A researcher performed an analysis of the elemental composition of several fish species living in the same body of water. The amount (in parts per million) of iron (Fe), calcium (Ca), potassium (K), sodium (Na), and magnesium (Mg) found in each species is shown in the table. Species Fe Ca K Na Mg
Species A 55.70 179.51 107.94 45.39 33.89
Species B 23.74 134.16 105.19 45.10 33.38
Species C 67.18 785.18 103.60 42.71 32.45
Species D 30.09 457.59 107.97 44.68 33.84

Based on this data, identify which elements are found in similar concentrations across all species of fish tested. Explain how this data provides support for the hypothesis that all four species of fish descended from a common ancestor.