sea squirt


An adult sea squirt.

Announcement cards, graduation gowns, caps, tassels, keyrings, yearbook, senior T-shirts, senior sweatpants, senior water bottles. A whole assortment of commercial memorabilia are vying for my attention — or rather my checkbook. It is my son’s senior year. Graduation is not only the celebration of accomplishment after many years of school, it also marks the beginning of a new phase of life. It is only natural that as parents we ponder many questions: What will our children do when they grow up? Will they leave the nest now and set out on their own? Did we give them the skills to succeed in the world? Will they find happiness?

According to some psychology websites I looked into this morning, this human anxiety, the fear of failure, is a remnant of the human evolution from the status as  prey. In the early days of human evolution our ancestors had many worries that we don’t have to think about in todays life. They lived in close proximity to large predators that had no objection to human for dinner, expecially when it came to small, hairless, defenseless primate babies they viewed those as a tasty morsel.

Thus, we evolved to worry about our children and live with an ever-present fear of impending disaster. In fact, the roots of feeling defenseless are so deep that they have persisted to be part of us even in todays world, where arguably the greatest dangers to our existence are of our own making.

There is a group of ocean animals that evolved in much the opposite direction. In sea squirts an egg hatches into a larva equipped with a small rod that resembles a spine and helps with swimming, a simple eye, and a brain to process the information from that eye as well as coordinate the swimming. Once the larva passes its early life stages and finds a suitable place to settle, it gives up any worries or control over the rest of its life and digests its brain. From then on the adult lives in one place, eats and produces gametes. This life style has worked for sea squirts for 500 million years. No brains, no graduation, no society, no politics, just eat and reproduce.

Jellyfish have been around as long or even longer than the sea squirts. There is a big difference between these two ancient life forms. The sea squirts are thought to be the first step in evolution towards the development of a spine and are actually grouped right next to the chordates into the phylum hemichordates. Sea squirts are more closely related to us than they are to the jellyfishes.

The jellies have a few nerves but nothing resembling a brain. Yet, as brainless, heartless, boneless creatures they have been around longer than most multicellular life forms and they are thriving in todays oceans better than many of their more highly evolved and much more complicated distant relatives.

Jellyfish are not affected by ocean acidification, have no trouble adapting to warming ocean temperatures, and overfishing just takes away the competition for their food. They may have no brains, but they are well equipped to succeed in today’s world ocean.

It appears that with the evolution of the highly complex human brain our definition of success has also evolved. While many parents may wish to one day be grandparents, we usually hope for much more and more complex achievements for our kids. Few parents would put their graduates through college only to happily watch them afterwards settle down, digest their brains and spend the rest of their lives eating and reproducing.

Of course, our society and politics have made our lives much more complicated than that, because in our human society there is nothing easy about finding a place to settle, paying for it and heating it, and food will not just float by on the currents either like it does for the sea squirt.

Whenever the trend to bigger brains started, we are now stuck with having to think our way through life. The best we can do for our kids is to help them think for themselves and adjust to the world they find themselves in. Sooner or later every creature has to let go of their offspring and hope for the best, it is just another one of those amazing facts of life.

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