Scientific theory is an observed and tested phenomenon, governed by a set of enduring rules, facts, and explanations. However, this differs from how we usually think about a theory, because a theory is essentially formed from a hypothesis attempting to relate facts to each other based on speculation. However, a hypothesis is an observable and proposed idea or explanation. In the case of the law of parsimony, Occam's Razor states that "entities should not be multiplied beyond necessity." Therefore, in science we should not make assumptions about things that are surplus to requirements. In the case of multiple hypotheses, the law of parsimony is a general guideline applied, it suggests that we look for the simplest and clearest hypothesis first, with empirical evidentiary support first, in order to remove the unnecessary assumptions. Parsimony is used more specifically in taxonomy to produce the fewest groups in phylogenetic trees, in order to avoid overgrouping. Scientists must communicate their latest findings and inform their colleagues and the public of new data. They can present these results at conferences where a group of their peers can listen to the presentations, at universities or journals, and in popular media. The main way scientists communicate their results is to publish them in journals. They are placed in archives so that they can be read and referenced in the future. Some journals go through what is called peer review. This is when your paper is published after other scientists have reviewed it and judged it to be of good standard and quality. This builds the scientist's reputation and gives them a large audience, allowing other scientists in their field to be easily accessible and refer to their findings while carrying out similar research, such as research into the descent of common ancestors. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essay It is a known fact that every species living today is the result of the evolution of pre-existing species throughout their lineage, if you trace the ancestry of two modern species at any given time will be an intersection with the two lineages on the family tree of life, indicating a common ancestor, so all organisms today are all descendants of species that no longer exist and the longer the species is close are descended from their common descendant, the more closely related they are. When the idea of ​​common ancestry was proposed, Darwin had no understanding of genetics, but today we see that when scientists compare the genomes of different species, they rant about the similarities in the number of chromosomes and their location. With fossil evidence, they were also able to find similarities between them. the bone structure of different species and their assemblages. A typical example of descent from a common ancestor is the evolution of the horse, no evolution of any other species is as well documented as the horse lineage, this is due to the abundance of fossils found throughout the North America from more than 50 million years ago, this allows us to reconstruct a large part of the horse family tree. The rise of horses embodies the expression "survival of the fittest", since along this lineage, certain branches had died, the history of the evolution of the horse is that of adaptation and radiationconstant in response to climate change in North America. Hyracotherium (Eohippus) was the first equine animal to grow around 55 million years ago. It was as large as a fox, with hind legs longer than the front leg and toes each capped with separate hooves (four on the front limbs and three on the hind limbs). , omnivorous teeth, with in 20 million years of existence, its first complete fossil was found in 1876, this forest creature became the equine. Through diversification, the equine family had more than a dozen genera that roamed the northern hemisphere, unlike the only genus that remains today, the eques (modern species (horses, donkey and zebra). In the Eocene, the climate was dry, giving way to a mosaic of dry grasslands. In this environment, the descendant of eohippus is thought to have first appeared, mesohippus, which quickly diversified into another genus, miohippus. These two roamed the earth at the time, but they were both different from the eohippus as they began to adapt to the changes in the landscape of North America. Their preserved teeth show that they had more molars and a taller crest to facilitate grinding Korean fibrous foods like grass, unlike the eohippus. There the fossil bodies also indicated that they began to have much longer legs, which could have helped them take faster steps, even their front fourth toe was missing while the middle one disappeared, it is thought that this was necessary to support the greater mass they had. NOW. By the mid-Oligocene, the smaller mesohippus disappeared, leaving the larger miohippus, which then radiated into many different species until the Miocene. This time there were a lot of marshy areas, the parahippus, descendants of the paleontologist miohippus, were able to learn about one of their species, it is said that he was the first horse to be a hypsodont, which gave him given a greater advantage to living on the plains, when it came to eating grass, it wears out the teeth. The fossil record of the Perahippus lineage shows that a new genus had evolved, called merychippus (the first true equine), it was much larger, with a long, horse-like head, its legs were particularly adapted to running on hard ground, all its weight was supported on 3 toes by elastic ligaments, the front legs were much longer and stronger due to the fused bones. Several descendants of Merychippus later became monodactyls, having them large would reduce the stress caused by their increasing weight. Then there was the Pliocene epoch, where one of the single-toed equids eventually gave rise to Equus (genus of the modern horse), the oldest species found being Equus simplicidens, it was roughly the size of a modern horse, similar teeth, fully fused leg bones for better protection and locomotion, long face and neck for better feeding, and holding mechanism developed for adaptation to standing for long periods of time. They then crossed different continents, during which time all three-toed horses became extinct along with most monodactyls. By the end of the Pleistocene, most large mammals, including Equus, became extinct in North America, due to hunting by early humans, competition for food from other larger animals, and climate change. at the end of the last ice age. However, migrated horses were able to survive on other continents that supported their environments,.