It's A. Fewer anaerobic species
Many of the organisms that had existed on the earth left no fossils because most of them can not meet the conditions that must be fulfilled before fossils can form. For fossils formation to occur, the organism soft tissue must decay leaving behind the hard part [majorly bone] in the sediment. Overtime, layers of sediment have to build up and pressed down on the buried remains. As time goes on, water and mineral seeped into the remains and form crystals.
Habitat isolation is likely to be most relevant in the case of trumpeters in the Amazon basin.
If trumpeters can not cross rivers, then they would be able to mate with trumpeters on the same side of the river but not on the other side- a form of prezygotic isolation.
what are trumpeters?
The term "trumpeter" comes from the deep, booming territorial call of these chicken-sized, long-necked, hunch-backed, small-headed, short-tailed, dark-plumed, long-legged birds that wander the jungle floors of South America.The land of South America that now the Amazon River and its tributaries drain is recognized as the Amazon basin.
learn more about Amazon basin here:-
brainly.com/question/14229038
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