Friday, 27 February 2009

A visit to Charles Naudin's Chile palms at Collioure

Jubaea chilensis

Of seven Jubaeas planted by Charles Naudin in 1869, these are the last survivours. Click on photo for link to site describing these palms.

Charles Victor Naudin, 1815–99

Charles Naudin performed experiments on plant hybridization and theorized about the nature of heredity. A contemporary of Gregor Mendel, Naudin pursued a similar experimental direction. Due to Naudin's lack of statistical analysis, however, along with some unfortunate accidents, Naudin did not present the scientific community with strong evidence of his conclusions, leading to a delay in the realization of the benefits of his experimentation.

The son of a struggling entrepreneur, Naudin graduated from university at Montpellier, France in 1837. He then moved to Paris, finding work as a bookkeeper, tutor, private secretary, and gardener in order to support further study. After obtaining his doctorate from Paris in 1842, he became a teacher. In 1846, Naudin was given an opportunity, joining the herbarium at the Museum of Natural History, and then becoming professor of Zoology at the College Chaptal.

Naudin was forced to resign from these hard won posts almost as soon as he obtained them, due to a severe nervous disorder, which left him deaf, and in constant pain. His academic career seemingly over, Naudin entered an unsettled period, finally settling at Collioure, in 1869, and establishing a small, private experimental garden. He sold seeds and specimens to make a living, while pursuing his interest in experimental horticulture. Naudin's botanical efforts gained reward in 1878, when he was made director of the experimental garden at Antibes, finally finding financial security. However, further tragedies challenged his scientific progress, including the loss of his eyesight and the death of his children.

Despite these setbacks, Naudin managed to perform a number of innovative experiments in acclimatization, economic botany, and most importantly, plant hybridization. Earlier work had suggested that hybrids--crosses between two races, breeds, strains, or varieties--might be a means for the creation of new species. This theory gained new popularity with the work of Charles Darwin. Naudin became interested in the evolutionary nature of hybrids, but altered his views when he observed that most hybrids were infertile, and that such crosses did not seem to survive many generations.

Naudin's experiments led him to conclude that first generation hybrids were uniform in nature, most having a mixture of characteristics from both parents. In subsequent generations from hybrid plants, however, there was great diversity and a strong tendency to revert to one of the parent types. Naudin concluded that nature abhors hybrids, and that within such plants occurred a kind of battle to return to a natural, pure form between the "specific essences" from the parent plants. He argued that hybrids could not result in new species, as the new, mixed forms that appeared in early generations would disappear in later generations, eventually reverting completely to a parental type.

Naudin combined his results into a law of segregation, which bears a strong resemblance to Gregor Mendel's own law of the same name. However, Mendel simplified the problem, focusing on specific traits rather than the plant as a whole, and supported his work with statistical analysis. Naudin's conclusions were based on scientific intuition, and this meant that while he often came to correct assumptions, he could not support them with strong evidence or theory.
Bad weather, poor choice of plants, lack of space and money, and other misfortunes also plagued Naudin's experiments. A virus, which was not identified until the following century infected many of his plants, and gave them unusual characteristics. Accidents such as this led Naudin to follow a number of fruitless paths in his research, and reach false conclusions.

Naudin's ideas were dealt a serious blow when Charles Darwin heavily criticized them. Darwin supported a theory of blended inheritance, in which each parent contributed equally, and where each offspring was still, in some small part, influenced by all previous generations. Eventually, Darwin did incorporate Naudin's ideas into his own work, as the weight of experimental evidence for non-blended inheritance grew. As a result, many of the late nineteenth century theories for heredity became confused and vague, using a hodge-podge of possible methods. It was not until the rediscovery of Mendel's work in the early twentieth century that a more coherent explanation became available, and the early hybridization work of Naudin and others was re-examined gained scientific appreciation.

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