e.g., Lonicera tatarica, Prunus serotina and Rosa rugosa have been colonized by native fruit fly and leaf beetle species. The aim of this project is to do genetic analysis (SNP-genotyping) on samples (both existing and newly-collected) of one or more species to investigate whether differentiation is detectable between populations on the native and on the exotic host plants.
Methods: Field work (in spring or early summer) in Meijendel, National Park Zuid-Kennemerland, and/or Drenthe; DNA-extraction; PCR; population genetic analysis.
MSc-project:
Evolutionary changes in colour morphs in Cepaea nemoralis snails in "heat islands" in urban areas
Synopsis: The shell colour and banding pattern in the common garden snail Cepaea nemoralis are highly variable. The genetics of the colour variation is known, as well as the natural selection pressures on them. One important selection pressure is thermal adaptation: light-coloured shells protect the snail from overheating on hot summer days. In a study in Groningen, we have shown that due to climate change, the light morphs have increased in frequency over the past 43 years. In this project, the aim is to detect the signature of adaptation to so-called “heat islands” in urban areas. In 2011, heat islands were mapped in the city of Rotterdam, showing that in summer, some parts of the city were up to 7 degrees C hotter than other parts. We expect that in these areas, in similar habitats, the snails will be lighter-coloured. The student will test this by sampling a large number of Cepaea populations throughout the city of Rotterdam, scoring morph frequencies, measuring reflectance and correlating these with small-scale temperature records.
Methods: Field work in Rotterdam (late april to mid-September), scoring shell colour polymorphisms; spectrometry; statistical analysis
MSc- or BSc-projects supervised by PhD student Liew Thor-Seng (see linked pdf):
Cost of adaptive evolution in shell ornamentations (Gastropoda: Diplommatinidae: Opisthostoma)
..and by postdoc Heike Kappes:
Heat islands and snails in big cities
Sunday, February 26, 2012