Evidence convergent evolution of antifreeze glycoproteins in fish biology essay
Antarctic notothenioid fish and several northern cod are phylogenetically distant in different orders and superorders, yet produce nearly identical antifreeze. The molecular evidence for separate ancestors is supported by morphological, paleontological and paleoclimatic evidence, which collectively: Independent evolution of distinct types of antifreeze glycoprotein AFGP and peptides AFP in various polar and subpolar teleost fish lineages testifies to the: The molecular evidence for separate ancestors is supported by morphological , paleontological and paleoclimatic evidence, which together indicate that these two: The evolution of antifreeze glycoproteins has enabled notothenioid fishes to thrive in the frigid waters of the Southern Ocean. Although successful, our paper provides clear evidence that the northern cod antifreeze glycoprotein gene originates from a non-coding region. We further describe the: Functionally similar antifreeze proteins and glycoproteins, AF GPs, were subsequently identified in numerous fish living in subfreezing marine waters. AFGPs evolved independently in the northern gadid cod fish, Raymond et al. 1975, VanVoorhies et al. 1978 and thus provide an excellent example of convergent, convergent evolution of antifreeze glycoproteins in Antarctic notothenioid fish and Arctic cod. Chen L, DeVries AL, Cheng CH. Proc Natl Acad Sci USA, 8 3817- MED. Eastman, JT Antarctic Fish, The ice-binding antifreeze glycoprotein AFGP circulating in the blood of Antarctic notothenioid fish allows them to avoid frostbite in their perpetually frigid state. This is crucial. These proteins were called antifreeze glycoproteins AFGPs. Eventually, several types of AFPs were discovered in fish from the Arctic and Antarctic regions. Although classified as different types based on their sequence and structure, AFPs possess equivalent properties that allow them to bind to ice and lower its freezing point. The antifreeze proteins were first discovered and so named because their function was clearly one that allowed fish to avoid freezing in ice-laden seawater. Freeze and, with the discovery of APs in insects and microbes, it has been suggested that they be called ice-structuring proteins. Clarke,