Evolution in Action
28/06/11 14:34 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Tue, 06/28/2011 - 14:34.
Yeast like Saccharomyces cerevisiae are well known to naturally form pseudohyphal filaments depending on the nutrient conditions in their environment. The filamentous Schizosaccharomyces pombe typically does not dissociate after individual cell division. Consequently, the formation of cell aggregates is already an inherent property of these types of fungi. The fact that some cells in Dr. Ratcliff's "snowflakes" die, most likely from competition for food and toxic products produced by neighbouring cells, is hardly a measure of cooperation amongst cells for the survival of the colony. Dr. Ratcliff's claims would carry a lot more weight if it could be demonstrated that there was an actual division of functions amongst the cells of the colony that benefited each of these cells, increased the survival time and size of the colony, or increased the total number of surviving cells in the population of colonies. With these types of adaptations, it would then be worthwhile to pin point the changes in the genes and proteins that are responsible for evolution to multicellularity.
Link to the original blog post.
Yeast like Saccharomyces cerevisiae are well known to naturally form pseudohyphal filaments depending on the nutrient conditions in their environment. The filamentous Schizosaccharomyces pombe typically does not dissociate after individual cell division. Consequently, the formation of cell aggregates is already an inherent property of these types of fungi. The fact that some cells in Dr. Ratcliff's "snowflakes" die, most likely from competition for food and toxic products produced by neighbouring cells, is hardly a measure of cooperation amongst cells for the survival of the colony. Dr. Ratcliff's claims would carry a lot more weight if it could be demonstrated that there was an actual division of functions amongst the cells of the colony that benefited each of these cells, increased the survival time and size of the colony, or increased the total number of surviving cells in the population of colonies. With these types of adaptations, it would then be worthwhile to pin point the changes in the genes and proteins that are responsible for evolution to multicellularity.
Link to the original blog post.