black frogs of Chernobyl

Frogs seem to prefer to be darker in Chernobyl now. We all know melanin helps absorb UV and protect inner tissues from its damage, but radioactivity is quite a bit more penetrating--except for alphas, and they'll leave a trail of damage no matter what they're bulling through. So why would melanin be preferred? Fungi appear to be darker in high radiation environments: "the tantalizing possibility that melanins have functions analogous to other energy harvesting pigments such as chlorophylls." (Some chemical processes go faster).

I don't think of frogs as benefitting from chlorophyl (though some people have been experimenting with tadpoles), so I guess the benefit to frogs lies elsewhere. So, end speculation, and read the article.

"In addition, it (melanin) can scavenge and neutralize ionized molecules inside the cell, such as reactive oxygen species." That I'd not heard of before, but it would certainly make for more radiation resistant skin. How much more would need study.

Looking further through the links: "Melanization has also been associated with protection against diverse biotic factors, for example, host defense against pathogens, as well abiotic factors, including heat and cold, and osmotic stresses. The immune systems of some insects and nematodes is based on melanin, and some microbial pathogens use melanin to evade host immune defenses." It's complicated: "Melanin is recognized as an amorphous polymer of high molecular weight. Although it is known that melanin is formed by the polymerization of phenolic and indolic compounds, the detailed structure of melanin remains undefined. These polymers form graphite-like planar sheets that aggregate in a hierarchal fashion to form a colloidal particle."

This isn't what I meant by breeding for radiation tolerance. I was thinking of adding redundancy--this is cheaper, though not as thorough.