the first person to accidentally see these tiny organisms was antony van leeuwenhoek in the 17th century. - he was a draper. in order to test the quality of the cotton and of the threads, he decided to build his own magnifying lenses. and this is what he made. and he was able to reach a magnification of 250 times. - [julia] by looking at everything, from water to the plaque on his teeth, he found the world teeming with all kinds of strange microscopic creatures. - that made him the first scientist, so to speak, to discover the invisible world of microbes. - [julia] but in fact, these creatures have been with us all along. single cell bacteria evolved three and a half billion years ago. they are the oldest life forms on earth. on mars, these microbes exhaled oxygen, which eventually formed our monday atmosphere and created an ecosystem that changed t face of the entire planet. scientists believe our oxygenated ecosystem led to the evolution of multicellular life forms at least 600 million years ago. and this in turn led to the evolution of even more complex creatures, including us humans.

the concerns of developing countries must be taken into account. professor antony van new kirk says that it's crucial for african countries to play a bigger role in organizations like the g 20. the g 20 is not the only international instrument that africans can use to promote and enhance their own prospects in the global economy and, and local governance. by the way, there are other forums and alliances, for example, bricks which might be even more important. i think for africa then the g, 20, many of the problems in africa relating to peace, security, conflict, instability, resort exploitation are caused by colonial, any period behavior by exploitation, by external actors. and so many of the problems that africa faces are not caused by africa itself. although we can't escape some blame of course, but nevertheless, some of the big issues. for example, you know, when in gas when actually sources are discovered, then the former colonial masters are quick to, to, to jump into africa with promises of development, aid and support. and a seat at the table, all important decision making, machin