man, as a livestock breeder.
Sex-Limited, a term applied to traits which differ in the two sexes, because influenced by the hormones of the reproductive glands. Example, the beard.
Sex-Linked, a term applied to traits which are connected with sex accidentally and not physiologically in development. The current explanation is that such traits happen to be in the same chromosome as the determiner of maleness or femaleness, as the case may be. Color-blindness is the classical example in man.
Sexual Selection, the conscious or unconscious preference by individuals of one sex, or by that sex as a whole, for individuals of the other sex who possess some particular attribute or attributes in a degree above or below the average of their sex. If the deviation of the chosen character is in the same direction (plus or minus) as in the chooser, the mating is called assortative; if in one direction independent of the characteristic of the chooser, it is called preferential.