Scientists have sequenced the genome of sea urchin, and found that the spiny invertebrate are part-human:
Scientists who have sequenced the genome of the sea urchin say these brainless and limbless invertebrates are surprisingly similar to humans.
They found that the California purple sea urchin (Strongylocentrotus purpuratus) genome has 23,300 genes.
And it shares 7077 of them with humans.
The genetic ties are far closer than scientists expect and make the sea urchin a closer genetic cousin of humans than the worm or fruit fly, according to the study in today's issue of the journal Science.
Or, maybe we're all part sea-urchin. This would explain the prickly temperaments of some people: Link