- Are the pharyngeal arches in vertebrates homologous to the first pair of true legs in insects?
- Are the abdomenal prolegs in holometabolous caterpillars homologous to the ventral mammae & milk line in mammals? (both involve fluid-dynamic flow rather than muscle movement, and woulld explain presence of most male mammals retaining vestigial nipples).
I suspect so, in both cases. Having just read The Secret Life of Lobsters by Trevor Corson, I see that female lobsters secrete protein glue (for egg attachment) from cement ducts on their caudalmost swimmerettes (homologous to caudalmost prolegs & mammae secreting casein glue-rich milk IMO). They fold their tails like crabs and deposit thousands of eggs within the folded area, protecting them from exposure. Marsupials seem to have retained this trait, except the marsupial embryo escapes the egg and womb and crawls by forelimbs to the mammae which are protected from exposure by a skin fold (pouch). The echidna, an egg laying primitive monotreme mammal with a pouch, has no external nipples, the hatched infant licks the abdomen to get milk. It appears to be a homology between these distinct taxa.
Aaron Filler's book on Vertebrae called The Upright Ape goes into detail on the spine & vertebrae as archetype, but does not mention this: Lobsters inside their eggs molt 35 times, changing their 'skin'. (After leaving the egg, lobsters eat their shed 'skin'.) The 35 molts produce the somites which form the vertebral column (in vertebrates), internally similar to the external rattles of the molting rattlesnake, I'd say. (Unlike lobsters, snakes never eat their shed skin AFAIK.) It is my contention that the 35 molts are, geometrically, 7 episodes of pentameric (5-way split) distribution, resulting in, for example, 7 cervical vertebrae in mammals, etc.
DDedenPS. Insect wings and bird/dinosaur feathers appear to be homologous to lobster swimmerettes, (and more distantly to caterpillar prolegs and mammalian mammae). Imagine that! Nature Rules!
PPS. Insect wings appear to be homologs to a vertebrate rib "shell", that is, the delicate forewings of a butterfly are equivalent evolutionarily to the hyperdense ribcage of a dugong, the aftwings of a moth to a sauropod pelvis, the fly's vestigial flight knobs to a giant blue whales vestigial pelvis.
Also interesting to compare human embryos and giant sauropod dinosaurs:
and the tentacles of squid ((4 + 1) x 2) with the typical prolegs of a caterpillar ((4 + 1) x 2)...
Church forests of Lake Tana, Ethiopia 'Trees are the jewels of God"
They function similarly to the European tradition of Royal Forest. Interesting the name of the island forests is Coptic Forest, similar to Coppice Forest.