1.
Pax6 is a gene that regulates eye development in
the embryotic development. This trait also produces large amounts of cortical
cells which are beneficial to brain development. Pax6 forms the lens, cornea,
and olfactory epithelium. This trait is found in humans and in fruit flies.
Aniridia patients revealed that they had intragenetic mutation. These mutations
were found by defects of the Pax6 gene. Pax6 also helped development in the
nose, eyes, pancreas, and central nervous system in humans. Mutation due to
Pax6 results in eye development failure and pancreatic defects. Pax6 can cause
a fruit fly to grow an extra eye if this gene is placed directly in the antenna
of the fly. This gene has the same structure in both the fly and the human.
Studies show that a human and a mouse most recently show a common ancestor. The
fruit fly shares a common ancestor with both the mouse and the human but this
ancestor existed so long ago it would be hard to pin point a specific ancestor.
2.
Both a fly and a bird possess wings although
they function the same. The structure of the wings between a fly and a bird is
vastly different. An insect wings is actually formed in a sack during embryotic
development and is attached to their back, what strengthens the insects wings
are the veins running throughout its wings. A birds wing skeleton has some
similarities with a human arm. The bird has a shorter forearm and they possess
fingers as well. The bones in the wing are minor compared to the size of the
actual wing. It’s hard to say what common ancestor a bird and a fly might
possess but I believe if they had one it would be from the megasecoptea group.
Although this group is strictly insects fossils have been found with the same
shape and structure of a bird wing.
Wow, very in depth look at one gene that I didn't even know existed. Very interesting to learn that humans and fruit flies can have the same gene working within us to regulate eye development as well as other important areas. So it was the cortical cells that were the homologus trait for the Pax6 gene right?
ReplyDeleteThank you for your comment, The pax6 gene is the homologous trait between humans and fruit flies the cortical cells are just one part of the Pax6 gene. I apologize if I didn't clarify.
ReplyDeleteWhile I am impressed with your genetic information, keep in mind the definition of a homologous trait. Homologs will share a common genetic ancestry. That is the case here. But they will also exhibit different structural and functional differences based upon different environmental stresses, such as the wing of the eagle and the wing of a penguin (from the assignment example). You have presented the ancestry and discussed the similarities, but without focusing on the differences in this trait (and indeed the trait only seems to vary when something goes wrong), this is just a shared, inherited trait, not a homolog.
ReplyDeleteMuch better on your analog and good analysis on the ancestry. One of the key clues to knowing this is an analog is because we understand bird evolution very well, enough to know that bird wings arose in the process of birds splitting from reptiles, i.e., long after the split with insects split with organisms destined to become vertebrates.