WEEK 2: History and Evolution of Life on Earth Part I

On the second week, we learned about evolution of life on earth part 1. We learned how macromolecules exist on this earth and the formation of eukaryotes and prokaryotes. As a summary, small inorganic compound that maybe had been brought by comets and asteroids from the outer space went through a chemical evolution and became larger organic compound. Referring to prebiotic broth hypothesis, the organic molecules formed near Earth’s surface. Then, the organic molecules polymerized into larger molecules such as protein and nucleic acid. Next, primitive RNA molecules were packaged within a membrane which called protobionts. 

 

Successful protobionts will grow and split. Distribute copies of their heredity to offspring. Coacervate is one of the possible protocell. It is a tiny spherical droplet of assorted organic molecules which is held together by hydrophobic forces.

 Natural selection at molecular level resulted in DNA. DNA is more stable and easy to pack. After that, from DNA, it became prokaryotes. At first, prokaryotes were chemoautotrophs which consumed organic molecules for both energy and carbon. Then, they became autotrophs because of evolution. They consumed light and similar to sulfur bacteria today. For instance, cyanobacteria, it acted like a chloroplast and released oxygen to the atmosphere. This lead to the extinction of many anaerobic organisms. Natural selection occurred, favour those prokaryotes that can tolerate with oxygen. Finally, eukaryotes formed. This is what I understand after I tried to read the notes and asked my friends about this topic. My lecturer also asked the class to do a mind map about this topic by using the terms that had been given on the student portal. This activity also helped me to understand this topic. Actually, I was not really agree to do this kind of activity because on that time I was not understand about this. I did not know how to relate all the mechanisms and how it connected each other but after I did the mind map, I could see the relation and the path from one to another. That activity also encouraged myself to look for information. If you do not understand about something and your lecturer pushed to do the mind map, it will trigger yourself to find an effort to understand about that lesson. This is from my personal view how some activities can give benefits to ourselves. I am still looking forward about this topic as I am afraid if what I understand before could be wrong at some points.

WEEK 1 :- Introduction to Darwin's Theory

A few weeks ago, I had a first class with Dr. Parameswari for cellular and developmental biology subject. In that first week, Dr. Parameswari had introduced to class about the theory of Darwin in evolution. Before this, when I was in foundation at UiTM, I had learnt about this theory but not really in detail. My lecturer on that time told the class even though some of the theories are not really make sense, but we just take it as a knowledge and to appreciate what has been done by those scientists on that time to bring the information about the evolution. It was exactly like what Dr. Parameswari just told the class on the first week. She said we come from different types of religion and have different opinions, so be open minded and take it as a knowledge. As we know, the most popular theory from Darwin is about humans came from apes. Of course some of us definitely not agree with that theory but after I tried to go more deep into the topic, I found it was interesting actually. There are many other theories from Darwin and not just that ape’s theory that have been found by Darwin.  Dr. Parameswari gave us a video about a lecture that tell us about the background of Darwin. How he could involve in this field and what was his circumstances that he needed to overcome in order to publish his book. What I got after I watched that video, I knew before Darwin came with all that studies in evolution, he was a medical student. It shocked me actually on that time because Darwin was also like other students who studied science, majority want to pursue in medical field but he quitted from medical school because he could not see blood and those kind of cringe visuals. On that time, there was no anesthetic drug for the patient, so the patient will be operated alive! I have seen this operation on Discovery channel about how they operated the patient alive. Then, Darwin went for a voyage at age 22 for 2 years but it became 5. On this voyage, Darwin came up with the idea that lands form change which led to his first great theory, formation of coral reefs. He also found fossil which is a giant fossil ground sloth. He knew there were sloths in South America and he saw these sloths but these fossils showed the sloths were in bigger sized like cow sized. At first, I could not understand about the formation of coral reefs led to the change of landforms. After that, I tried to watch the video again, the terms such as fringing reefs, I tried to google it and find the images. Finally, I could imagine the formation. Other than that, there are four sources for evidence which are fossils, geography, embryology and anatomy. For the anatomy, there are two structures which are homologous and vestigial. For natural selection, there are four main principles such as variation, overproduction, adaptation and descent with modification. Dr. Parameswari had gave an assignment in order to improve our understanding in natural selection. We need to draw comic cartoon about how the animals in the cartoon adapt with the environment and evolved into another species. In conclusion, even though I felt this topic a little bit tough to understand but after I became familiar with all the terms and activities, I felt the improvement in my understanding.