Since dolphins have deactivated genes for legs, could you get a dolphin with legs

Question

Dolphin DNA has deactivated sequences for legs. Could these be artificially reactivated resulting in a dolphin with legs?

Answer 1

Sophia J has it.  Just to add to her answer, more than one gene is typically active in the development of organs and limbs.  Simply turning off one gene that represses the expression of hind limbs will not result in a fully formed leg that looks like a whale's last land walking ancestor's.  What you would get is what we already get: partially formed leg bones and limb buds.  Many whales still have remnants of their hind legs hidden inside their body cavities anyway.  At most we'd get a whale with an additional pair of flippers as has been observed in at least one dolphin.

Answer 2

It'd be kind of the same as reactivating the DNA sequences in humans for building tails or gills. Not just pointless. Not just something that that is going to make the other dolphins sneer and laugh, but potentially dangerous. They would be less streamlined and wouldn't swim as well. By changing their shape to give them "back" their lost hindlimbs, you would also have to change the innervation at the base of their spines and their nervous system. Not a good plan.

By the way, whales do not have legs on the inside. They do have very small bones (well, small for a whale) sort of at the place where their hips might be located. If they had hips.

ps Star Trek rules

Answer 3

Are they not inside the dolphin already. Whales have primitive legs inside

Answer 4

Dolphins and whales can be found with rudimentary hind legs when the genes for limbs are turned on for a bit during development.  It's called an atavism when an ancestral trait that is not normally expressed becomes expressed in an organism.

A story of a Dolphin with extra fins where hind limbs would form can be found here:  http://www.underwatertimes.com/news.php?...

A photo of some leg bones taken from a whale can be seen here:  http://daphne.palomar.edu/ccarpenter/wha...