It took single-celled organisms about 3 billion years to evolve into multi-cellular organisms. In a laboratory at the University of Minnesota, brewer’s yeast cells can evolve primitive bodies in about two weeks. The human body has more than 200 types of cells, and each type has a specific job. Humans are a fine example of multicellular organisms. We have evolved from single celled organisms in order to adapt to the world around us. In this experiment, scientists raised brewer’s yeast, a single celled organism that feeds of sugar and budding off daughter cells to reproduce. The scientists placed yeast in 10 flasks of broth. They shook the flasks for a day then let the yeast settle. They then removed a drop of the settled yeast and transferred it to a fresh flask where the yeast continued to grow. In this experiment, natural selection would favor any new mutation that would let the yeast fall quickly. Yeast that remained floating would not be transferred into the new flask. After several weeks of repeating this process, the yeast began to fall faster, and it would form clouds at the bottom of the flask. After examination of the yeast under a microscope, the scientist discovered that the yeast was no longer growing as single cells. Instead, the broth was full of snowflake shaped clusters of hundreds of cells stuck together. They weren’t clumps of unrelated cells. Instead of drifting away, newly budded yeast cells remained stuck to their parents. By clumping together, these yeast cells fell to the bottom of the flask faster than the individual yeast cells. The clumps would grow until they broke apart, then those broken clumps would repeat this new form of reproduction. In nature, the process of natural selection wasn’t nearly as rigorous as the conditions in the laboratory. However, in nature, multicellular organisms were slightly favored over single celled organisms. As time progressed, organisms evolved into more and more complex beings, such as humans, which have trillions of cells in our bodies.
This article relates to the human race because it gives us information on how we came to evolve from single celled organisms. The leap from single celled life to multicellular life is nearly as big as the origin of life itself. This article also relates to me because we are currently observing the behaviors of yeast in our lab experiments. This article affects humanity in general because it gives us a greater understanding of our past, and it may give us some insight into the future of the human race. This article provides a very clear example of natural selection, the process by which humans came to be, and further proves the theory of evolution. Humans have shown how they can accelerate the process of evolution in yeast, now it would be interesting to see how they can accelerate the process of evolution in animals or plants.
I liked this article because it gave me a better understanding of the basics of evolution. I was surprised to see how a process that took 3 billion years in nature can be replicated in a lab in only 2 weeks. The author of this article gave a good description of the experiment that was performed, but he gave little background on yeast, a topic that most people don’t have a very good understanding of. Also, the author didn’t say much about the significance of this experiment Overall, it was a solid article that taught me a lot about evolution, natural selection, and the scientific process.
Zimmer, Carl. "Yeast Experiment Hints at a Faster Evolution From Single Cells." New York Times. 16 Jan. 2012. Web. 12 Feb. 2012.
Just finishing my classmate, Lucas Carneiro's, review on the NY times article called, "Yeast Experiment Hints at a Faster Evolution from Single Cells", I think that he did a phenomenal job summarizing the great article. One aspect that I thought Lucas did a good job doing was keeping the flow and splendor of his writing, especially in the beginning of his review where he gave a great introduction to the study of cells which really helped made the topic of cells easier to understand to the reader. Another thing I think Lucas did a good job doing was laying a refined and simpler step by step of the procedure taken place in the experiment. Lucas really made the steps clear and presented them in a fashion that was easy to read and to understand. A third thing I think Lucas did a great job doing was the incorporation of such a relevant article to the studies and classroom exercises that we have been doing in the Biology room just recently that have to do with yeast growth. This makes me feel a profound connection to the article and the experiment and makes just that much better, to read and for interest.
ReplyDeleteOne way I think Lucas could have made this better is by explaining in greater depth and detail exactly what the scientists came upon that led them to the conclusion about rapid cell formation as I was a little unsure. Another think for improvement could be other references to similar experiments and maybe other cases of lab simulated cell growth that’s rate is increased exponentially.
One aspect that impressed me deeply was how scientists can replicate billions of years of evolution in just a few weeks. It is truly astounding how far modern research and knowledge has increased and improved in just the past years.
My fellow classmate Lucas Carneiro read and reviewed the article titled, “Yeast Experiment Hints at a Faster Evolution From Single Cells.” I thought Lucas did a wonderful job at reviewing the article. I liked how he explained the experiment to us. This really enhanced our understanding of how these scientists reached a conclusion. I also liked how Lucas explained the results; through this one can understand what the results really mean instead of us just assuming what they mean. Finally, I really liked how Lucas related the article to himself but also to us through him.
ReplyDeleteOne thing I think he should have done differently was that he should of connected our experiment to their experiment. This would help in achieving full knowledge of their experiment since we are very familiar with ours. Also, I think that he should have expanded at the start on background information regarding cells; it would have made this more interesting to read.
One thing that really opened my eyes was that they are kind of doing a similar experiment to us. Although we may not have the exact procedure or question we still have similar tasks to investigate. That really gave me pride in our work. Lucas did an amazing job of reviewing. Kudos to you.
Lucas Carneiro did a great job of summarizing ‘Yeast experiment hints at a faster evolution from single cells.’ He especially did a wonderful job of explaining the experiment at each step, which made it easier for me to understand. I thought that Lucas did a great job of doing a review on such a relevant topic which we have just recently done in class. I also like the fact that he incorporated his view of the article which was interesting from another person point of view.
ReplyDeleteI think that Lucas could have done a better job of reviewing this article if he had incorporated our yeast experiment to his review.
I was not aware that yeast experiment are leading to faster evolution in single cells, so it was great to learn something new. I thought that the topic was something different compared to thers topic so it was good to use something different.