Speciation is a rare phenomenon. Yet in Mayotte scientists (among them Jean David, IGGIPOP) described a population of D. yacuba drosophila feeding on the fruit of the Morinda tree which is toxic to flies on the african continent. This could provides the geographic isolation and the ecological specialization that are necessary to speciation.
The black bee, a species well adapted to our climate, is in great danger.
Already weakened by different stresses such as parasites or pesticides, the black bees tend to be replaced by imported bees, which are less well adapted and depend on humans to survive.
The Pollinis association filmed a press conference given with FEDCAN (which President is Lionel Garnery (EVOLBEE)) to alert the audience of the dangers facing the black bees. To see the video.
The school field « Diversity and humans » has been held for the second time in Oku (Cameroon). It was the opportunity for students and teachers from France and Cameroon to gather for a few days in an enchanting site to share a training both theoretical and practical. It was organized by Philippe Le Gall (DEEIT) and collegues. Nicolas Pollet (Polygnome) participated in this.
Most often the repartition between the sexual chromosomes, X and Y, is even in the spermatozoides. However, in some drosophila populations there is a strong bias for X.
The team of Catherine Montchamp-Moreau (IGGIPOP) at EGCE in collaboration with collegues of the Laboratoire de Biométrie et Biologie Evolutive in Lyon and of the Institut de Biologie du Développement in Marseille looked further. A key gene involved in the transmission of chromosome Y in the male gamets was identified on chromosome X. This work was published in PNAS:
« Rapid evolution of a Y-chromosome heterochromatin protein underlies sex chromosome meiotic drive« , par par Quentin Helleu, Pierre R. Gérard, Raphaëlle Dubruille, David Ogereau, Benjamin Prud’homme, Benjamin Loppin et Catherine Montchamp-Moreau publié dans PNAS le 15 mars 2016. DOI:10.1073/pnas.1519332113.
A brief communication was posted on the web site of l’INEE.
The work of Paul André Calatayud and its team in Kenya has been published in the journal Agriculture, Ecosystems & Environment: P.-A. Calatayud, E. Njuguna, S. Mwalusepo, M. Gathara, G. Okuku, A. Kibe, B. Musyoka, D. Williamson, G. Ong’amo, G. Juma, T. Johansson, S. Subramanian, E. Gatebe, B. Le Ru. Can climate-driven change influence silicon assimilation by cereals and hence the distribution of lepidopteran stem borers in East Africa? Agriculture, Ecosystems & Environment, 2016, Vol 224, p. 95–103. doi:10.1016/j.agee.2016.03.040.
Scientists showed that two species of corn insect pests in Kenya, Busseola fusca and Chilo partellus, display different food behavior depending on the concentration of silicon in the plant’s leaves. Silicon concentration varies with temperature and then with altitude. The hypothesis is then that climate change could modify the repartition of the two insects species.
This work is the subject of a news in IRD: Actualité scientifique n°496