Changes in the environment can modify the amount of natural resources available for the populations to survive.
Changes in the environment can separate a population and cause changes so intense that it prevents members of the population from establishing crossings.
Explanation:
As we know, changes in the environment can be caused by the manipulation of human beings or even by natural processes and phenomena of nature. What matters is that these changes always provide an environmental impact that can be beneficial or harmful, but will always affect populations.
Environmental impacts can cause changes in the environment that will modify the amount of environmental resources (food, water, habitat) needed for the populations to survive. The reduction of these environmental resources can cause an increase in the mortality rate of populations.
In addition, environmental changes can separate a population and cause an evolution in each separate part to the point of generating new species and not allowing members of each species to establish crosses.
Cnidarians represent a more complex level of organization than Porifera. They possess outer and inner tissue layers that sandwich a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion.
