The animals and plants of our planet are becoming extinct under the pressure of civilization. The scientists have counted that one species vanishes from Earth every hour. The mammoth, passenger pigeon, gare-fowl, Steller`s sea cow - these are the most well-known of extinct species, but hundreds of species are next in turn. Can the scientists forecast what species is the first in this succession and what species is not under the threat of complete extinction? If the answer is known, the effort and funds intended for the preservation of natural resources could be distributed correctly. Leonard Polishchuk, Ph. D. (Biology), research assistant of the Chair of General Ecology, Faculty of Biology, Lomonosov Moscow State University, has found a mathematical index of animal vulnerability.
It is common knowledge that the species of large animals that propagate themselves slowly and produce scarce posterity extinct earlier than others. Therefore, Leonard Polishchuk was looking for the characteristic of extinction risk among common demographic and ecological parameters. The researcher analyzed several parameters for 90 species mammal inhabiting the territory of the former USSR: life interval, quantity of litter, body weight of a sexually mature female, annual prolificacy and the number of posterity that each specific animal species produces within the entire lifetime. Applying the logistic regression method, he compared the above parameters to the probability of these species` registration in the Red Book. The most appropriate characteristic has appeared to be natural annual prolificacy, i.e. the number of daughters born by a female within a year.
The leaders of this index have turned out to be the rodents: common shrew (11.4), rabbit (10.5), Pallas` pika and steppe mouse-hare (8.8 è 7.9), field mouse (7.7), Alpine hare and European hare (5.0 è 4.4) - these species are well-known for their vitality.
About one third of all investigated species is characterized by the index exceeding 2.9. Almost all the species registered in the Red Book are grouped closer to the end of the list - their production/mortality ratio is lower than the above value. The list is ended by the walrus (0.17), bison (0.20), and the sea-otter (0.25), which were on the verge of extinction in the 19th century.
Elena Krasnova | Informnauka
The hidden structure of the periodic system
17.06.2019 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)
Tiny probe that senses deep in the lung set to shed light on disease
17.06.2019 | University of Edinburgh
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.
The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....
Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.
Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
17.06.2019 | Information Technology
17.06.2019 | Earth Sciences
17.06.2019 | Ecology, The Environment and Conservation