On our field trip, we traveled to Muir Beach, near Mountain Tamalpais. On this trip, we were able to see multiple populations of Mimulus guttatus in different environments. Due to the different environmental pressures, these populations demonstrated different traits that correlated to adaptive pressures.
For example, the first mimulus plants we saw were exposed to high amounts of sunlight and had constant water supply from a fountain. This caused there to be flourishing populations that were also flowering, thus signaling a readiness of maturity and to pass on genes to next generations. The plants in this area were healthy enough and in a good position, so they flowered, and bees most likely acted as pollinators for these plants since the provide an ideal landing platform for bees and red spots on the petals that could be attracting the bees. We spoke of the likeliness that a pollinator would travel far to spread the mimulus’ pollen, and determined that the mimulus guttatus that were closer would be receiving those genes rather than further ones. This would mean that there is a high probability of inbreeding, which can be dangerous to the gene pool. We were also able to see what mimulus looks like in its primary stages of life in this area as another population began to flourish. It is also worth mentioning that the mimulus populations were usually found around horsetail and ferns.
We then traveled to a more shaded part of the terrain where a creek was found. After traveling up the creek, a population of mimulus guttatus was found, but the populations was not flowering. The reason for the lack of flowering can be explained through the location of the plants. They were located in a shaded creek area that would get flooded in a few months time and had very little pollinator traffic, thus, along with shortening of the days, the mimulus reacted to these cues by not reproducing. These populations are called sink populations and they will not be participating in breeding with any other populations.
These different populations are most likely not to be very connected, but it all depends on the distance that pollinators travel and the seed dispersal that occurs. Mimulus guttatus is a very diverse plant and continues to demonstrate the adaptive capabilities it possesses.