The vast majority of animals that ever existed are now extinct, but Tereza Jezkova and John Wiens wondered which variables were most important in driving the diversification of species that exist today. Why are there so many species in some phyla, such as Cnidaria (see photo), but so few in others, such as Ctenophora? Draw a horizontal axis to represent the number of species within phyla using a logarithmic scale (1, 10, 100, 1000 species, etc.). Then use Table 30.1 to map seven representative phyla from small to large at intervals of about an order of magnitude on this scale.

Verified step by step guidance

1. Draw a horizontal axis and label it 'Number of Species within Phyla' using a logarithmic scale (1, 10, 100, 1000, 10000, 100000).
2. Identify the seven representative phyla from the provided bar graph: Sponges, Mollusks, Flatworms, Jellyfish (Cnidaria), Chordates, Roundworms, and Arthropods.
3. Map the number of species for each phylum on the logarithmic scale based on the bar graph data: Sponges (~10,000), Mollusks (~80,000), Flatworms (~20,000), Jellyfish (Cnidaria) (~10,000), Chordates (~60,000), Roundworms (~30,000), Arthropods (~90,000).
4. Plot each phylum on the horizontal axis at intervals of about an order of magnitude: Sponges (10^4), Mollusks (8x10^4), Flatworms (2x10^4), Jellyfish (Cnidaria) (10^4), Chordates (6x10^4), Roundworms (3x10^4), Arthropods (9x10^4).
5. Label each point on the graph with the corresponding phylum name.