Trilobites Trilobites were crab-like animals
that lived in ancient seas.
Scientists have discovered many
trilobite fossils all over the world.
However, the fossils only appear
in rocks that are at least 250
million years old. In more recent
rocks, their fossils are absent.
1. What conclusion would you
draw about trilobites based on
their appearance and
disappearance in the fossil
record

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Acquired mutations can result from radiation pollution toxins inheritence select all that apply

What must be done to breed dogs for a partical trait