The PNS helps to maintain internal balance, or "homeostasis," by the Parasympathetic division of the Autonomic Nervous System (ANS). Sometimes referred to as the "rest and digest" system, the Parasympathetics keep our internal activities regular throughout the day and night, such as a steady heart rate, slow breathing, digestion of food, filtration of blood, and excretion of wastes.
Pistil,carpel,ovary,<span>ovules</span>
We have shelter and food.
Answer:
Positive natural selection.
Explanation:
The positive natural selection is a type of natural selection that increases the frequency of an allele or trait when it is advantageous for the population. What happened in the example is that the mouth with the slight change in morphology (trait) was more advantageous for the population in the south in relation to the ancestral morphology (still preserved in the population in the north), and therefore its frequency increased. This, in turn, is due to the fact that the food (prey) is not the same in the two habitats (north and south). The specific prey in the south, caused the new morphology to be selected, (increasing the frequency of individuals with the new mouth), becasue probably that trait allows the trouts in the south to hunt more effectively.
Answer
La corteza terrestre temprana apareció hace aproximadamente 4.500 millones de años, después de las últimas etapas de acreción planetaria.