WEEK 3 - HISTORY OF LIFE PART II

History of Life

History of Life - Part II

      In week 3, I learned about systematics, taxonomy and classification of organisms. All living things are classified by characteristics into 6 kingdoms of life:

CHARACTERISTICS KINGDOMS	NUMBER OF CELL	CELL TYPE	MODE OF NUTRITION	CELL WALL
Archaebacteria	unicellular	prokaryote	autotrophic or heterotrophic	without peptidoglycan
Eubacteria	unicellular	prokaryote	autotrophic or heterotrophic or chemotrophic	with peptidoglycan
Protista	unicellular or multicellular	eukaryote	autotrophic and heterotrophic	most with cell wall
Fungi	mostly multicellular	eukaryote	heterotrophic	made of chitin
Animalia	multicellular	eukaryote	heterotrophic	absence
Plantae	multicellular	eukaryote	autotrophic	made of cellulose

Caralus Linnaeus: 

• Swedish Botanist
• first develop and publish first comprehensive and consistent classification system for plants and animal

ANALOGY VS HOMOLOGY

                              ANALOGY                                                     HOMOLOGY

          - similar function but different origin                  - similar structure and position but

          - not derived from a common ancestor                different function

                                                                                             - derived from a common ancestor

                                                                             

WEEK 2 - SELECTION IN ACTION + HISTORY OF LIFE PART I

Selection in Action

   In week 2, I learned the "Selection in Action" video content. This is the link http://www.hhmi.org/biointeractive/selection-action. The content is about comparing the artificial selection of dogs and corn with the natural selection of the stickleback fish.

        

     Darwin's key analogy said that artificial selection by breeders can produce major changes in body form:

variation

l

choose particular animals to produce

l

develop new breeds with increase or decrease in particular trait

Artificial selection has produced the food we eat and the pet we keep.

1) transformation of wild teosinte into modern corn

2) wolves into dog

               

                            

                                   

                              

      Besides, for SCL assignment this week is comic strip. My group chose rabbit to explain the adaption in a certain environment.




History of Life

History of Life - Part I

HOW DID LIFE BEGIN?

     Life started about more than 3.8 billion years ago is almost non-existent and then  have inorganic molecules. After that, organic molecules start to live from non-organic matter through a natural process on a pre-biotic earth which is called chemical evolution. Then, the organic molecules start to evolve into more complex life forms through a natural process of random mutation and natural selection.  

   

     

Prebiotic broth hypothesis

     Miller-Urey's experiment has established how organic molecules formed on primitive earth. So, once earth cooled this molecules start to form.

       Polymers evolved from small molecules into large molecules as the first genetic material formed was RNA which can self-replicate then evolved into DNA. RNA also evolved into protobionts and after that prokaryotes and eukaryotes formed.           

WEEK 1 - EVOLUTION AND CHARLES DARWIN + ENDLESS FORMS MOST BEAUTIFUL

Evolution and Charles Darwin

1809 - 1882

 

      In one of my subjects I'm taking which is Cell & Development Biology, the first topic I'm learned in week one is Evolution & Charles Darwin. Charles Darwin was an English naturalist and geologist, best known for his contributions to evolutionary theory. What is evolution?

     

      Evolution is change through time and it helps us to understand the history of life. There are some ideas on evolution prior to Darwin:

1. Aristotle - arranged organisms from simple to complex and visualized them as not perfect moving to perfectness.
2. Lamarck - evolution occurred by the inheritance of acquired characteristics and they are subject to a force which moves them from simplicity to complexity and environmental force fine-tune them to fir fit their biological niche more efficiently.
3. Charles Lyell - the earth must very old and it has been subjected to the same sort of natural processes in the past just like in the present time

      Darwin had proposed and demonstrated that all species of life have evolved over time from common ancestors through the process called 'natural selection'.

   

The long neck of the giraffe was not an adaption for reaching

the tops of the trees, but rather due to mutation , variation 

and sexual selection

       

        Alfred Russel Wallace was a British naturalist, explorer, geographer, anthropologist and biologist He is best known for independently conceiving the theory of evolution  through natural selection; his paper on the subject was jointly published with some of Charles Darwin's writings in 1858. This prompted Darwin to publish his own ideas in On the Origin of Species. 

My lecturer ask for watch this video " Endless Forms Most Beautiful" :
 http://www.hhmi.org/biointeractive/endless-forms-most-beautiful  

         There are some main idea that lead to Darwin's theory. He gathered evidence in the Voyage of the Beagle for 5 years.

1. Darwin observed variation among island species
2. Darwin realized species could adapt to their environment
3. Darwin observed fossil and geologic evidence of an ancient Earth 

There are four main principle of natural selection:

1. variation
2. overproduction
3. adaption 
4. descent with modification