In the city, frogs do not feel as comfortable as in the wild nature because of dirty water, a lack of food, and dangers at every turn. That is why the life of frogs in urban areas is shorter. However, they do not leave these habitats, but adapt to them. Apparently, there are two ways to adapt: either become more tolerant or increase the number of progeny.
Every spring from 1998 to 2001, Elena A. Severtseva and her colleagues from the Biological Faculty of the Moscow State University studied the spawn of two frog species (Rana temporaria and Rana arvalis) most common in Moscow parks and ponds. The scientists counted the number of layings and the quantity of eggs in each laying and measured the diameter of eggs and their yolks using a microscope.
In average, Moscow frogs have smaller eggs than their sisters in the countryside, but each urban frog lays several hundred eggs more than the rural one. The egg diameter is about one millimetre, and the difference between egg sizes in the city and suburbs constitutes several decimal fractions of millimetre, but that is sufficient to gain in quantity. At the same time, urban conditions do not change the yolk size in relation to that of the whole egg; sometimes yolks of Moscow frogs are even larger. Therefore, the embryo has a sufficient food supply to grow into the tadpole, though tadpoles from small eggs need a longer time for development.
Alexander Barne | alphagalileo
Single mutation dramatically changes structure and function of bacteria's transporter proteins
23.10.2019 | New York University
Bacterial lifestyle alters the evolution of antibiotic resistance
23.10.2019 | University of Pittsburgh
After first reporting the existence of quantum knots, Aalto University & Amherst College researchers now report how the knots behave
A quantum gas can be tied into knots using magnetic fields. Our researchers were the first to produce these knots as part of a collaboration between Aalto...
Researchers have succeeded in creating an efficient quantum-mechanical light-matter interface using a microscopic cavity. Within this cavity, a single photon is emitted and absorbed up to 10 times by an artificial atom. This opens up new prospects for quantum technology, report physicists at the University of Basel and Ruhr-University Bochum in the journal Nature.
Quantum physics describes photons as light particles. Achieving an interaction between a single photon and a single atom is a huge challenge due to the tiny...
A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)
It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...
Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.
Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...
02.10.2019 | Event News
02.10.2019 | Event News
19.09.2019 | Event News
23.10.2019 | Materials Sciences
23.10.2019 | Physics and Astronomy
23.10.2019 | Medical Engineering