Evolutionary theory predicts that species can diverge if different females choose different characteristics in males. Yet females often pay attention to traits that reveal something about the quality of a male. As a result, females are likely to share the same preferences. In Lake Victoria cichlid fish, Martine Maan found a solution for this paradox: in different species, different traits reveal male quality.
She examined two closely related species, one with blue males and the other with red males. Females prefer males of the right colour, blue or red, and within those categories they choose the most brightly coloured males. They do so for good reasons: brightly coloured males from both species carry fewer parasites and are thus in better condition. Moreover, both species are adapted to different infection risks, which are associated with a difference in water depth and food choice. It is therefore in the females’ interest to mate with their own males.
Red and blue light
Yet how did these differences evolve? The red species occurs in deeper water than the blue species and therefore experiences different light conditions. Behavioural experiments showed that both species have adapted to this: the red species is more sensitive to red light and the blue species is more sensitive to blue light. For females of the red species, red males are therefore more conspicuous than blue ones, and vice versa. Males of other colours are inconspicuous and unattractive, and therefore produce few offspring. Eventually only the bright red and bright blue fish remain, and two separate species can arise.
Due to the introduction of the Nile perch, deforestation and population growth, water transparency in Lake Victoria is declining. In turbid water, cichlid females are less choosy and males are less brightly coloured. This research therefore underlines the importance of measures to counteract the ongoing eutrophication of the lake.
Martine Maan | alfa
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy