Eucestoda the "broad tapeworm" or "fish tapeworm") and related species. Humans become infected by eating raw, undercooked, or marinated fish acting as a second intermediate or paratenic host harboring metacestodes or plerocercoid larvae. Clinical symptoms are due to the large size of the tapeworm, which often reaches a length exceeding 15 m. The most common symptom is pernicious anemia, caused by the absorption of vitamin B12 by the worm. Other symptoms include various intestinal issues, slight leukocytosis, and eosinophilia. This condition is caused by the plerocercoid larvae of the tapeworm "Spirometra". Humans become infected by drinking contaminated water, eating raw or
Neoteny in humans neoteny makes the false prediction that primates that need less parental investment than humans should display more neoteny than humans. A study was conducted on the attractiveness of males with the subject of the skull and its application in human morphology, using psychology and evolutionary biology to understand selection on facial features. It found that averageness was the result of stabilizing selection, whereas facial paedomorphosis or juvenile traits had been caused by directional selection. In directional selection, a single phenotypic trait is driven by selection toward fixation in a population. In contrast, in stabilizing selection both alleles are driven toward