Week 2 Reflective Journal

In week 2, we learned more about natural selection. I watched a video entitled 'Selection In Action'.

What I learned from the video:

• Different genes control growth of different bones.

• Natural selection will lead to major changes over time.

• Artificial selection can drastically change traits in few generation.

Here's the video link : Selection In Action

One thing about the video that bothered me was about artificial selection where different breeds of dogs were used to produce a new breed that is a mixture of both the parent. There was a dog which happen to have its tongue hanging out of its mouth and I think the human that did the experiment was somehow responsible for making the dog went through that its whole life. Personally I think that artificial selection should only be done if it brings benefits to us, like in yielding high production or high quality crops. Artificial selection, like in cases for dogs, can cause genetic defects and health problems for the new breed if its not made from the right pair of parent.

I also learned about history of life in class. I learned about the requirements on Earth for life to exist and time line for the origin of life. 2 hypothesis were proposed ; prebiotic broth hypothesis and the asteroid theory. However, evidences support the broth hypothesis (chemical evolution) more.

I found the ability of scientists to discover information about the early cells and come up with many theories as very admirable. They are able to investigate and come up with many hypothesis and theories with supporting evidences.