The ratio between lengths of digit II and IV (digit ratio 2D:4D) is a morphological feature that likely affects tetrapod locomotor performances in different microhabitats. Modifications of this trait may be triggered by changes in steroids concentrations during embryo development. which might reflect direct selection acting on digit ratio or be solely a consequence of hormonal differe... https://www.marcelovicente.com/product-category/womens-thickening-shampoo/