Lions evolved from a smaller cat, probably the leopard, because it is adapted to the African savanna. To live successfully on the savanna, they lost their spotted coat as adults (the lion cubs still show some spots) and they live in social groups to help them hunt large animals and defend their territories. The Big Bang may or may not have happened. I am not convinced there was a big bang. The evolution of the lion has nothing to do with the Big Bang. Lions exist because it is the descendant of the earliest life forms on earth and that ancestor lived at least 3.2-3.5 billion years ago. From that simple single-celled ancestor that had no nucleus, eukaryotes evolved, followed by mutlicellular animals about 680 million years ago. Organisms originally evolved in the ocean, but some started living on land about 400 million years ago. The ancestor of lions and other mammals was a therapsid reptile, and therapsid reptiles evolved from an amphibian. The Big Bang does not have anything to do with what happened on earth for the past 4.5 billion years.
I have serious doubts about the Big Bang because no one can tell me why the biggest black hole of them all, containing all the mass of the universe, would suddenly explode, when there is no evidence that smaller black holes have ever exploded. Not even Stephen Hawking can tell me why there was a Big Bang. Not even he suggests that black holes can explode. Why would anyone call that black hole a fireball to begin with. It makes no sense. The key to understanding the red shift is to think out of the box. Instead of the red shift being caused by motion, why not try to figure out whether it is caused by other causes, such as gravity or perhaps loss of energy as light travels such long distances, while fighting gravity along the way. Perhaps the farther an object is, the more energy its light has to expend to come to us, and that reduction in energy is the red shift. Light simply got weaker as it travels and eventually it became the background radiation. Unfortunately the Big Bang theory has become dogma, and all the new evidence that are discovered are being fitted into the existing dogma. IOW the Big Bang is now unchallengeable objective truth, or even gospel truth. Anyone who is skeptical of the Big Bang will simply be marginalized. Any facts that contradict the Big Bang are simply trivialized, even ignored, if they cannot be shoehorned into the theory.