This has been shown by an international research team directed by Anna Qvarnström at Uppsala University in today’s Net edition of Science. They demonstrate that the gene for this sexual preference is found on the sex chromosome that is inherited from the father and that only females have a copy of. The discovery sheds new light on how new species are formed.
The formation of new species takes millions of years. It often happens when a population (group of individuals) is divided and separated geographically and then adapts to disparate environments over thousands of generations. For instance, the earth’s ice ages have led to many such population splits. But divided populations often come into contact with each other before they have had time to become entirely sexually isolated from each other. When individuals mate with each other from such split populations that have not quite become separate species, their offspring (so-called hybrids) often have limited viability.
Anna Qvarnström’s research team from Uppsala University in Sweden, working with scientists from Norway, the Czech Republic, the US, and Holland, have studied natural hybridization between two closely related bird species, the collared flycatcher and the pied flycatcher. The two flycatcher species (or “quasi species”) have come into contact with each other after having been separated during the last ice age. The question they addressed was whether the flycatchers will conclude the species formation that is under way and become entirely sexually isolated from each other or, instead, if they will meld into the same species again.
“We found that females in the hybrid zone develop a sexual preference for males belonging to their own species and that this preference is determined by genes located on the sex chromosome,” says Anna Qvarnström.
In birds, in contrast with most other animals, it is the females that are the so-called heterogametic sex. Their sex chromosomes are called ZW and correspond to XY in humans. In birds, it is the female that is ZW and the male ZZ, but in humans men are XY and women XX. The results show that the preference for their own species is sited on the sex chromosome that the females inherit from their father. The same chromosome also houses the genes that govern the development of the species-specific plumage.
“When genes regulate species-specific features and the preference for these are located close to each other in the DNA, in this case on the same chromosome, species formation is favored. Therefore, the probability of these two flycatcher species merging into the same species again is small,” says Anna Qvarnström.
It is possible that this will prove to be a general pattern that can explain how new species can continue to exist even if they occasionally hybridize with each other.
Protein interaction helps Yersinia cause disease
21.08.2018 | Schwedischer Forschungsrat - The Swedish Research Council
Nanobot pumps destroy nerve agents
21.08.2018 | American Chemical Society
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
21.08.2018 | Power and Electrical Engineering
21.08.2018 | Life Sciences
21.08.2018 | Medical Engineering