Ammonite is a species of shellfish that is used as an index fossil. it has a distinct spiral shell. which statement most likely explains why other species of shellfish that existed around the same period of time are not considered index fossils?
a.
other shellfish did not contain the carbon-14 isotope.
b.
other shellfish were much smaller in size than ammonites.
c.
other shellfish were not as widespread as ammonites.
d.
other shellfish did not have a rigid external body, like ammonites. match each process to where it occurs in the carbon cycle.

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.