biology week 3 assignments

·      “99.4% of the most critical DNA sites are identical in human and chimp genes”
What do you make of this?

In 2003, researchers found that 99.5% of the “most critical DNA sites” are identical in human and chimp genes. This information has prompted many researchers to argue that chimps and humans should be brought together under the same umbrella genus.

The argument goes that in terms of life on Earth, humans and chimps are not that different and has prompted researchers to reconsider whether the ancestor of humans, chimpanzees, and bonobos evolved differently since our common ancestry split between 4 million and 7 million years ago. I am interested in the extension of this logic- to consider how genetic similarity confirms common ancestry for humans and different life forms. For example how much DNA do humans share with rats or mangos?   Also, what constitutes “critical DNA” and how does our human-centric perception shape what we consider is critical?

·      Check out the Prokaryotes, Eukaryotes, & Viruses Tutorial
http://www.biology.arizona.edu/cell_bio/tutorials/pev/page2.html


The tutorial was incredibly accessible. After reading the material I took the quiz, and received 5 out of 6. I did not know that viruses were not considered “living.”

Granted I am without a super special microscope that verifies that

viruses are merely genetic information surrounded by a protein coat. I am not sure that that ability to reproduce ought to be a determinate in identifying “life.”

·      Post a comment on one of this morning's discussions

I don't think that I understand autopoiesis- something that is capable of reproducing and maintaining itself, particularly when applied to systems. It seems to have a self- reinforcing logic that ignores external reference. Using the example of a eukaryotic cell and its various biochemical components further confuses me because we know that the cell interacts with the environment. How does autopoiesis consider changes to the cell brought on by the environment?  

·      Post a response to a classmate's blog

@hillary:

Gene expression related to embryonic development blows my mind!!! Seriously, with the rise in so many diseases and disorders we really do not put enough research into the environmental factors that are influencing expression! It dramatically changes the way we approach prenatal health, esp. in communities of color!