Influences on Darwin
Student Learning Goals:
- Describe prevailing beliefs before Darwin about the origin of species and the age of the Earth.
- Evaluate Lamarck’s hypothesis about how species change.
- Analyze the impact of Lyell’s Principles of Geology on Darwin’s work.
- Evaluate the influence of Malthus’ ideas about human population on Darwin’s thinking.
- Discuss the relationship between Alfred Russel Wallace and Charles Darwin.
- Know the influence De Vries had on evolution.
How do structures like the Cathedral Rock in Sedona, AZ form?
Though Arizona was not on Darwin's travel plans, the work of others that saw and studied Earth's changing landscape influenced him. One geologist, Charles Lyell, proposed that gradual geological processes have shaped Earth’s surface, inferring that Earth must be far older than most people believed. How else could structures like those shown here develop? If in fact Earth was much older then just 6,000 years, Darwin believed there would have been plenty of time for evolution to occur.
Influences on Darwin
Standing on the Shoulders of Giants
Evolution, like all of science, builds on previous work and often on the work of others. Darwin’s theory was a product not only of his own intellect, but also of the times in which he lived and the ideas of earlier great thinkers. Some of these ideas influenced Darwin’s perspective during his five years on the Beagle; many contributed to his thinking after the voyage. Not until 23 years after he returned to England did Darwin solidify his thoughts and evidence to publish his theory. The foundation of evolutionary biology, On the Origin of Species, was published on 24 November 1859.
Before Darwin, most people believed that all species were created at the same time and remained unchanged throughout history. History, they thought, reached back just 6,000 years; which was thought to be Earth's age in the 1800s.
Jean Baptiste Lamarck
One of the first scientists to explore change in species was Jean Baptiste Lamarck (Figure 2). Lamarck believed that organisms improve traits through increased use and then pass the improved feature on to their offspring. According to this idea of inheritance of acquired traits, giraffes have long necks because early giraffes stretched their necks to reach tall trees and then passed the longer necks on to their calves, as shown in Figure 3 . This attempt to explain adaptation was popular during the 19th century and undoubtedly influenced Darwin’s thinking. Although Lamarck's proposal that species change to adapt to their surroundings, evidence does not support inheritance of acquired traits. You can weight-train for years, but unless your children train as hard as you did, their muscles will never match yours! Darwin’s explanation for giraffes’ necks will be discussed later.
Though Arizona was not on Darwin's travel plans, the work of others that saw and studied Earth's changing landscape influenced him. One geologist, Charles Lyell, proposed that gradual geological processes have shaped Earth’s surface, inferring that Earth must be far older than most people believed. How else could structures like those shown here develop? If in fact Earth was much older then just 6,000 years, Darwin believed there would have been plenty of time for evolution to occur.
Influences on Darwin
Standing on the Shoulders of Giants
Evolution, like all of science, builds on previous work and often on the work of others. Darwin’s theory was a product not only of his own intellect, but also of the times in which he lived and the ideas of earlier great thinkers. Some of these ideas influenced Darwin’s perspective during his five years on the Beagle; many contributed to his thinking after the voyage. Not until 23 years after he returned to England did Darwin solidify his thoughts and evidence to publish his theory. The foundation of evolutionary biology, On the Origin of Species, was published on 24 November 1859.
Before Darwin, most people believed that all species were created at the same time and remained unchanged throughout history. History, they thought, reached back just 6,000 years; which was thought to be Earth's age in the 1800s.
Jean Baptiste Lamarck
One of the first scientists to explore change in species was Jean Baptiste Lamarck (Figure 2). Lamarck believed that organisms improve traits through increased use and then pass the improved feature on to their offspring. According to this idea of inheritance of acquired traits, giraffes have long necks because early giraffes stretched their necks to reach tall trees and then passed the longer necks on to their calves, as shown in Figure 3 . This attempt to explain adaptation was popular during the 19th century and undoubtedly influenced Darwin’s thinking. Although Lamarck's proposal that species change to adapt to their surroundings, evidence does not support inheritance of acquired traits. You can weight-train for years, but unless your children train as hard as you did, their muscles will never match yours! Darwin’s explanation for giraffes’ necks will be discussed later.
Fig. 3: According to Lamarck’s idea of inheritance of acquired characteristics, giraffes have long necks because earlier giraffes stretched their necks to reach tall trees and then passed their lengthened necks down to their calves. Evidence does not support this hypothesis, but many credit Lamarck for advancing the idea that species develop and change.
Charles Lyell
Much as Lamarck questioned the idea that species do not change, Charles Lyell (Figure 4) believed that Earth was much older than 6,000 years old. In his book Principles of Geology, first published in 1830, he recorded detailed observations of both rocks and fossils and used present patterns and processes as keys to past events. He concluded that many small changes over long periods of time built today’s landscapes and that the Earth must be far older than most people believed. Captain Fitz Roy gave Darwin a copy of Principles of Geology just before the Beagle left England and Darwin “saw through [Lyell’s] eyes” during the voyage. Darwin’s theory that present species developed gradually over long periods of time reflects Lyell’s influence. Lyell was a close and influential friend of Charles Darwin.
Much as Lamarck questioned the idea that species do not change, Charles Lyell (Figure 4) believed that Earth was much older than 6,000 years old. In his book Principles of Geology, first published in 1830, he recorded detailed observations of both rocks and fossils and used present patterns and processes as keys to past events. He concluded that many small changes over long periods of time built today’s landscapes and that the Earth must be far older than most people believed. Captain Fitz Roy gave Darwin a copy of Principles of Geology just before the Beagle left England and Darwin “saw through [Lyell’s] eyes” during the voyage. Darwin’s theory that present species developed gradually over long periods of time reflects Lyell’s influence. Lyell was a close and influential friend of Charles Darwin.
Thomas Malthus
Darwin’s idea that individuals in a population compete for resources came from reading Thomas Malthus. Malthus' six editions of An Essay on the Principle of Population, published from 1798 to 1826, observed that sooner or later populations are controlled by famine and disease. Malthus described a human “struggle for existence”, due to exponential population growth and limited food. Darwin thought that animal and plant populations might have similarly limited resources. If so, offspring who were better suited to their environment would be more likely to survive, while those less “fit” would perish.
Darwin’s idea that individuals in a population compete for resources came from reading Thomas Malthus. Malthus' six editions of An Essay on the Principle of Population, published from 1798 to 1826, observed that sooner or later populations are controlled by famine and disease. Malthus described a human “struggle for existence”, due to exponential population growth and limited food. Darwin thought that animal and plant populations might have similarly limited resources. If so, offspring who were better suited to their environment would be more likely to survive, while those less “fit” would perish.
Artificial Selection (by Breeders & Farmers)
Breeders of pigeons, dogs, and cattle inspired Darwin’s ideas about selection. By choosing which animals reproduced, breeders and/or farmers could achieve remarkable changes and diversity in a relatively short time. Variations in traits were clearly abundant and heritable. In fact, in March 1855, Darwin actually became a pigeon fancier and set up a breeding loft at his home.
Darwin though that if pigeon breeders could, in a relatively short time, artificially create varieties as different as Fantails and Swallows or Pouters and Frillbacks, what would prevent nature from naturally doing the same? And, given millions of years, wasn't it possible that a pigeon could be turned into something so radically different that it would no longer be called a pigeon, or even a bird? Couldn't the same be true for any other type of animal? Darwin referred to selective breeding as artificial selection. His observations of how artificial selection worked helped him to develop his concept of natural selection (Figure 5).
Breeders of pigeons, dogs, and cattle inspired Darwin’s ideas about selection. By choosing which animals reproduced, breeders and/or farmers could achieve remarkable changes and diversity in a relatively short time. Variations in traits were clearly abundant and heritable. In fact, in March 1855, Darwin actually became a pigeon fancier and set up a breeding loft at his home.
Darwin though that if pigeon breeders could, in a relatively short time, artificially create varieties as different as Fantails and Swallows or Pouters and Frillbacks, what would prevent nature from naturally doing the same? And, given millions of years, wasn't it possible that a pigeon could be turned into something so radically different that it would no longer be called a pigeon, or even a bird? Couldn't the same be true for any other type of animal? Darwin referred to selective breeding as artificial selection. His observations of how artificial selection worked helped him to develop his concept of natural selection (Figure 5).
Hugo de Vries
Hugo De Vries (born February 16, 1848, Haarlem, Netherlands—died May 21, 1935, near Amsterdam), Dutch botanist and geneticist who introduced the experimental study of organic evolution.
De Vries became a professor at the University of Amsterdam in 1878, serving there until 1918. In 1886 de Vries noticed wild varieties of the evening primrose (Oenothera lamarckiana) that differed markedly from the original plant species. This suggested to de Vries that evolution might be studied by a new, experimental method rather than by the old method of observation and inference. He discovered in his cultivation of the evening primrose new forms or varieties appearing randomly among the host of ordinary specimens. He gave the name mutations to these phenomena, now known as the Mutation Theory, which he showed that genetic changes arise suddenly, as distinct from Darwin’s variation of species through natural selection. De Vries believed these varieties to be an example of an evolution that could be studied experimentally to understand evolution as a series of abrupt changes radical enough to bring new species into existence in a single leap.
Although de Vries did not directly influence Darwin's Theories of Evolution, de Vries' Mutation Theory added supporting evidence that evolution is not only influenced Darwin's theory of natural selection, but also by random genetic changes occurring within a population.
Hugo De Vries (born February 16, 1848, Haarlem, Netherlands—died May 21, 1935, near Amsterdam), Dutch botanist and geneticist who introduced the experimental study of organic evolution.
De Vries became a professor at the University of Amsterdam in 1878, serving there until 1918. In 1886 de Vries noticed wild varieties of the evening primrose (Oenothera lamarckiana) that differed markedly from the original plant species. This suggested to de Vries that evolution might be studied by a new, experimental method rather than by the old method of observation and inference. He discovered in his cultivation of the evening primrose new forms or varieties appearing randomly among the host of ordinary specimens. He gave the name mutations to these phenomena, now known as the Mutation Theory, which he showed that genetic changes arise suddenly, as distinct from Darwin’s variation of species through natural selection. De Vries believed these varieties to be an example of an evolution that could be studied experimentally to understand evolution as a series of abrupt changes radical enough to bring new species into existence in a single leap.
Although de Vries did not directly influence Darwin's Theories of Evolution, de Vries' Mutation Theory added supporting evidence that evolution is not only influenced Darwin's theory of natural selection, but also by random genetic changes occurring within a population.
Credits go CK-12 and Britannica