Embryological studies suggest that the most ancient chordates were related to the ancestors of

Fossils can only be formed when? if mud, silt or tar is in the area to preserve the fossil ierosion does not occur and allows the fossil to form oxygen and microorganisms cannot decay the bones the area is dry and does not contain mud or silt

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

If there is another new infectious disease somewhere in the world, what do you think canadian officials should do