Dr. Ratcliff's Evolutionary Study
The current evolutionary model has all forms of life originating from one original single celled microbial organism. The transition from microbes to life took roughly 3 billion years. The transition is rather intriguing as cells go from individual organisms into one large codependent ones that work together to ensure survival. Yet despite the difficulty to make that leap, many different organisms have made it successfully.
Dr. Ratcliff wanted to study this very transition. In order to study it Dr. Ratcliff had to set up an environment which would put evolutionary pressure on brewer’s yeast cells, which are single celled organisms, to become multicellular. To do that, Dr. Ratcliff put lines of yeast in 10 different flasks of broth. Dr. Ratcliff and his team then let flasks shake for a day so that the yeast would settle. The next day a drop was removed from the flask and placed in a new one. This would select for yeast cells with a mutation that would lead to settling towards the bottom the fastest, as yeast from the bottom would be taken to a new flask and allowed to reproduce.
Several weeks later the yeast was beginning to fall to the bottom more quickly, and when Ratcliff observed the cells under a microscope he found that they had clustered together by the …show more content…
hundreds! Instead of drifting away after production, daughter cells began to cluster with parent cells in order to settle toward the bottom faster! These were proven to function as a unit as when one cell would be isolated it would reproduce in a similar manner to produce more clusters. The clusters would grow until they reached a specific size and would the break into “branches” that would then become new clusters and restart the process. The proof that the cells were acting as a body could also be seen from the cells in the links between the branches “committing suicide” to facilitate the reproduction process, something that they would not do if they were not functioning as a unit.
The experiment demonstrated that the “leap” to multicellularity is not as difficult as originally thought. Other cluster type organisms also exist, perhaps due to a similar process occurring in nature; one example being choanoflagellates, which also grow as clusters sometimes. While the lab conditions were set to select for that, thus speeding up the process, a situation pressuring for that in nature is not unreasonable.
Currently Dr. Ratcliff and his team are researching the mutations in the yeast genomes and monitoring their evolution.
On October 26, 2015 we had experimented with the fermentation of yeast in order to observe the effectiveness of fermentation when using different sugar molecules to facilitate the reaction.
To measure the effectiveness we measured how much of the sugar solution was lost to the reaction over a fixed period of time. The yeast uses the sugar in order to provide energy for the daughter cells when the parent cells reproduce. Like in Dr. Ratcliff’s experiment our experiment made use of the principles of fermentation to learn more about yeast. However, whereas our experiment sought to find more about the use of different sugars, Dr. Ratcliff’s sought to use it for reproductory
purposes.
Dr. Ratcliff wanted to study this very transition. In order to study it Dr. Ratcliff had to set up an environment which would put evolutionary pressure on brewer’s yeast cells, which are single celled organisms, to become multicellular. To do that, Dr. Ratcliff put lines of yeast in 10 different flasks of broth. Dr. Ratcliff and his team then let flasks shake for a day so that the yeast would settle. The next day a drop was removed from the flask and placed in a new one. This would select for yeast cells with a mutation that would lead to settling towards the bottom the fastest, as yeast from the bottom would be taken to a new flask and allowed to reproduce.
Several weeks later the yeast was beginning to fall to the bottom more quickly, and when Ratcliff observed the cells under a microscope he found that they had clustered together by the …show more content…
hundreds! Instead of drifting away after production, daughter cells began to cluster with parent cells in order to settle toward the bottom faster! These were proven to function as a unit as when one cell would be isolated it would reproduce in a similar manner to produce more clusters. The clusters would grow until they reached a specific size and would the break into “branches” that would then become new clusters and restart the process. The proof that the cells were acting as a body could also be seen from the cells in the links between the branches “committing suicide” to facilitate the reproduction process, something that they would not do if they were not functioning as a unit.
The experiment demonstrated that the “leap” to multicellularity is not as difficult as originally thought. Other cluster type organisms also exist, perhaps due to a similar process occurring in nature; one example being choanoflagellates, which also grow as clusters sometimes. While the lab conditions were set to select for that, thus speeding up the process, a situation pressuring for that in nature is not unreasonable.
Currently Dr. Ratcliff and his team are researching the mutations in the yeast genomes and monitoring their evolution.
On October 26, 2015 we had experimented with the fermentation of yeast in order to observe the effectiveness of fermentation when using different sugar molecules to facilitate the reaction.
To measure the effectiveness we measured how much of the sugar solution was lost to the reaction over a fixed period of time. The yeast uses the sugar in order to provide energy for the daughter cells when the parent cells reproduce. Like in Dr. Ratcliff’s experiment our experiment made use of the principles of fermentation to learn more about yeast. However, whereas our experiment sought to find more about the use of different sugars, Dr. Ratcliff’s sought to use it for reproductory
purposes.