In David's own estimate, out of the 12,000–13,000 species of fish known to humans in his day, he and his students had discovered over 2,500 of them. One out of every five in the world, that was.
What drove him to such monumental tasks, to persist and persevere while catastrophes struck, again and again?
He had “a terrifying capacity for convincing himself that what he wanted was right,” writes scholar Luther Spoehr, “His ability to crush those in his path multiplied even as he became convinced that his path was the one of righteousness which led to progress.”
A belief system likely seeded by his youth time idol, the naturalist Louis Agassiz (whose statue stands outside the marine research building commissioned by David at Stanford), whose summer camp inspired David to the field of Ichthyology study.
Agassiz believed there were objective measures about organisms, such as “the complication or simplicity of their structure” or “the character of their relations to the surrounding world,” that could be used to rank organisms in their proper order. Lizards, for example, would score higher than fish because they “bestow greater care upon their offspring.” Parasites, meanwhile, were clear lowlifes, the lot of them. Just look at how they earned their living: they mooched and deceived and freeloaded.
He believed there is a ladder built into nature. A divine hierarchy from bacteria to humans that points objectively toward better. The highest of creatures could fall from their rungs if they weren’t careful, that bad habits could somehow cause a species to physically and cognitively decline.
When Darwin's evolution theory became the zeitgeist of late 19th century, David mashed it with Agassiz’s foggy idea of “degeneration” and ran with it. In a scientific paper, David proposed that the sea squirt, a sedentary sac of a filter feeder, had once been a higher fish but had “degraded” into its current form due to a combination of “idleness, inactivity and dependence.”
David was one of the first to bring Eugenics ideas that started in England to America. As early as the 1880s, decades before most American eugenicists got the fever, David had begun to tuck these ideas into his lectures at Indiana University, informing students that traits like “pauperism” and “degeneracy” were heritable and thus could be “exterminated just as swamps are drained.”
He published his first pro-eugenics article in 1898 and followed it with a flurry of books advocating for the cleansing of the gene pool. He made stops at churches and almshouses, where he’d warn the devoted staffs about the dangers of their work fomenting, as he claimed it did, “the survival of the unfit.”
In 1907, a few of his friends from Bloomington successfully legalized forced eugenic sterilization in Indiana—the first such law not just in the country but in the world. Two years later, David helped get it passed in California. His commitment to the cause apparent, he was asked to chair the Eugenics Committee of the American Breeders Association. He eagerly accepted.
Now back to the fish story, and a bit evolutionary mumbo jumbo.
How do evolutionary biologists classify creatures found on earth? Starting in 1990s, "cladistic" method is the most common one used. What does cladistic method do? Simply put, it categorizes organisms in groups ("clades") based on the most recent common ancestor.
For example, if you want to talk about group "vertebrates", that includes all creatures with a backbone, then snakes are in, worms are out. Group "mammals"? It must include every single descendant of that first creature able to make milk. Cats, dogs, whales, all good. No reptiles allowed!
Quiz: A cow. A salmon. A lungfish. Which of these things is not like the other?
If you could, for a moment, allow yourself not be blinded by the outer look of these creatures (such as the scales of the salmon and the lungfish) but focus on their shared evolutionary traits, then you would begin to notice: the lungfish and the cow both have lung-like organs that allow them to breathe air while the salmon does not; the lungfish and the cow both have an epiglottis (a small flap of skin that covers the windpipe) while the salmon is epiglottis-less; and the lungfish’s heart is structured more like a cow’s than a salmon’s, etc., etc., etc. All leading to the conclusion that the lungfish is more closely related to the cow than to the salmon.
Using method like this, taxonomists conclude that fish, as a legitimate category of creature, do not exist.
We human mind intuitively and summarily groups all creatures living in water with scaled skin, swinging fins, sleek body as one kind and call them fish, but by that same logic, we should treat all creatures living in mountains, for example, mountain goats, mountain toads, mountain eagles, and mountain men, as one kind and call them one same name, but we don't.
To conclude the story, let's give some equal opportunity time to Darwin:
Contrary to David and Agassiz's assertion of a divine hierarchy from bacteria to humans that points objectively toward better, Darwin sees no ladder in nature.
Nature doesn’t jump, he says. Species—and indeed all those fussy ranks taxonomists believed to be immutable in nature (genus, family, order, class, etc.)—were human inventions. Useful but arbitrary lines we draw around an ever-evolving flow of life for our convenience. Nature has no edges, no hard lines. To get stuck on a single hierarchy is to miss the bigger picture, the messy truth of nature, the “whole machinery of life.”
And what does Darwin say is the best way of building a strong species? Variation. In nearly every chapter of "Origin of Species," Darwin hails the power of “Variation.” He marvels over how diverse gene pools are healthier and stronger, how inter-crossing between different types of individuals gives more “vigor and fertility” to their offspring, how even worms and plants that can produce perfect replicas of themselves are equipped for sex, for introducing variety back into the gene pool.
And maybe every little interaction between creatures, sentient ones in particular—the affection, good will, compassion..., makes life bind closer, jell better,
evolve higher, proves that we exist, with or without label, categorizable or not!
* This 4-part write-up is based on the book "Why Fish Don't Exist" by Lulu Miller I recently finished reading. Hope it gives you enough distraction from the lockdown and endless bombardment of the corona virus news we are all facing now. Cheers!
