ndividuals with tolerant alleles have growth rates on unpolluted soil and growth rates on mined soils. Therefore, we would expect copper tolerance to be % on mine sites and % on unpolluted sites if natural selection is acting alone. However, index of copper tolerance decreases from the downwind side of the mine. This is example where constrains selection.

the trilobite is used as an index fossil for various geologic time periods as specific types of the trilobites were present in different geological time periods. they are a group of marine arthropods belonging to the class of trilobita.

explanation:

"do a testcross with a homozygous recessive plant."

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?