Great question. Obviously, it would be
wonderful if we could regenerate body parts too.
To understand this issue, we need to go all the
way back to when each of us was just a fertilized
egg. At first that egg divides to make 2
identical, smaller cells. This keeps up until
we’re a solid ball of cells. At first, a cell
could turn into any kind of cell: a liver cell, a
muscle cell, a hair cell, or a brain cell. If the
ball of cells splits at this point, the halves
grow into identical twins.
Then the cells start to specialize. Imagine
that a bunch of squirrels started at the base of a
tree, then started climbing. Soon they would be
off on a bunch of different branches. If the
squirrels can only climb in one direction, they
could never change to a different small branch.
Something like that happens with cells when they
The embryo goes from being a solid ball to a
hollow ball. Then the tube that will be our
digestive system starts to form. At that point the
cells get more specialized. Some will
become cells that form the lining of things like
our gut or lungs. Other cells could become things
like bones, muscles, or blood. A third set will
become part of things like our outer skin or
nervous system. Once a cell has branched into
one of these three types, it usually can’t go
As development continues, cells get more and more
specialized. Each cell still has the entire set
of our DNA, but any particular cell will only
use a small part of the many “recipes” in the DNA.
A skin cell uses different genes than a brain
cell. The cells also send signals to each
other so that they can work together to form
things like our limbs. As the cells divide on the
bud that will become our arm, they have to signal
each other so that the arm gets to be the right
size and shape and so cells “know” whether
they are forming an elbow or a fingertip.
Unfortunately, when we lose a finger, for
example, the cells in our hands can’t seem to
“turn back time” and send cells out to make a new
Many reptiles cannot regenerate body parts
either, but some lizards and their close kin
can grow a replacement tail. The cells in the
stump seem to get a signal that they need to start
dividing to make a new tail. The new tail is
not the same as the old one. It has cartilage
instead of bones and does not have all the nerves
of the old one, but it works okay. Some lizards
can go through this regeneration multiple times.
Others will only regenerate once. Others never
If the lizard has low stress and plenty of food,
regeneration happens faster. I found a reference
that said 60 days for one type of lizard. I
recommend the article for learning about how
regeneration is different in reptiles and
amphibians and how they might help researchers
learn to help humans.
please lean more here .
Why do you think it helps lizards to have