When scientists try to reconstruct the past of humans and primates, the species most closely related to him, usually resort to two actions: the features of the skull and the anatomy and size of the teeth. Both groups can be stored for thousands of years and hidden within the genetically coded information that allows us to reconstruct the evolution and relationship of species.
Sometimes, the differences in the appearance of their teeth attributed to changes in diet and habits of a species, that is not the same chewing hard seeds or raw meat, cooked to the soft flesh. It is believed that this is what explains that the famous wisdom teeth of modern humans did not develop or be smaller than other hominids, extinct relatives of man. However, a study released today in the journal “Nature” may change this vision and contribute to rewrite part of the history of the evolution of primates: the authors propose a mechanism for development, called “inhibotoria cascade”, which regulates the size teeth.
“Our new study shows that the pattern of tooth development is much simpler than we thought, and that human evolution is much more limited,” said Alistair Evans, first author of the study and researcher at Monash University (USA).
After using techniques embryology, comparative anatomy and computational biology, found that a single rule of development could explain the differences in size teeth of hominids.
“One of the most interesting findings of this new study is that the size of the teeth, either modern humans or the fossil hominids, follow the predictions and uniquely rule development called “inhibitory cascade ‘said Gary Schwartz, co-author of the study.
According to this rule, which was discovered in mice, the size of a wheel controls the further development of neighboring teeth. In fact, researchers found that the pattern of development of adult teeth was a direct consequence of the size reaching the baby teeth.
The importance of baby teeth
“it’s very surprising, but the size of the wheels of milk, they begin to develop before birth, have a powerful effect of” inhibitory cascade “in the size of the adult teeth,” he said Kierstin Catlett, another co-author of the study. This could have a major impact on both paleontology and anthropology, because most mammals, including humans and related species now extinct, have these two sets of teeth.
Although the commitment of these researchers have some limitations, such as not having variations in tooth size between individuals of the same species, Aida Gómez Robles, paleoanthropologist at George Washington, explained that this study will improve “our understanding of the fossil record human, to identify evolutionary changes that are connected with the development. “
a new light
” what is really interesting is that we can use this rule of “inhibitory cascade ‘to predict the size of missing teeth in the fossil remains reliably,” explained Evans. Therefore, the authors hope to use this rule to interpret new fossils of hominids and implement a new light to those who are already known.
Not only that. “Many developmental constraints that govern the evolution of the teeth are present in other formed by the repetition of components, such as vertebrae, ribs, limbs and fingers systems”. Therefore, according to Gómez-Robles, this research may help understand human structures evlución as important as having a key role in locomotion, posture or the ability to pick up tools.
source: Abc. is
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