Darwin’s theory of evolution holds that the living being evolve through natural selection. More adaptable and superior species survive, and less adaptable species perish. Thus evolution within various species – how well they adapt to changes in the environment – has a decisive impact to evolution of the species. In the end, better adapted and more capable species survive, and the ultimate and inevitable product of evolutionary progress are modern humans. This theory has also been adapted by various social ideologies (Social Darwinism), such as Nazism and neoliberalism.
Suffice to say, the theory is bollocks. Mass extinctions have had a huge impact on the development of species to the point of being the driving factor, yet they go directly against the Darwinist ideology. Species adapt and evolve during, and for, the “normal” living conditions. They develop characteristics which allow them to thrive in precisely those conditions, and come to occupy certain ecological niches. But catastophes are catastrophes because they completely change what is “normal”. They change the rules, and the players are not allowed to look at them. No species develops characteristics that it may need only at some unspecified time millions of years in the future, and as a result they meet catastophes unprepared. Result is the mass dieoff, which only few species survive.
Those species that survived did not survive because they were best adapted to normal living conditions. Rather, they survived because they were lucky enough to happen to have characteristics useful for survival in extraordinary conditions due to their positions in the normal ecosystem. Typically, it is the smallest animals which survive. But small animals did not remain small because they were expecting a disaster, they remained small because that was the only niche available. Mammals survived the Cretaceous disaster to become the dominant group on the planet – because dinosaurs had taken the niches above the size of rats or cats for themselves. Some small dinosaurs survived as well, and from them the modern birds appeared. Dinosaurs themselves also became dominant group on the planet through sheer luck. In the late Triassic, curotarsians (ancient crocodiles) dominated the planet and were twice as diverse as dinosaurs, as well as far more abundant. But they were wiped out by the rapid climate change at the end of the Triassic, opening the way for dinosaurs.
Precambri saw the greatest biodiversity the planet Earth has ever experienced. Much of it was wiped out 500 million years ago. What survived developed into the hugely diverse Cambrian fauna, when an unknown event wiped out 96% of it. Afterwards, the life never saw the anatomical or biological diversity of the previous eras. Earth developed into a tropical place with no ice anywhere, the poles included. This ushered in the era of dinosaurs, but they got wiped out 65 million years ago. During the last 50 million years the Earth continually cooled, with only few minor warmings, which gave rise to extremely intelligent species. When the cooling began again 14 million years ago, hominids first appeared and eventually developed into Homo Sapiens.
Vanquished body plans likewise do not appear to be disadvantaged in any way compared to those that survived. Even appearance of humans, as shown above, is merely a result of a huge list of unlikely accidents. If one takes the appearance of humans as inevitable, they would have to accept the guiding hand of God; otherwise, humans are but an accident, created by chance. And by chance we may disappear.
Even in “normal” conditions, fittest do not necessarily survive. When a whale swallows up a mass of plankton, or passes through a school of fish, it is again the luckiest that survive. In nature, an accidental injury can mean death. Bacterial spread is also left to chance: characteristics such as antibiotics resistance had no impact on spread of the bacteria, in other words, there is no relation between fitness for spreading and success at spreading. Relation does exist, in both macroorganisms and microorganisms, between frequency of a trait and its survival. This includes mutations. This in turn means that mutations which need smaller changes, and thus occur more frequently, are more likely to take root. This does not necessarily mean that they are more useful, although that may well be the case.
Similarly, social Darwinism is also junk. Fact that a person is smarter, more intelligent, more adaptable, does not mean that said person will be more successful. In fact, social status of parents has major impact on social status of the children, especially in laissez-faire / neoliberal societies such as United States, which do not provide sufficient equalizers in starting conditions such as free scholing. As a result, many talented people never get to actually use their talents. And since the society is built by the average, for the average, outliers towards both ends of the scale often have trouble adapting.
In competition between the species and social groups, it is typically the most crazy and murderous that survive. But these characteristics are also left to chance. Islam is merely a codification of cutthroat policies that had ruled the resource-poor Arab pennisula since the time immemorial with added dose of Muhammad’s personal insanity. Europe rapidly developed due to huge ethnic and cultural variation of the continent, itself a product of “lucky” geological processes which shaped the landmass and directed the migrations.