What do scientists often use to study macro evolution?

Explanation:sceintissts learnt physics, chemistry and biology and macroevalution

Fossil record is used to study macro evolution.

Explanation:

Macroevolution may be defined as the change above the species level. Fossils are the impressions of dead plants and animals buried under the surface of rocks.

Fossils provide the direct evidence of macroevolution. For example : Paleozoic era was dominated by trilobites, crinoids and brachiopods. Rocks that one part of paleozoic era are now contains the fossils of trilobites, crinoids and brachiopods. These species may either extinct or not common in today's world. Thus, fossil record can be used to study macroevolution.