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Before Darwin came Larmarckism

Lamarck realized that life was not fixed due to his fascination with the fossil record. Lamarck argued that when environments changed, organisms had to change their behavior to survive. This is true as organisms tend to evolve due to environmental changes and other factors. However, in the mechanism in while organisms evolved he was incorrect. He believed that evolutionary change seemed from use and disuse. 

Lamarck suggested that if a giraffe stretched its neck for leaves, the nervous fluid would flow into its neck and make it longer and this ability to have longer necks will be passed down through generations. 

[1]
Compared to Lamarck's theory of acquired variation, Darwin proposed the idea of inherited variation. Some giraffes would evolve to have longer necks, not by their neck fluid but through microevolution. These individuals would have an evolutionary advantage because they could feed on taller trees allowing them to have higher fitness thus yielding more giraffes with longer necks. 

 [1]
Lamarck also argued that life had begun through spontaneous generation. Spontaneous generation is the production of living organisms from nonliving matter which infers that life appears in sterile environments. 

Two experiments that disproved the experiments of spontaneous generation were Francesco Redi 1668 experiment and Lois Pasteur 1859 experiment. [2]
 [2]
In 1839, Schwann developed the beginning of Cell Theory: (1) All organisms are composed of one or more cells & (2) The cell is the basic unit of life in all living things. In 1858, Virchow added to Cell Theory, (3) all cells come from existing cells. It was then when Pasteur conducted the swan-neck flask experiment. 
 [3]
The timeline above provides information about disproving spontaneous generations and proving germ-theory. [3]

Sources: 

[1]http://www.zo.utexas.edu/faculty/sjasper/images/f17.1.jpg

[2] https://www.britannica.com/science/spontaneous-generation

[3] https://courses.lumenlearning.com/microbiology/chapter/foundations-of-modern-cell-theory/

Comments

  1. Dylan AlbersFebruary 12, 2021 at 5:11 PM

    I really liked your post! I also gave an example of the giraffes! That is probably one of the biggest things that he got wrong in his hypothesis.

    ReplyDelete
  2. CristinaFebruary 12, 2021 at 8:23 PM

    Hi Carmen, your blog post was great. I loved how you broke down why he was so wrong about giraffes, and when you added in the cell theory and Pasteur's experiment. Those are all fantastic examples and this was well written. Great job.

    ReplyDelete
  3. LibbyFebruary 13, 2021 at 10:49 PM

    Awesome use of examples for disproving spontaneous generation!

    ReplyDelete

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