This rock on a Pacific coast beach was weathered over thousands of years, and revealed within its sandstone this harder rock which is likely the fossilized remnant of an ancient coral or related creature. It reminded me that we have these fossils within our own DNA.
It was recently revealed that up to 2-3 percent of the genome of non-Africans have Neanderthal genes and a third human species, the Denisovans were found to be lurking. But this is just the recent past, being merely 20-50,000 year distant.
I was reviewing the lymphatic system in our bodies –it is the often overlooked third blood vessel system after arteries and veins, and its roots are older than either being present in our distant relations, the tunicates. Where arteries and veins are connected in a closed loop, the lymphatics are open to the extracellular space, and once in the past, to the ocean. This link to primitive chordates goes back nearly half a billion years.
They are now saying that there may be millions if not billions of earth like planets around middle aged stars, even in just this galaxy alone. Over cosmic time, and given those numbers of planets, it is a statistical certainty that life is common and not rare.
This feeling that life is a rare circumstance in an otherwise sterile universe has its roots in the narcissism of an idiot. The assumption that our clever ideas, petty jealousies, and unending appetites are unique is from the cosmic hayseed’s provincialism that gives certainty to the notion that a hundred years is a long time and that the universe disappears when you shut your eyes.
Starting from a single cell, our complexity is layered on like a gobstopper. Our DNA is not just a blueprint, but also a blog of life over three billion years. We are living fossils.
The fossil pictured above is Tiktaalik, a lobed finned fish from the Devonian. What it has that is unique is that it has a humerus, radius, and ulna along with shoulder, elbow and wrist that is the rubrik for all land vertebrates. The pattern of one bone with two distal bones are what we experience every time we eat chicken wings, and we owe it to this class of fish which may be a direct ancestor or closely related to it.