There are 23 pairs of chromosomes in each cell in a normal adult human.
the atmospheric pressure decreases upwards, hence the inter-molecular attraction between the air molecules decreases or to say that the inter-molecular space increases and the parcel of air expands.
Secondary succession occurs when a natural devastating calamity or event takes place such as hurricane and forest fire. It is often faster compared to primary succession because there are available resources already including soil, roots, seeds and other vegetative organs from plants can be found underground.
Answer:
Stephen Stearns states that natural selection doesn't mean the survival of the fittest organisms, but rather this mechanism is illustrated by the selective reproduction of the fittest. Natural selection can be classified into distinct types, including directional, disruptive and stabilizing selection, which are in turn based on sexual selection. These types of selection are driven by different outcomes that have different dynamics.