How long have people been debating the idea of evolution?

How does the study of genetic disorders such as pku biologists understand normal alleles?

The kind of fertilization found in the majority of aquatic animals is (internal or external) fertilization.

Why is earth's outer core hotter than earth’s oceanic crust? earth’s oceanic crust is denser than earth’s outer core is. earth’s oceanic crust has lava flowing from the mantle. earth’s outer core has a composition of solid iron and nickel. earth’s outer core is deeper within earth than oceanic crust is.