But he didn't know about genes, did he? I don't know whether he did or didn't. **OK, I looked it up and seems he did not know about genetics. Maybe I am wrong about that. Says the Nat'l Institute of Health USA - "Darwin's theory of natural selection relied critically on the continual production of heritable variation in populations. From his own observations he knew that natural populations contained a wealth of variation, and he had a clear view of how these variants would accumulate in populations under the influence of natural selection. But he did not know how variation was generated, or how traits could be inherited. It is remarkable that his theory of evolution was essentially correct despite his lack of knowledge of the causes of heredity." Maybe I'll read his book because I can't figure what he considered as a wealth of variation in what is called natural populations. I'd have to get more specifics about his thoughts there. Then again, maybe I won't read his book now. I'll see. His original postulates were not always correct anyway, were they? But according to the NIH, seems he didn't know at that point about DNA. if I understood their description. And yes, I have questions about DNA too in reference to "heritable characteristics."
I can understand if you're getting tired of answering my continual questions although I thank you for your continuance, please do not feel obligated to answer, but I do appreciate it. Realizing this now could take a lifetime I can see why scientists can get very, very involved in the details and findings.
You are getting ahead of yourself, YoursTrue.
Of course, Darwin didn’t know about modern genetics and didn’t know about DNA. No one did. Not even Darwin’s contemporary, Gregor Mendel, the pioneer of modern genetics, knew nothing about DNA & RNA.
Science is about progresses and such knowledge occurred over time, meaning scientific knowledge are attained incrementally with discoveries. It applied to every Physical Sciences & Natural Sciences, every branches, fields & subfields, and not just in Evolutionary Biology.
And more importantly. No scientists - back then and now - are not expected to know about everything there are to know. And especially not especially not pioneers in their respective fields.
Darwin, as well as Alfred Russel Wallace, were two pioneers of Natural Selection. They got the theory of Evolution started, providing the general framework of evolution via Natural Selection. Neither of them knew anything about the other evolutionary mechanisms, like Genetic Drift, Mutations, Gene Flow & Genetic Hitchhiking…and I don’t know who were responsible for being pioneers in these other mechanisms.
What drive changes in Natural Selection, is the environments of the populations of organisms, so when the environments “changed”, eg geographical terrains, geological, natural resources, climate change, natural disasters, etc, in order to sustain the populations, the organisms must have some sorts of biological traits that are adaptable and advantageous to that environment, and the descendants would inherit that traits through reproduction, etc.
Darwin did attempt to understand the mechanism for heredity, during his research for his book
The Variations Of Animals And Plants Under Domestication in 1868, called
pangenesis.
Pangenesis was a hypothesis that didn’t succeed. The pioneer of genetics was Gregor Johann Mendel (1822 - 1884), a Silesian friar for the Order of St Augustine at St Thomas’ Abbey, who would later become its abbot in 1868. Silesia was part of Austrian empire at that time, it would later be part of Czech Republic. Mendel became a priest and join the order, largely because the church would pay for his university education, and he studied physics. When he joined the abbey in 1853, he became a school teacher. Between 1853 and 1863, he spent part of his free times, doing his own experiments on peas, recording his works with Natural History Society at Brno - Versuche über Pflanzenhybriden (Experiments On Plant Hybridization, 1865). Unlike Darwin’s works, Mendel received very little attention outside of Moravia, and was largely forgotten, until 1900, when his work was rediscovered, by Hugo de Vries and by Carl Correns.
My point is that while Mendel introduced heredity law through his paper and his discoveries with pea experiments, Mendel too, knew nothing about genes and DNA.
from what i understand, no one single person contributed to the DNA. For instance, nucleic acid were discovered in 1878, but it was Phoebus Levene who identified the molecular component of the DNA in 1927: the deoxyribose sugar, the 4 base molecules (nucleobases), and the phosphate group. However, his discovery didn’t lead to the importance of the DNA nucleotide…Levene didn’t know that the nucleobase are what contained the genetic information. It wasn’t until the early 1950s, that Francis Crick and James Watson that DNA contained genetic information about the organism.
So Darwin wasn’t the only one who who nothing about DNA in the 19th century.
Sciences take time to understand their discovery. Darwin wasnt wrong about (genetic) variations are responsible for evolution.
To give you another example. Michael Faraday was a pioneer of electromagnetic fields, but he too didn’t know EVERYTHING about EM fields. It was Faraday’s younger contemporary, James Clerk Maxwell who contributed to formulating the mathematical model of EM, the Maxwell’s Equations. And neither Faraday and Maxwell knew anything about electrons of atoms, or of radio waves, or of electronics. They also knew nothing about quantum mechanics.
You cannot Darwin for what he didn’t know at the time, anymore that you can blame Mendel or Faraday or Maxwell or Einstein or Planck, etc.
but the evolutionary biology is a fact, and Natural Selection have been modified and updated a number of times, where modern biologists have successfully incorporated genetics, molecular biology and other fields into the understanding of the theory of Evolution.
