Which organism evolved before the others in geologic time?



mammals

amphibians

reptiles

**fish

Which type of organism evolved later than the others?


**mammals

amphibians

reptiles

fish

correct

To determine which organism evolved before the others in geologic time, it is important to understand the concept of the fossil record and the principles of evolutionary biology.

The fossil record provides valuable evidence about the timing of the evolution of different organisms. Fossils are the remains or traces of once-living organisms that have been preserved in various geological layers of the Earth. By studying the relative positions of these fossils in the rock layers, scientists can establish the chronological order of their appearance.

In the given options, the earliest organism to evolve in geologic time is **fish**. This is because fish are considered to be one of the earliest vertebrates to appear in the fossil record. Fossil evidence shows that fish evolved millions of years before amphibians, reptiles, and mammals.

On the other hand, to determine which type of organism evolved later than the others, we need to consider the same principles. In this case, **mammals** evolved later than amphibians, reptiles, and fish. Mammals are characterized by features such as hair or fur and mammary glands for milk production. Fossil evidence shows that mammals evolved from a group of reptilian ancestors and appeared in the geologic record much later compared to amphibians, reptiles, and fish.

So, in summary, fish evolved before amphibians, reptiles, and mammals in geologic time, while mammals evolved later than amphibians, reptiles, and fish.