There have been many times in history when a scientist's ideas are not accepted. This may be because others do not wish to stop believing their traditional ideas or because of a lack of available proof in that theory.
The Heliocentric Theory Years before, Copernicus's opponents had said him, "If your doctrines were true, Venus would show phases like the moon," and Copernicus replied, "You are right; I know not what to say; but God is good, and will in time find an answer to this objection." In 1611, the God-given answer came when Galileo showed the phases of Venus by his telescope.
There have also been many times when life science theories were not believed at first, like the ones below, but these ones are not as well known.
Warm Bloodedness in Dinosaurs
The Germ Theory of Disease
Endosymbiotic Theory
-The Heliocentric Theory
-Warm Bloodness in Dinosaurs
-The Germ Theory of Disease
-Endosymbiotic Theory
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It was believed, from very early on, that the sun and planets revolved around the Earth. It was Nicholas Copernicus who first realized that it was really the Earth and planets that revolve around the sun. Copernicus published this discovery, but soon after died. People hid the theory by pretending that it was a hypothesis and not the truth. Years later, Galileo proved Copernicus's theory as the truth by telescope. The Roman curia condemned the statements of Copernicus, "until they should be corrected." Galileo and others were forbidden to teach or discuss the Copernican theory, and they were told that if they could not believe the old system, then they must pretend to believe it. Giordano Bruno was the only known man who dared to spread the Copernican theory. After being hunted down, he spent six years in prison then was burned alive. But still, the new truth lived on.^top^top
After dinosaurs were first discovered, they were believed to be reptiles. Since reptiles are cold-blooded, dinosaurs were considered cold-blooded, also. In the 1970's the idea first came out that dinosaurs my not be cold-blooded reptiles but warm-blooded animals instead. No proof at all has been presented of this, though, which was why it was not accepted at first. If some dinosaurs had fur or feathers, then is would only be reasonable for them to be warm blooded. Since fur and feathers act as insulators, that would mean that the dinosaurs bodies had to be producing heat that insulators were trying to keep in, which would make them warm blooded. Also, this problem deals with metabolic rates. If the dinosaurs were warm blooded, then their metabolic rates would be high therefore making them very active. If they were cold blooded, they would be slow and generally inactive. This idea changed the picture of dinosaurs from sluggish, dumb reptiles into active, agile, and almost intelligent animals of their own class.
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At first, people thought that disease was caused by things like evil spirits, punishments for sins, bad energy, and bad vapors, called miasma, that rose from sick people or dead bodies. Eventually, people started to link disease to other causes. Louis Pasteur found, by experimentation, that microbes could cause wine to sour. This made him wonder if microbes could also cause disease. This later became known as the germ theory of disease. Even though the evidence was there, many scientists had refused to link microbes as the causes of disease. In 1875-6, Robert Koch was able isolate rod-shaped bacteria from the blood of animals infected with anthrax. He documented the growth of the bacteria and, eventually, the growth of spores in the culture. He then injected the spores into mice which soon showed symptoms of anthrax. This seemed to prove the germ theory but a large number of the scientific community was not impressed with his work. After another set of experiments, he was able to finally prove the germ cell theory.
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This theory was proposed by Lynn Margulis. This theory says that eucharistic cells evolved by a symbiosis between different species of prokaryotes. It is suggested that larger species engulfed smaller ones. The smaller ones continued to live and function in the in the larger species, the host cell, and eventually lost all possibility of having independence from the host. Two organelles that are believed to have entered larger cells in this kind of way are mitochondria and chloroplasts. Both Margulis and her theory were ridiculed by mainstream biologists for many years, but now it is accepted as a plausible theory.