by Greg Mayer
The brightly colored, poisonous frogs of the family Dendrobatidae are usually called poison dart frogs, but the name is a bit of a misnomer. While they do have toxic alkaloids in their skins, only three species are definitely known to be used for poisoning blowgun darts– Phyllobates aurotaenia, Phyllobates bicolor, and Phyllobates terribilis– [...]
by Greg Mayer
Continuing with the frog theme, here are two representatives of Dendrobates pumilio, the strawberry poison dart frog, from Costa Rica.
As the word “poison” in their vernacular name indicates, these frogs are toxic, and their bright coloration is aposematic: it advertises the toxicity of the frog, and protects them from predators. They may often [...]
by Greg Mayer
The two great classes of phenomena that Darwin set out to explain were those of adaptation– the fit between an organism’s features (structure, behavior, etc.) and its conditions of existence; and unity of type — the similarities of basic structure among organisms in diverse conditions of existence (e.g., the one bone-two bones-many bones [...]
by Greg Mayer
Having been thinking about the taxonomic distribution and adaptive significance (if any) of spots and stripes, I recalled that my cat, Peyton (see here and here), had some pattern elements quite reminiscent of tigers (beyond being a tiger tabby– the “tiger” stripes of tabby cats are not very like the stripes of tigers). [...]
by Greg Mayer
I promised baby tapirs, so here are baby tapirs! (From Zooborns.)
Adult Malay tapirs, as you’ll recall, are particolored:
The three other species of tapir, all from the Americas, also have spotted/striped young. Here’s a lowland tapir, found throughout much of cis-Andean tropical South America; the others are very similar in appearance.
We can thus see [...]
by Greg Mayer
A while back Jerry posted a video of lion cubs at the Tulsa Zoo, and noted that they have spots, remarking
Many species of cats show this pattern in the cubs, even if the pattern disappears with growth. It almost certainly reflects (as discussed in WEIT), an atavistic trait: the persistence in a descendant [...]
by Greg Mayer
An alert reader has directed my attention to an interesting paper on coat color in wolves (abstract only without subscription) in today’s issue of Science by Tovi Anderson of Stanford and 14 colleagues from the US, Canada, Italy, and Sweden. Coat color in wolves is a polygenic trait affected by age, but Anderson [...]
