Hypothesis-vertebrates evolved from echinoderms

Question

Suppose a scientist is testing the hypothesis which vertebrates evolved from echinoderms. Having a research object a lately found protochordate species, what is an illustration of a discovery which would weaken the hypothesis? What is an illustration of a discovery which would strengthen it?

Answer 1

Hypothesis to be tested: Vertebrates developed from echinoderms. Testing material: A recently found protochordate species (that is, a vertebrate forerunner). Illustration of weakening observation (which puts the latest protochordate species evolutionarily far from echinoderms): “The new species is protostome”, as opposed to echinoderms, which are deuterostomes. This observation brings the suspicion which deuterostomy in vertebrates is independent in beginning from echinoderms.

Illustration of strengthening observation (which nears the latest protochordate species to echinoderms): “The latest species has secondary radial symmetry”, identical to echinoderms. This observation forms stronger the hypothesis which echinoderms and vertebrates are relatives. (This item exhibits how science works, starting with the placement of hypothesis and additional observational testing.)