biology week 5 assignments

The Complexity of Life

How do you now suppose new species emerge?

There are four current theories regarding geographic Speciation- allopatric, Peripatric, Parapatric, and Sympatic 

During allopatric speciation, a population splits into two geographically isolated populations due to geographical change. The isolated populations then undergo genotypic and/or phenotypic divergence because they are living under different conditions. Peripatric speciation is actually a type of allopatric speciation that results from isolation. This isolation may be the result of geographic isolation or a single ecological event that terminates most of the population. With such a small gene pool, rare genes are passed down more often, which causes changes in the pre-existing species. During Parapatric Speciation species are not isolated by a physical barrier and instead co-exist yet do not mate across the entire population. The causation factors that contribute to individuals within the population to selectively breed remains unknown Sympatic Speciation sympatic speciation is another type of reproductive isolation. Reproductive isolation may be due to individuals coming into their mating seasons at different times or preference of where to find a mate.

Speciation also occurs through human cultivation and manipulation of the environment.

A rad article

http://www.simonsfoundation.org/quanta/20140604-evolving-with-a-little-help-from-our-friends/

Do you vote for the chicken or the egg?

I think it makes the most sense that the “chicken” egg came first, but that it was a result of speciation from another similar species. I also just like imagining ostriches giving birth to chickens and being totally confused.

biology week 4 assignments

Post your thoughts on how we view animal intelligence?

The belief that humans (or as I like to call us, manimals) are the most significant species on the planet is amazingly human centric. Unfortunately, this as the dominant perception for the last several centuries in the western world has left our imagination and perception stunted by shallow anthropocentrism. This is not to say that when I watch the newest you tube video of cats taking care of human babies that I don't get all weepy eyed! It is exciting to learn how we are similar- biologically and socially to other species. I love learning that we have memories like elephants and enjoy physical humor like orangutans.

Below is a funny little graphic I came across (of course, we occupy the center of the graphic).

Post a comment to a classmate's blog

@ Jessie

I just want to know why we don’t "need”  wings. Even if all we go were a cute little pair of fruit fly wings- i bet my standing asanas would be so much easier if I had the assistance of wings to hold me up.

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!