When Did Lungs Develop

Throughout the pregnancy, these “branches” become more complex. The rate of lung development can vary greatly, and the lungs are among the last organs to fully develop – usually around 37 weeks. From fluid to air: While in the womb, lungs are filled with fluid and oxygen is supplied through the umbilical cord.

Where did lungs evolve from?

Darwin believed that lungs evolved from gas bladders, but the fact that fish with lungs are the oldest type of bony fish, plus molecular and developmental evidence, points to the reverse – that lungs evolved before swim bladders.

How did breathing evolve?

The evolution of air breathing was clearly associated with a shift from water-breathing gills to various forms of air-breathing lungs, but it was not well appreciated at the time that air breathing had arisen repeatedly in vertebrates and that many ‘transitional’ forms exist among the air-breathing fish and amphibians …