by Richard William Nelson | Jan 20, 2026
Adaptation is the fifth principle driving Charles Darwin’s theory, with the long-necked giraffe once serving as a classic example. Natural selection is contingent on cumulative adaptive changes over long periods of time. In The Origin of Species, Darwin wrote –
“The structure of each part of each species, for whatever purpose it may serve, is the sum of many inherited changes, through which the species has passed during its successive adaptations.”
Two key twentieth-century contributors, Ernst Mayr and Yuri Filipchenko, framed a scientific understanding of adaptation in Earth’s biosphere.
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by Richard William Nelson | Aug 20, 2025
Time is the fourth principle driving Charles Darwin’s theory of evolution, “by means of natural selection.” As with the other four principles, time—specifically, the timeframes of Earth’s history—challenges Darwin’s theory of “slight, successive” changes.
The theory of natural selection is contingent on extended periods of time. In The Origin of Species, Darwin wrote –
“I do believe that natural selection will generally act very slowly, only at long intervals of time.”
In this post, the history and current understandings of popular evolution timeframes are examined. “Timeframe” is used interchangeably with modern concepts of timelines and timescales.
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by Richard William Nelson | Feb 19, 2025
Charles Darwin envisioned life on Earth as developing over long periods of time through natural selection. In The Origin of Species, Darwin varyingly restated his vision, for example –
“I do believe that natural selection will generally act very slowly, only at long intervals of time.”
Time is the fourth of natural selection’s five principles, developed by Niles Eldredge (pictured right below) at the American Museum of Natural History. He encapsulated these five principles in the acronym V.I.S.T.A.
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by Richard William Nelson | Sep 7, 2024
Selection is the third of the five principles of natural selection, codified with the letters V.I.S.T.A. Charles Darwin was the first to introduce the term “selection” as a causal evolutionary principle. In The Origin of Species, Darwin wrote –
“Over all these causes of Change I am convinced that the accumulative action of Selection, whether applied methodically and more quickly, or unconsciously and more slowly, but more efficiently, is by far the predominant Power.”
To explain selection, Darwin drew a parallel between a breeder’s selection process and natural selection, including pigeon breeding (pictured above) as an example. At the time, breeding pigeons was a prestigious pastime for the elite.
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by Richard William Nelson | Jul 13, 2023
Evolution centers on offering a natural explanation to account for Earth’s vast and diverse biosphere. A core measure of evolution is the concept of species, the prime number of evolution. The importance of the concept is highlighted in the title of Charles Darwin’s bestseller —
“On the Origin of Species by Means of Natural Selection”
One of modern biology’s principal functions includes the naming, grouping, and defining of species. However, exploring the history of the term opens a fascinating window into the checkered history of Darwin’s theory of natural selection.
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Adaptation is the fifth principle driving Charles Darwin’s theory, with the long-necked giraffe once serving as a classic example. Natural selection is contingent on cumulative adaptive changes over long periods of time. In The Origin of Species, Darwin wrote –
