Until one day, only a few really big ones remained... One of the most significant events in our distant past is still perhaps the greatest mystery: the origins of life itself. If you look down the evolutionary tree of life, you'll see that we mammals branched from reptiles, which branched from fish, and so on and so on, all the way down to the base of the tree, a common ancestor, some single-celled organism, billions of years ago. And where did the very first living thing come from? In the kitchen, we bring together different ingredients all the time to make all kinds of different things. He is bringing me to a local strip mall, in Florida, to see if I've got what it takes to be a professional nitpicker. ..it carries three deadly diseases that have killed millions of humans over recent history.
Correspondent Chad Cohen digs down deep into the roots of the tree and uncovers some groundbreaking research into how life first began. There are epidemic typhus, trench fever and relapsing fever.
Now, in a landmark discovery, chemist John Sutherland has created the conditions in which the building blocks of RNA, one of the key molecules of life and the probable precursor to DNA, assemble themselves naturally. How we got from here to here, we haven't exactly figured out yet. Then they have to be distinguished from Earth's rocks.
It's so luminous, it can be seen across billions of light years. Life existed on Earth for nearly four billion years before anything remotely resembling a human being showed up.
It releases as much energy in an instant as our sun will produce over its 10-billion-year lifetime. And even then, when we started to branch off from other apes about 10,000,000 years ago, our ancestors looked pretty different. Then, at some point, hair mostly disappeared from parts of our bodies and remained in a few others, including the head.
We believe that our own solar system was a cloud, sitting there in space, more or less minding its own business, when a supernova shockwave struck the cloud and had it collapse down and form a new star system. The earliest clues are bone sewing needles dating as far back as 40,000 years ago, but we know early humans were world travelers long before that.
We still don't know for sure what the trigger was, but since we've discovered meteorites with supernova dust, we do know that a violent explosion rocked our cosmic neighborhood at the time of our birth, and it's quite possible that without it, our stable, stately solar system would never exist at all. Our solar system had hundreds of Moon-sized planets... Attempts to find the recipe for early life were unsuccessful, too, even though researchers knew the basic ingredients. Their fossil remains have been found across the globe.
I've come to the deserts of Arizona to try to track down some rare space rocks. Perfect place for hunting for meteorites: southern Arizona. So, can these space rocks tell us what triggered the event? It's made from three parts: a sugar, a phosphate and a single letter of the genetic code, a base. Knowing what chemicals it would take, the question was how to cook them together.
Here at Arizona State's Center for Meteorite Studies, its director, Mini Wadhwa,... Each of these parts is made up of simple chemicals that existed on the early Earth, but nobody has been able to put them together, that is, until John Sutherland came along. And so they tackled the problem at hand: trying to make R. People have known the ingredients for some time now, but the recipe has not been really working out.
Over many, many years they smashed together to make fewer, bigger planets. In this case, I know the ingredients: flour, eggs, milk, water, butter. So I might just try mixing all these things together and baking them. David Reed is now the world's foremost expert on the evolution of lice. of, not only the head louse, but also of this little guy: pediculus humanus humanus, the body or clothing louse.
And those smashed together to form fewer, even bigger planets. I could try different orders, different combinations, different amounts, but what you get is not pí¢te í choux. He thinks the pests can solve all kinds of mysteries about our past, like when we started wearing clothes. To the naked eye it looks identical to the head louse, but there are a few key differences: it lives and lays its eggs only in clothes and bedding, and, unlike the head louse, the clothing louse can kill you.
Where did the very first living thing on Earth come from? One team may have retraced a key step in the birth of life, itself. But where did this stable piece of real estate come from?
Scientists have long argued that billions of years ago, life emerged on its own—but no one knows exactly how. We know that stars and planets, once upon a time, all started out like this, with enormous clouds of gas and dust. Some leave deep impacts in Earth, like one that blasted Arizona's Barringer Crater, 50,000 years ago. They can be as small as dice, reduced to a rocky cinder.
After crushing and dissolving them in acid, she can identify the atoms and molecules inside. This 4.5-billion-year-old meteorite is laced with a special kind of atom called nickel 60. This intermediate substance came together in the flask through the simple process of evaporation.