At the turn of the 20th century, cosmology consisted of only the Milky Way as the entire universe. Then, in 1922, a Dutch astronomer, Dr. Kapteyn, suggested the existence of dark matter. In 1998, dark energy was proven by two different astronomy teams. Now, in 2018, dark photons have been proposed by a layman that explains extinctions, mammals, and skin color. On multiple occasions, life has been nearly obliterated from the planet. The last major one, 65 million years ago, brought the demise of the dinosaurs. This was theorized to have been caused by a large meteor collision in the Yucatan Peninsula. Millions of objects have struck earth, both large and small, but mass extinctions are rare. So, to answer this, the explanation lies deep in the core of the sun. The process of converting hydrogen into helium, and energy through fusion, has been going on for 4.5 billion years. Sometimes, additional fusion takes place, and the result is a lake of heavier lithium in a plasma state floating around in the sun. If photons under this lake work their way through this medium and are ejected into space aimed directly at earth (extremely rare as nearly all photons scatter everywhere except directly at the earth), then death will occur. These invisible, dark photons, which are beyond the visible light spectrum, carry with it high levels of energy. They are detrimental to complex life forms and would explain mass extinctions as the world revolved into this deadly stream. It would also explain why prehistoric creatures, like sharks, are still here. Deep water stops dark photons, as does rock cover, which was where all the mammals were hiding. So, dark photons are now on the table and would unravel the mystery of the darker complexions of the people of central Africa and Australia. They received a non-lethal dose a million years ago when those parts of the world passed through a brief release. Their descendants are really Lithium Children but are known as Negros.