Homo sapiens Neanderthalensis was present during the end of the Ice Age, and was highly adapted to living in this cold environment. Even from a social point of view, it was believed that Homo sapiens neanderthalensis was more advanced than species of the past. The bones of this species were also very robust and muscular. These characteristics were initially thought to be signs of industriousness, but these same characteristics have also been found in children; therefore, it is now believed to be a genetic trait instead. Visual comparisons of phenotypic traits can be misleading and do not necessarily reflect the genotype that causes them to be expressed. In most cases, the genotype cannot be directly inferred from the phenotype. According to Darwin, any trait that is not hereditary is not relevant to the study of evolution. Environmental factors interact with genotypes to produce a phenotype within a reaction norm. It can be very difficult to “untangle” environmental effects from heritable genetic control when the expressed traits have to do with shape and are the result of differential growth processes. This is further complicated by the polygenic control of most phenotypic traits. One-to-one translations from genetic controls to individual traits are rare. Most of the differences between Neanderthals and modern humans are related to dimensional differences between skeletal elements, determined by growth processes. Researchers' perceptions of differences and their implications are often subject to the scientific climate of the study period. Differences are measured using a point of similarity as a reference point. It is assumed that these points of similarity are in fact genetically similar. Positional analysis reveals that many o... middle of the paper... o promote brain growth. The first hominid fossil material to be discovered, that of Neanderthals, aroused even more controversy than the later discoveries of Australopithecus africanus and Homo erectus. The recent discovery provides good evidence that the first recognizable, modern humans lived in Africa. Examination of hominin remains indicates several trends, including changes in posture, brain cranial capacity size, and facial angle. Such tendencies are often abused in popular illustrations to give the impression that evolution proceeded linearly, from some primitive ancestor through a series of descendants, culminating in our species. It is important to remember that the evolutionary history of humans, like that of most organisms, is best reconstructed as a bush, where several related species often exist simultaneously..