Roy H. J. Erkens

Roy H. J. Erkens
Maastricht University | UM · Faculty of Science and Engineering, Maastricht Science Programme

PhD

About

189
Publications
29,127
Reads
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2,453
Citations
Additional affiliations
April 2012 - present
Maastricht University
Position
  • Lecturer Evolutionary biology and Botany
January 2007 - March 2012
Utrecht University
Position
  • Professor (Assistant)
December 2000 - December 2006
Utrecht University
Position
  • PhD Student

Publications

Publications (189)
Article
Full-text available
The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiver-sity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxo-nomic impediment to biodiversity research and conservation planning. The taxonomic impedi...
Article
Background Standing desks have been brought into the education environment to reduce sedentary behavior among students. The current study explored the effects of standing in tutorial group meetings on learning among undergraduate students. Methods Ninety-six participants were randomly allocated to a Sit or Stand group, with 2-hour tutorial group m...
Book
Full-text available
The urge to organise the world around us is an essential part of human nature. Naming and categorising enable us to store and access information ef ciently. The need to name and categorise extends to the natural world and, in particular, to living organisms. The science underpinning this area of knowledge is called Taxonomy, and is as old as humani...
Article
Full-text available
The flowering plant family Annonaceae includes important commercially grown tropical crops, but development of promising species is hindered by a lack of genomic resources to build breeding programs. Annonaceae are part of the magnoliids, an ancient lineage of angiosperms for which evolutionary relationships with other major clades remain unclear....
Article
Full-text available
This study explored the effects of using standing desks in tutorial meetings on the physical activity behavior (PAB) of undergraduate students. Standing desks have been introduced to minimize the detrimental health effects of prolonged sedentary behavior (SB). The effectiveness of using standing desks has not been explored among undergraduate stude...
Article
Full-text available
As a result of concerted efforts of the community of Annonaceae taxonomists, increasingly detailed knowledge of the diversity of the Neotropical genera has been documented. With the exception of just two large genera, Annona and Xylopia, all Neotropical Annonaceae have been revised within the last 25 years. Subsequent to these publications, many ne...
Preprint
Full-text available
Deep relationships and the sequence of divergence among major lineages of angiosperms (magnoliids, monocots and eudicots) remain ambiguous and differ depending on analytical approaches and datasets used. Complete genomes potentially provide opportunities to resolve these uncertainties, but two recently published magnoliid genomes instead deliver fu...
Article
Full-text available
Targeted enrichment and sequencing of hundreds of nuclear loci for phylogenetic reconstruction is becoming an important tool for plant systematics and evolution. Annonaceae is a major pantropical plant family with 110 genera and ca. 2,450 species, occurring across all major and minor tropical forests of the world. Baits were designed by sequencing...
Article
Standing classrooms could potentially counteract excessive sedentary behavior. This paper describes the protocol for an exploratory longitudinal randomized controlled trial aimed at studying the effects of standing during tutorials on learning in undergraduate students. Learning is operationally defined as the use of interactions that are conducive...
Article
Full-text available
The Global Strategy for Plant Conservation (GSPC) was established by the Conference of Parties in 2002 to decrease the loss of plant diversity, reduce poverty and contribute to sustainable development. To achieve this overarching goal, the GSPC has established a series of targets, one of which is to ensure that plant diversity is well understood, s...
Preprint
Full-text available
Targeted enrichment and sequencing of hundreds of nuclear loci for phylogenetic reconstruction is becoming an important tool for plant systematics and evolution. Annonaceae is a major pantropical plant family with 109 genera and ca. 2450 species, occurring across all major and minor tropical forests of the world. Baits were designed by sequencing t...
Article
Full-text available
Nitraria is a halophytic taxon (i.e., adapted to saline environments) that belongs to the plant family Nitrariaceae and is distributed from the Mediterranean, across Asia into the south-eastern tip of Australia. This taxon is thought to have originated in Asia during the Paleogene (66–23 Ma), alongside the proto-Paratethys epicontinental sea. The e...
Data
Botanical materials. Here we list all the materials that were given on loan from different herbaria to carry out this study
Data
Measurements of morphological characteristics and FTIR chemical spectra of extant Nitraria and Peganum pollen (all morphological measurements in µm)
Data
Phylogenetic tree file of Nitrariaceae obtained from Zhang et al. (2015) and used to create the phylomorphospace and phylochemospace
Data
Coordinates of the plotted specimens in Fig. 1, obtained from GBIF, Tropicos or own material described in Appendix S2
Data
Summary table of the 24 morphological characters used to describe the Nitraria and Peganum pollen in this study
Data
Boxplots comparing the 18 numerical morphological characters used for pollen morphological analysis between the eight studied species
Article
Full-text available
We present revisions of the Neotropical genera Ruizodendron and Pseudephedranthus (Annonaceae). Ruizodendron includes a single species R. ovale. Pseudephedranthus now comprises two species, with the description of the new species P. enigmaticus sp. nov. extending the range of the genus beyond the Upper Rio Negro region of Brazil (Amazonas) and adja...
Article
The molecular clock hypothesis is an important concept in biology. Deviations from a constant rate of nucleotide substitution have been found widely among lineages, genomes, genes and individual sites. Phylogenetic research can accommodate for these differences in applying specific models of evolution. Lineage-specific rate heterogeneity however ca...
Article
Full-text available
http://advances.sciencemag.org/content/2/8/e1600883/tab-e-letters
Article
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Dispersal and colonisation are key processes determining species survival, and their importance is increasing as a consequence of ongoing habitat fragmentation, land-use change and climate change. Identification of long-distance dispersal events, including upstream dispersal, and of the dispersal mechanisms and resulting spatial dispersal patterns...
Article
Full-text available
Only few biogeographic scenarios capture the imagination as much as the closure of the Isthmus of Panama. The establishment of this connection ended the “splendid isolation” of the South American continent (Simpson 1980), a continent that had been unconnected to any other land mass for over 50 million years. When the Isthmus rose out of the water s...
Article
A taxonomic revision of the genus Guatteria, including the former genera Guatteriella, Guatteriopsis and Heteropetalum is given. Within the genus Guatteria 177 species are recognized, 25 of which are new. Included are chapters on the history of the taxonomy of the genus, morphology, wood anatomy, karyology, palynology, chemistry, flower biology and...
Article
Full-text available
The molecular phylogenetic placement of Diclinanona (Annonaceae) has been debated in the literature for a decade. On the basis of morphological studies the genus was thought to be related to genera now all placed in subfam. Annonoideae. This early hypothesis was supported by the first phylogenetic analyses of Annonaceae. However, more recently a pl...
Article
Guatteria Ruiz & Pavón (1794: 85) is the largest genus of Annonaceae with about 210 recognized species (Chatrou et al . 2012, Maas et al. 2011). It comprises small- to medium- sized trees, rarely canopy trees or shrubs, and only two species are lianas, Guatteria scandens Ducke (1925:10) and G. fractiflexa Maas & Westra (2008: 491; Erkens et al . 20...
Article
Full-text available
Unlocking the vast genomic diversity stored in natural history collections would create unprecedented opportunities for genome-scale evolutionary, phylogenetic, domestication and population genomic studies. Many researchers have been discouraged from using historical specimens in molecular studies because of both generally limited success of DNA ex...
Data
Percentage, mean and maximum read coverage over all nucleotide positions for chromosomes, scaffolds or linkage groups (LG). (DOCX)
Data
Average nucleotide mis-incorporation rates (substitutions per base) observed in fresh and collection DNA. (DOCX)
Data
Integrity of herbarium DNA. Top, DNA extracts from L. anagyroides fresh (A) and herbarium (B), A. thaliana herbarium (C) and fresh (D), L. tulipifera herbarium (E) and fresh (F), and 1 kb Plus DNA Ladder (Invitrogen), after electrophoresis on 0.8% agarose gels. Bottom, herbarium DNA extracts of A. bisporus (G), P. ostreatus (H) and L. bicolor (I),...
Data
ANOVA on nucleotide mis-incorporation rates for each of the six nucleotide substitution types. (DOCX)
Data
Best BLASTx hits of CDS regions with high number of SNPs or indels. (DOCX)
Data
Genotyping and total number of SNPs and indels in coding sequences (CDS). (DOCX)
Article
Full-text available
Despite ever-growing popularity of species distribution models (SDM), their performance under conditions of spatially biased data has rarely been studied in detail. Here we explore the effect of a known spatial bias on the predictive ability of Maxent models, using five species of the genus Asplenium with variable reproductive modes. The models wer...
Article
Full-text available
The pantropical flowering plant family Annonaceae is the most species-rich family of Magnoliales. Despite long-standing interest in the systematics of Annonaceae, no authoritative classification has yet been published in the light of recent molecular phylogenetic analyses. Here, using the largest, most representative, molecular dataset compiled on...
Article
Full-text available
Biologists are fascinated by species-rich groups and have attempted to discover the causes for their abundant diversification. Comprehension of the causes and mechanisms underpinning radiations and detection of their frequency will contribute greatly to the understanding of the evolutionary origin of biodiversity and its ecological structure. A dat...
Article
The pantropical flowering plant family Annonaceae is the most species-rich family of Magnoliales. Despite long-standing interest in the systematics of Annonaceae, no authoritative classification has yet been published in the light of recent molecular phylogenetic analyses. Here, using the largest, most representative, molecular dataset compiled on...
Article
It is important that taxonomic knowledge is disseminated by those who possess it. This can be carried out via online databases, printed publications or training in taxonomic practice. For Annonaceae, the online database AnnonBase includes all published names of Annonaceae at any rank worldwide. Recently, an updated index to genera, species and infr...
Article
Full-text available
Populations established by long-distance colonization are expected to show low levels of genetic variation per population, but strong genetic differentiation among populations. Whether isolated populations indeed show this genetic signature of isolation depends on the amount and diversity of diaspores arriving by long-distance dispersal, and time s...
Data
Full-text available
Genotypes of parent sporophytes used to obtain spores for the experiment. Genotypes (rows) are based on four polymorphic microsatellite loci per species (columns), and differ between all used plants. Different alleles are designated by different letters. Certain heterozygotes (diploids with two alleles or tetraploids with three or four alleles) are...
Data
Genotypes of parent sporophytes used to obtain spores for the experiment. Genotypes (rows) are based on four polymorphic microsatellite loci per species (columns), and differ between all used plants. Different alleles are designated by different letters. Certain heterozygotes (diploids with two alleles or tetraploids with three or four alleles) are...
Article
Full-text available
Previous studies on the reproductive biology of ferns showed that mating strategies vary among species, and that polyploid species often show higher capacity for self-fertilization than diploid species. However, the amount of intraspecific variation in mating strategy and selfing capacity has only been assessed for a few species. Yet, such variatio...
Article
Full-text available
Premise of the study: Studies on the biogeography and population genetics of the widespread European rock ferns Asplenium scolopendrium, A. trichomanessubsp. quadrivalens, Polystichum setiferum, and P. aculeatumwould potentially yield interesting new insights into the colonization capacities of ferns. Markers with sufficient resolution for detaile...
Article
Annonaceae form the most diverse family within the Magnoliales. In 1990 an Index to generic names of Annonaceae was published and in 1994 an Index to Neotropical species of Annonaceae was compiled. Especially the latter proved an immensely useful tool for Neotropical botanists. Here, we present an updated Index of all valid names in Neotropical Ann...
Article
Aim Rain forest-restricted plant families show disjunct distributions between the three major tropical regions: South America, Africa and Asia. Explaining these disjunctions has become an important challenge in biogeography. The pantropical plant family Annonaceae is used to test hypotheses that might explain diversification and distribution patter...
Data
Maximal intraspecific genetic distances, minimal genetic distances towards the nearest neighbour and their ratio. Data are presented for all taxa with multiple individuals in the dataset. Ratios are calculated as maximal interspec. distance/minimal intraspec. distance. All distances are uncorrected P-distances based on the combined rbcL and trnL-F...
Data
rbcL and trnL-F sequence information. Sequence origin (O = sequenced by authors in previous study, G = downloaded from Genbank, N = sequenced for this study), voucher information (herbarium, collection number. EB = Ecology & Biodiversity Group, Utrecht University voucher collection), collector, publication information and Genbank accession numbers...
Data
Used species complexes. Overview of species merged into a single complex because of identical chloroplast genomes. All sequences were named after the diploid cpDNA donor, unless this donor could not be included (Dryopteris “semicristata”, see text). (DOC)
Article
Full-text available
Although consensus has now been reached on a general two-locus DNA barcode for land plants, the selected combination of markers (rbcL + matK) is not applicable for ferns at the moment. Yet especially for ferns, DNA barcoding is potentially of great value since fern gametophytes--while playing an essential role in fern colonization and reproduction-...