– Afrothismia saingei, a new species of Burmanniaceae (tribe Thismieae) from Mt. Kupein South-West Cameroon is described and illustrated. It differs from the other species of the genusAfrothismia by the size of its flower, the long, distinctly heteromorphic tepals with fringed basalextensions, the dorsal invagination of the perianth tube and the unique shape of the internal flange.

The brain cell karyotypes of six New World sand flies are described and compared. Lutzomyia trapidoi has three pairs of chromosomes, 2N = 6. The other species, L. gomezi, L. erwindonaldoi, L. carmelinoi, L. walkeri and L. columbiana, have four pairs of chromosomes, 2N = 8. No heteromorphic chromosomes were observed. Cytogenetic similarities among sand fly species are discussed.

The evolution of a pair of chromosomes that differ in appearance between males and females (heteromorphic sex chromosomes) has occurred repeatedly across plants and animals. Recent work has shown that the male heterogametic (XY) and female heterogametic (ZW) sex chromosomes evolved independently from different pairs of homomorphic autosomes in the common ancestor of birds and mammals but also t...

Taxometric method, invented by Paul Meehl (1965) and developed by him and a number of colleagues, is a family of procedure for subjecting parts of a certain class of theories to risky tests. The theories in question postulate the existence of a latent category, the taxon, and its complement class. A taxon is negatively defined as a " non-arbitrary latent category. " It does not appear to be pos...

In a recent study, Steel and Sanderson defined and characterized phylogenetically decisive sets of taxon sets. A set is called phylogenetically decisive if regardless of the trees chosen for each of its taxon sets, as long as these trees are compatible with one another, their supertree is always unique. This implies that the sampled taxon sets always lead to a unique supertree, regardless what ...

Fluorescence in situ hybridization of Anopheles darlingi and A. nuneztovari demonstrated nucleolar organizer region activity at the end of the fourth larval instar, when the nucleolar organizer regions underwent gradual condensation. The heteromorphic sex chromosomes showed intraindividual size variation in the rDNA blocks located in the pericentromeric region and this coincided with the locati...

In Drosophila species of the obscura group, males exhibit sperm-heteromorphism, simultaneously producing both long sperm, capable of fertilization, and short sperm that are not. The production of multiple sperm types calls into question whether mating system correlates, such as sperm length and number trade-offs and female remating behavior, are the same as previously described in sperm-monomor...