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, developed the scientific framework for understanding the role 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.”
In explaining 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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by Richard William Nelson | Jan 3, 2023
Mendel rescued Darwin’s theory of natural selection early in the twentieth century – to a point.
By the end of the nineteenth century, Charles Darwin’s influence had continued to deteriorate, stemming from his obsolete theory of inheritance.
In the search for a scientifically valid theory, scientists, early in the twentieth century, rediscovered Gregor Mendel’s genetic inheritance theory, which had been published thirty years earlier.
Mendel’s theory delivered what Darwin missed – a scientifically valid theory of inheritance capable of driving evolution.
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by Richard William Nelson | Nov 8, 2022
Inheritance is known as the second of Charles Darwin’s five principles of natural selection described in The Origin of Species. While Darwin knew that inheritance plays a crucial role in natural selection, he was conflicted over how it works, noting –
“The laws governing inheritance are for the most part unknown.”
Niles Eldredge, of the American Museum of Natural History, codified the five principles of natural selection, variation, inheritance, selection, time, and adaptation, with the letters V.I.S.T.A.
In 1837, nearly twenty years before publishing The Origin of Species, Darwin drew his first sketch linking inheritance to speciation (pictured left).
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by Richard William Nelson | Aug 17, 2022
Variation is the foundation of the theory of natural selection presented by Charles Darwin in The Origin of Species. Darwin argued –
“Natural Selection acts exclusively by the preservation and accumulation of variations,”
Variation is the first of the five natural selection principles, codified with the letters V.I.S.T.A. Niles Eldredge, a paleontologist at the American Museum of Natural History, introduced the code to frame Darwin’s theory.
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by Richard William Nelson | May 27, 2022
Logic and science play crucial roles in understanding how nature works. Importantly, however, there are distinct types of logic and methods in science. Selecting the appropriate type of logic and science is crucial for developing scientifically valid explanations.
Charles Darwin applied various logic and scientific methods in his life-long quest to explain how Earth’s biosphere works. The story of his quest is fascinating, giving insight into how the interplay of logic and science still influences modern evolution research.
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by Richard William Nelson | Jan 13, 2022
Three years into the pandemic, the origin of COVID-19 is still controversial. Two leading theories are under investigation: natural selection process or genetically engineered – each with vastly different implications. The phylogenetics of coronaviruses is the key to the COVID-19 origin dilemma and gaining insights into the theory of evolution.
Coronaviruses are RNA, not DNA viruses. RNA viruses are associated with causing the common cold, influenza, mumps, and measles; coronaviruses in humans can cause respiratory tract infections ranging from no symptoms, mild symptoms to a cytokine storm resulting in organ failure and death in humans.
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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 –
Mendel rescued Darwin’s theory of 
Three years into the pandemic, the origin of 