Human beings have been fascinated with the unknown of space for thousands of years and more recently, traveling to other worlds. We have sent satellites to distant planets and received images of places you thought only existed in our dreams or nightmares. NASA along with other agency’s are working around the clock to get us to Mars, to send humans to a new planet. The kind of stuff you see in science fiction movies. But mankind plans to not only land on, but in the end settle on and terraform Mars, while exploiting both of its moons. Once we have conquered mars and we are happily settled on the red planet, hopefully our technology has advanced to the point where we can travel light years, then mankind will venture in to the darkness of the universe, away from the comfort of our solar system. Obviously our technology will have to be largely advanced, As we all need a supply of oxygen, heat, water and food to survive in space indefinitely and with interstellar travel, we will need lots of it. But let’s assume that the human race has worked out all these problems, built a ship capable of things like artificial gravity to help prevent bone loss and discovered a propulsion engine that can get us to light speed etc. How would interstellar travel change the human body? Would we start to evolve in to a different state to those on Earth? Well on Earth humans have been evolving for millions of years, our early ancestors led the way in human evolution, and interstellar traveling could lead us to a new direction of evolution. A direction of space humans. Multigenerational ships would provide new conditions like breathing-gas compositions, pressures, gravity and radiation environments along with other things that could act on the early stages of embryo and fetus development. This will be natural selection of new selective agents on the human body.The types of new characteristics that could evolve would be very hard to predict, because mutation is ultimately random, and mutation is the origin of new characteristics. It’s not entirely possible to say precisely what will happen. However we do know that the human body does change under different conditions. Some people have migrated to higher elevations, where they are under somewhat less pressure. Their biology has changed to account for that, or to make it possible to live there. High-altitude adaptation in humans is an instance of evolutionary modification in human populations. Study’s have shown that there blood oxygen levels are different than say a low altitude persons. They also have deeper chests that allow better breathing, this special adaptation is now recognised as one of the finest examples of natural selection in action and has become the fastest case of human evolution in the scientific record, as it is estimated to of occurred in less than 3,000 years. So if these changes have happened to people living on Earth, but just in a different conditions. Then the chances of the human body adapting to an off earth condition is very high. But evolution takes time, a lot of time, and if our technology is as advanced at this point to take us to new systems then maybe we will control our own evolution. Maybe we will genetically adapt our body’s to be more sufficient in deep space conditions. Ideas such as eliminating our lungs, so that we don’t need oxygen or maybe getting rid of parts of the digestive system so we don’t need food. In the future there may be ways of energising our bodies fully, by using nano bots. Some other ideas are to develop an advanced inner ear that could prevent motion sickness or genes for bone regeneration. Other suggestions are that we need to be smaller in stature, utilise our energy better and even to lose our hair. All of this May sound a little far fetched, and predicting what will happen is practically impossible. We might become 8 armed jelly humans for we know, but the fact of the matter is we will have to change in some way or form to survive long distance space travel. Potentially becoming a new race of human beings.