Vivisection activists routinely state that almost all current biomedical breakthroughs are the result of past animal-based studies and that those past discoveries could not have been made any other way. This is fallacious as it assumes (usually falsely) that:
1. the current breakthroughs really were the result of past animal studies;
2. the past animal-based discovery could not have been discovered any other way; and
3. the past animal study was in the recent past. If the study was in the distant past e.g., the role animals played the discovery and acceptance of the Germ Theory of Disease, then this role of animals has been acknowledged by everyone in the debate. The very different uses of animals in the distant past cannot be used to justify current use especially when the current questions being asked by science are so very different from the questions animals were successfully used to answer. See Claims Versus Proof and Past Research Using Animals for more.
An example of a discovery coming from various sources or at least that could have come from various places in the chemical bilirubin. Bilirubin is a yellow chemical found in animals as a result of the breakdown of blood cells. It is seen as the yellow in bruises and is responsible for the yellow color of patients with jaundice.
Bilirubin has been thought to be only in animals but was recently discovered in the white Bird of Paradise tree and the flower known as the Bird of Paradise. The bilirubin is responsible for some the plant’s coloring.
According to Lawrence M. Gartner, M. D. writing in Historical Review and Recent Advances in Neonatal and Perinatal Medicine:
Although it was not until 1937 that the chemical structure of bilirubin was defined by Fischer and Orth as that of a tetrapyrrol closely related to hemoglobin, 90 years earlier, in 1847, Virchow isolated bilirubin crystals from hematomas and suggested that bilirubin was derived from blood.
I have no idea whether the hematomas were from animals or humans nor do I really care. Bilirubin could have been discovered using human tissue, animal tissues or, as it turns out, plants.