We made it through our first 5 day week! This week, along with the previous week, we have been focusing discussions and activities around Big Idea 1- Evolution. We continued on with our anole virtual lab, started learning about how pocket mice evolved to have darker fur to camouflage with volcanic rock in New Mexico, and watched Bozeman Science’s video on speciation.
Thanks to the virtual lab on anoles, I was able to learn a lot more about speciation and evolution. Evolution happens at often times very slowly, but needs to be done when organisms are in vulnerable states because otherwise they will go extinct. We learned, during the lab, that anoles’ have different body shapes and leg lengths to better suit their niches and environment. For example, twig anoles have short legs to better hug onto twigs in trees, and canopy anoles have large toe pads to climb up leaves. Also, from this virtual lab, we were able to draw conclusions about how dewlap color relates to habitat location of anoles and that, generally speaking, lighter colored dewlaps would be possessed by ground anoles or anoles that like to be in darker areas, and darker dewlaps would be possessed by anoles that are in more sunny areas so they are easier for the females to see. I am curious to know how exactly the color of a dewlap can be altered and best suited for a habitat based on just the amount of light a certain anole is exposed to. Also, if a ground anole, for whatever reason, started spending an extensive amount of time in the sun, and was not reproducing because his dewlap color was to light, would it adapt to become darker? Or would the anole just never get recognized until he returned to a darker area?
In the middle of the week we watched a video by Bozeman Science on speciation. In the video, Andersen started off by explaining an experiment from many years ago about fruit flies being separated and contained. In this experiment, one group of fruit flies was fed only starch, and the other group only maltose. After 8 generations the fruit flies changed colors. The starch fed ones turned yellow, and the maltose ones turned red.The fruit flies were reunited, but would not mate with fruit flies that they normally would, because they are different colors now. This was an example of allopatric geographical speciation. Allopatric speciation is biological populations are isolated from each other to an extent that interferes with genetic interchange. We also learned about prezygotic and postzygotic reproduction barriers. Prezygotic is a prevention of mating or fertilization between different species and post zygotic is reproductive barrier that operates should interspecies mating occur and form hybrid zygotes. We also learned about temporal, mechanical, and behavioral isolation.While Bozeman’s video was very educational and easy to understand, there are plenty of concepts I still cannot grasp. What are the environmental and genetic conditions that promote speciation? What is the nature of speciation genes? Can speciation result from certain genes?
This week we learned about evolution and it’s building blocks and it effects and creates changes in organisms. We also learned about speciation and reproductive isolation and the role it plays in evolution.
“Lizard Evolution Virtual Lab | HHMI’s BioInteractive.” Lizard Evolution Virtual Lab. N.p., n.d. Web. 16 Sept. 2016. http://www.bozemanscience.com/speciation
Andersen, Will. “008 – Speciation.” Bozemanscience. N.p., n.d. Web. 16 Sept. 2016. http://www.bozemanscience.com/speciation