This essay treats the most celebrated story in the extreme simplification in an adult parasite - in the interests of illuminating, reconciling, and, perhaps, even resolving two major biases that have so hindered our understanding of natural history: the misequation of evolution with progress, and the undervaluing of an organism by considering only its adult form and not the entire life cycle.
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Triumph of the Root-Heads, p. 356Stephen Jay Gould
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Consider one of the standard "laments" or "stories of wonder" in conventional tales of natural history: the mayfly that lives but a single day (a sadness even recorded in the technical name for this biological group - Ephemoptera). Yes, the adult fly may enjoy only a moment in the sun, but we should honor the entire life cycle and recognize that the larvae, or juvenile stages, live and develop for months. Larvae are not mere preparations for a brief adulthood. We might better read the entire life cycle as a division of labor, with larvae as feeding and growing stages, and the adult as a short-lived reproductive machine. In this sense, we could well view the adult fly's day as the larva's clever and transient device for making a new generation of truly fundamental feeders.
Stephen Jay Gould
What constitutes the primordium of the adult parasite [ Rhizocephala]? What can be injected through the narrow opening of the dart's hypodermic device? ...Imagine going through such complexity as nauplius, cyprid, and kentrogon - and then paring yourself down to just a few cells for a quick and hazardous transition to the adult stage. What a minimal bridge at such a crucial transition! ...But other species have achieved the ultimate reduction to a single cell! The dart injects just one cell into the host's interior, and the two parts of the life cyle maintain their indispensable continuity by an absolutely minimal connection - as though, within the rhizocephalan life cycle, nature has inserted a stage analogous to the fertilized egg that establishes minimal connection between generations in ordinary sexual organisms.
Stephen Jay Gould
"Let me tell you the story of the most successful organism of all time: this is the story of the parasite. ... Early on, evolution branched into two distinct paths: independent organisms—those that exist on their own in the natural world—and parasites—organisms that live on other organisms. And it was, by far, the parasites that proved the more successful of the two branches. Today, for every independent organism in nature, there exist three parasites. ... These two strains of evolution have been locked in a primordial arms race, constantly evolving to best each other for supremacy of this planet. As parasites evolve to perfect their systems against a species of host, the host evolves to evade their attack. Scientists call this theory of an eternal genetic struggle the Red Queen Hypothesis—a name taken from Lewis Carroll's Through the Looking Glass."
Daniel Suarez
I began to become an adult when I was 24 and got married and had children. That matures you, but I wouldn't say I was fully an adult until I was in my forties. The trouble with the whole adult debate is that if you're asking 18-year-olds to go out and fight wars for you then you can't deny them adult rights even though in sorts of other ways they wouldn't qualify until they were about 25. These days adolescence stretches much further into adulthood than it used to. There's no longer any encouragement to be mature.
J. G. Ballard
The parasite has somehow evolved to turn off the host's defenses, presumably by disarming the crab's immune response with some chemical trickery that fools the host into accepting the parasite as part of itself. ...The adult parasite castrates the host, not by directly eating the gonadal tissue, but by some unknown mechanism probably involving penetration of the interna's roots around and into the crab's nervous system.
Stephen Jay Gould
Gould, Stephen Jay
Govorov, Leonid
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