Evidence of Evolution
The extreme detour of this nerve (about 15 feet in the case of giraffes) is cited as evidence of evolution as opposed to intelligent design. The nerve's route would have been direct in the fish-like ancestors of modern tetrapods, traveling from the brain, past the heart, to the gills (as it does in modern fish). Over the course of evolution, as the neck extended and the heart became lower in the body, the laryngeal nerve was caught on the wrong side of the heart. Natural selection gradually lengthened the nerve by tiny increments to accommodate, resulting in the circuitous route now observed.
Read more about this topic: Recurrent Laryngeal Nerve
Famous quotes containing the words evidence of, evidence and/or evolution:
“In spite of the air of fable ... the public were still not at all disposed to receive it as fable. I thence concluded that the facts of my narrative would prove of such a nature as to carry with them sufficient evidence of their own authenticity.”
—Edgar Allan Poe (1809–1849)
“I don’t know what it is about fecundity that so appalls. I suppose it is the teeming evidence that birth and growth, which we value, are ubiquitous and blind, that life itself is so astonishingly cheap, that nature is as careless as it is bountiful, and that with extravagance goes a crushing waste that will one day include our own cheap lives.”
—Annie Dillard (b. 1945)
“Historians will have to face the fact that natural selection determined the evolution of cultures in the same manner as it did that of species.”
—Konrad Lorenz (1903–1989)