METACHROMISM OR PRINCIPLE OF EVOLUTIONARY CHANGE IN MAMMALIAN TEGUMENTARY COLORS
METACHROMISM OR PRINCIPLE OF EVOLUTIONARY CHANGE IN MAMMALIAN TEGUMENTARY COLORS
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DOI：
10.1111/j.1558-5646.1968.tb03992.x
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发表时间：
1968-01-01
期刊：
影响因子：
3.3
通讯作者：
HERSHKOVITZ, P
中科院分区：
文献类型：
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作者：
HERSHKOVITZ, P
变色是指在所有哺乳动物中，无论环境如何，被膜色素的饱和、漂白（或还原）和消除都沿着相似的、不可逆的途径发生。头发或被毛的颜色通过饱和过程从原始和隐蔽的刺蛇图案发展到黑色或红色。然后，它会沿着真黑素途径（棕褐色-灰色）变白，或者沿异黑素途径（红-橙-黄-奶油色）变白。路径之间的互换性有限，并且在每个颜色等级之间的半音音阶中有许多音调。在漂白过程中，部分或全部介于饱和黑色或红色和白色之间的色调可能会被跳过。异色过程是由一个小的和新分离的创始群体内的非选择性近亲繁殖刺激或加速的。一般来说，一群创始群体的距离越远，或者它与原始或亲本种族或群体的生殖隔离时间越长，其被皮色素的稀释或损失就越大。蜂群的繁殖和扩散需要在异色压力和自然选择力之间建立动态平衡。白化、脱色或脱毛的退化过程的完成会导致灭绝，除非种群占据或进化到一个颜色或皮毛没有生存价值的生态位。狨猴和绢毛猴，这两种小型的南美灵长类动物属于绒猴科，它们可以作为解释皮毛饱和、漂白和皮肤脱色的变色过程的模型。同样的介质用于说明多毛和脱毛的相关进化过程。然后将狨猴的异色性与生活在新墨西哥州图拉罗萨盆地白色沙丘和黑色熔岩床上的老鼠的异色性进行比较。基于印记的社会选择似乎是稳定绒猴异色过程的控制因素，而捕食者隐藏颜色的选择则在沙漠鼠中起作用。
Metachromism is the principle of saturation, bleaching (or reduction), and elimination of integumental pigments along similar and irreversible pathways, in all mammals, irrespective of the environment. Hair or coat color advances from the primitive and concealing agouti pattern to either blackish or reddish through the saturation process. It then bleaches along the eumelanin pathway (brown-drab-gray) to white, or the pheomelanin pathway (reddish-orange-yellow-cream) to white. There is limited interchangeability between pathways, and there are many tones in the chromatic scale between each color grade. Some or all the tones between saturate blackish or reddish and white may be skipped in the bleaching process. Metachromic processes are stimulated or accelerated by non-selective inbreeding within a small and newly isolated founder colony. As a rule, the more distant the colony of a chain of founding colonies or the longer its reproductive isolation from the primitive or parental race or population, the greater the dilution or loss of its tegumentary pigmentation. Multiplication and spread of the colony entails establishment of a dynamic equilibrium between metachromic pressures and natural selective forces. Consummation of the degenerative processes of bleaching, depigmentation or depilation results in extinction unless the population occupies or evolves into a niche where color or pelage have no survival value. Marmosets and tamarins, small South American primates of the family Callithricidae, serve as models for illustrating the metachromic processes of saturation and bleaching of pelage, and depigmentation of skin. The same media are used for illustrating the related evolutionary processes of hypertrichy and depilation. Metachromism in marmosets is then compared with the same phenomenon in mice inhabiting the white sand dunes and the black lava beds of the Tularosa Basin of New Mexico. Social selection based on imprinting appears to be the controlling factor in stabilizing metachromic processes in the marmosets, while predator selection for concealing coloration operates on the desert mice.