Explain the importance of fossils in deciding evolutionary relationships.

(N/A) Fossils are the preserved remains or traces of organisms that lived in the past. They serve as crucial evidence for evolution by revealing the characteristics of ancient life forms and the gradual changes that led to the development of modern species.
To understand their importance in determining evolutionary history,consider the following example:
$1$. Approximately $100$ million years ago,invertebrates died and were buried in sediment,which eventually turned into sedimentary rock.
$2$. Millions of years later,dinosaurs died in the same area,and their remains were buried in a new layer of sediment on top of the older rock. This layer also fossilized.
$3$. Much later,horse-like creatures died in the same region,and their fossils formed in a layer above the dinosaur fossils.
$4$. Over time,geological processes like soil erosion or flooding may expose the upper layers containing the horse-like fossils.
If scientists excavate deeper into the earth at this site,they will find the dinosaur fossils,and deeper still,the invertebrate fossils. By analyzing these layers,scientists can conclude that horse-like animals evolved more recently than dinosaurs,which in turn evolved after the invertebrates. Thus,fossils found closer to the surface are generally more recent than those found in deeper geological strata.