Allopatric speciation, also referred to as geographic speciation, is a method of the formation of new species due to isolation of the species from one another through geographic means.
The first step in this process is geographic isolation, which means that the original population is divided into two groups due to geographical reasons such as movement of continents or formation of water bodies.
Next, the species are subjected to different selection pressures due to their different environments. Eventually, the gene pool becomes very different for the two species due to the different selection pressures and because they are not allowed to mix.
Finally, after enough time passes, speciation occurs, which means that the two populations cannot breed to form fertile offspring.
Answer:
The correct answer is option D.
Explanation:
Thermohaline circulation is the circulation of currents in the deep ocean due to the density of the water which is controlled by heat and salinity. Water in the ocean posses layers or defined boundaries based on the density which provides driving force to the deep ocean currents.
Formation of these layers is due to the sinking of the cold water in the basin which and ice formation which leaves the salt in the seawater ,therefore, increasing salinity. This increased salinity increases its density and the surface water is replaced by the sinking water causing deep ocean currents.
Thus, option D is the correct answer.
Eccentricity of a body following an elliptical orbit defines how nearly circular the path of the object is. When the eccentricity of an orbiting body increases, it means that the body is moving in the most stretched out path.
The energy that the hawk has taken isn't enough for another animal to get any benefit therefore the pyramid has a limitation.
