City Creek Nature Notes – Salt Lake City

June 1, 2017

May 30th

Filed under: Woods Rose — canopus56 @ 5:12 pm

Evolution of Birds

7:30 p.m. Only a few birds in the first mile call in the late evening. Wood roses have opened from Guardhouse Gate to mile 0.2, but then stop blooming. More will open as late spring heat moves up canyon.

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Phylogenetic studies, based on advanced abstract algebra mathematics of shared genes, allowed Hackett and colleagues to reconstruct the evolutionary tree of major bird orders (Hackett et al 2008). Pacheco and colleagues added an estimated time dimension to that phylogenetic reconstruction of bird evolution based on assumed rates of changes in mitochondrial DNA (Pacheco et al 2011, Fig. 2 at 1973). They concluded that all of the current major orders of birds evolved beginning about 90 million years ago. While the first birds were first evolving, Utah and the canyon rode up the leading face of the Fallaron plate wave while a vast north-south mountain range rose in Nevada and western Utah (January 7th). Between 80 and 65 million years ago, those mountains eroded away as the crest of the Farallon Plate continued to migrate under Utah (id). These orders of birds existed before the meteorite KT boundary impact 65 million years ago. In this view, birds are essentially small dinosaurs that should have been killed by the KT extinction event. But those pre-impact orders survived the KT extinction event and diversified into the many species found today in the canyon (Pacheco et al).

The significance of the Pacheco finding is it contradicts the popular notion that the KT extinction event killed off the dinosaurs, including birds. Under the earlier explosive radiation theory, after the extinction event, only one or two Cretaceous bird orders survived, and during the Tertiary era, they radiated into the major groups seen today. Penny of Massey University, New Zealand, and Phillips at Oxford University discuss the contradictory evidence regarding whether dinosaurs where rendered extinct by the KT event as an example of faulty scientific thinking (Penny and Phillips, 2017). There were several possible models for evolution after the KT impact: only one order survived the impact and then explosively radiated; only a few orders survived and then radiated, or many orders survived and then diversified into new ecological niches post-impact. Penny and Phillips note that the originator of the KT impact hypothesis, Alvarez et al, provided substantial physical evidence that the impact occurred but no evidence supporting their claim that this resulted in the abrupt end of all dinosaurs. Nonetheless, the idea that the KT impact abruptly ended the dinosaurs took root. Penny and Phillips also note that some evidence exists that small dinosaurs less than 2 meters in length were well on their way to extinction prior to the KT impact. Conversely, small mammals are found in increasing frequency during the small period. This suggests that small mammals simply out competed small dinosaurs and over time because mammals do not lay vulnerable eggs and are more adaptable to a large array of habitats. In the face that competition, small dinosaurs became smaller, took the air, and evolved into birds. Preliminarily, Penny and Phillips suggest that slow Darwinian evolution is an equally plausible explanation for the evolution of birds as compared to explosive radiation after the KT extinction event, and they recommend a robust research program to better test the impact’s effect on the co-evolution of mammals, small dinosaurs and birds.

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On May 30th, 2013, the Salt Lake Tribune profiles Bowman Brown, a chef who specializes in creating dishes using only plants gathered from Utah’s lands, including City Creek Canyon. In City Creek, Bowman pointed out Indian parsley, wild onions, and mountain pepper grass as wild plant foods (id). On May 30th, 1993, Memorial Day, Jack Goodman of the Salt Lake Tribune, describes the 1926 construction of Memory Grove Park in City Creek Canyon. The Greek style temple in the park is a mediation chapel erected in memory of Ross Beason Jr. by his family, after Beason’s death in World War II. On May 30th, 1927, Governor George Dern dedicated a monument to the Mormon Battalion at the southeast corner of the Utah State Capitol grounds that overlooks lower City Creek Canyon and Memory Grove (Monument plaque visited May 2017). The sculpture was rendered by Chicago artist Gilbert Riswold.

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