Biological research continues to enhance the plausibility of front-loading evolution.

Sea urchins may be blind, but they have the same genes that help people see, as well as genes for a sense of smell and one of the most complicated immune systems in the animal world, researchers reported on Thursday.

They also have genes associated with diseases such as Huntington’s and muscular dystrophy, offering new routes to understanding illnesses, the researchers write in Friday’s issue of the journal Science.

They found that the urchin has about 979 genes for proteins that sense light and odors — similar to what is found in vertebrates that actually do see and smell things. How the sea urchin uses them is not yet clear.

Like people, sea urchins have many immune genes that are active in the gut, which may help in coping with symbiotic bacteria that help digest food.

“It is one thing to be able to recognize all bacteria and get rid of all of them. It is another thing to maintain that in a complex way that you don’t kill all of them,” Rast said in a telephone interview.

Vertebrates have adaptive immune systems as well as innate immune systems that attack invaders without necessarily recognizing them, but invertebrates do not.

Urchins appear to have the genetic predecessors to the adaptive immune system — the antibodies and T-cells that can change and respond to new germs, the study showed.

The significance of all this will become more clear after reading The Design Matrix.