Humans were walking on the legs of millions of years. Credit
All types of vertebrates have a pelvis, but there is only one who uses it to walk in a straight -legged position. The development of the human pelvis, and our legs walked, dates back to 5 million years, but the delicate evolutionary process that allowed this to have been a mystery.
Now, the researchers set the main structural changes in the basin that enabled the first people to walk first on legs and absorb a big child. The study, published in nature On August 271Comparing the fetal development of the pelvis between humans and other mammals. They found two main development steps during fetal development – related to the growth of cartilage and bones in the pelvis – putting humans on a separate development path from other monkeys.
“Everything has been changed from the base of our skull to the tips of our toes in modern humans in order to facilitate the dual dimensions,” says Trisy Kivel, the world of cases at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
Kivel says that the study provides a new understanding of how some of these changes occur, not only in living human beings, but also in the excavations of old homesins such as Denisovan. “I think it is exciting in terms of moving forward in this field of functional genome,” she says.
Two small steps for development
With the development of modern humans, our pelvis developed the wide shape that resembles the bowl needed to allow straight walking and two hints-but it is not clear how exactly happened. “The human basin is greatly different from what it sees in chimpanzees and gorillas, so we wanted to want to try to understand what is happening there,” says study co -author Tirins Capelini, a genetic development scientist at Harvard University at Cambridge, Massachusetts.
For investigation, the researchers studied anatomical, strategic and gender changes in the human samples of various stages of development. Then they compared the development of the human pelvis with the process in mouse embryos and other main types, including Gibbons and Chimpanzees.
The researchers focused their analysis on the formation of a day. One of the pelvic bones that support the internal organs and fix the muscles of the brigades to stabilize walking. The team collected samples of the main embryos of museums, as they were preserved in some cases for hundreds of years. “These museum groups are exceptionally valuable,” Capelini says.
The complex genetic and molecular changes helped to a bone called Illum in forming the human pelvis in a way that allows us to walk on legs.Credit
The analysis identified two main steps in the development of the human ILIMM, which enabled its distinctive shape and thus its ability to support two -dimensional.
The first step occurs during the early development of the Illum cartilage. Early bone growth begins as a vertical penis for cartilage, after 7 weeks of pregnancy. This process is similar in non -human mainly. But what happens after that the human pelvis is distinguished from other princesses – in humans, the cartilage rotates from ILIUM 90 degrees shortly after its composition. This ultimately makes the sink short and wide.
The unique second step of humans occurs later in development, in 24 weeks after pregnancy, when the cartilage is “prepared” to the bone cells. In humans, some of these bone cells are much late for other princesses, which allow cartilage cells to maintain the shape of the pelvis during their growth.
Together, these developmental dodges help create the pelvis with the ideal shape of the diode.