Answer:
In the course of evolution mammals are the animals which are evolved recently as compared to other groups such as fish, amphibians, or reptiles.
In addition, fur or hairs on body, mammary glands, middle ear bone, warm-blood, et cetera are the characteristics of mammals.
These characteristics were evolved during the course of evolution; they were not present in ancestral organisms.
However, tail, gill pouches, et cetera are characteristics of our ancestral groups. Thus, characters can be sometimes observed in mammals.
But mammals characteristics can not be observed in organisms which were evolved before mammals such as fishes, amphibians, reptiles, et cetera.
The answer is young child.
Nasal regurgitation it's when the food regurgitates out of the nose.
This is more likely to occur in babies/ young children with some birth defects in the soft palate, or if they have a cleft lip. Those birth defects, usually, get fixed with surgery when they are still children, that's why is less frequent after that age.
Probably the intertidal zone, as I reason the tides would affect life dramatically. High and low tide would affect land and ocean creatures in this zone too often where as the coastal and open oceans have constant properties.
Answer:
The oldest fossils, between 3.5 and 3.8 billion years old, are then accepted as both the first life and prokaryotic.
