2. Birds have evolved over the last 60-70 MY. To learn about their relatedness, we can use DNAsequences. Because DNA evolves at a relatively steady rate, gene sequences in two differentorganisms will accumulate sequence changes and become more different with time. The longer agotheir common ancestor was, the more different their sequences will be. However, some genes areunder more selection and so evolve slowly. Other genes are under less selection and so evolve quitequickly. Assuming that sites change linearly with time, we can calculate how many sites differ whencomparing genes between different species. For simplicity we'll assume we are comparing 1000bp ofsequence for each of these genes.Species comparedCanary and olive finchCanary and house finchCanary and zebra finchCanary and robinCanary and chickena. Why do the three genes differ in the number of variable sites between different species?CanaryOlive finchHouse finchZebra finchrobinchickenCanary# of sites that vary when comparing 2 sequencesElongation factor la Green sensitive opsin Mitochondrial cytb19340.0000.0080.0140.0350.0440.098113410Here is some (hypothetical) data that shows the fraction of sites that differ when comparing the greensensitive opsin gene across all possible pairs of the different species.Olive finch0.0080.0000.0140.0350.0450.097Housefinch841062350.0140.0140.0000.0350.0420.096Zebrafinch0.0350.0350.0350.0000.0430.099Robin1602807007507500.0440.0450.0420.0430.0000.100d. Why would the cyt b gene do a poor job of determining bird relationships?e. Why is the green sensitive opsin gene just right in this case?Chicken0.0980.0970.0960.0990.1000.000Sketch a simple tree that shows how these organisms are related to each other, based on this data.c. Why would the elongation factor la gene do a poor job of determining the relationships of thesebirds?

DNA sequences may provide information to the researchers if they have uncovered a new species.…

2. Birds have evolved over the last 60-70 MY. To learn about their relatedness, we can use DNA sequences. Because DNA evolves at a relatively steady rate, gene sequences in two different organisms will accumulate sequence changes and become more different with time. The longer ago their common ancestor was, the more different their sequences will be. However, some genes are under more selection and so evolve slowly. Other genes are under less selection and so evolve quite quickly. Assuming that sites change linearly with time, we can calculate how many sites differ when comparing genes between different species. For simplicity we'll assume we are comparing 1000bp of sequence for each of these genes. Species compared Canary and olive finch Canary and house finch Canary and zebra finch Canary and robin Canary and chicken a. Why do the three genes differ in the number of variable sites between different species? # of sites that vary when comparing 2 sequences Elongation factor la Green sensitive opsin Mitochondrial cytb 19 34 84 106 235 1 1 Canary Olive finch House finch Zebra finch robin chicken 3 4 10 Here is some (hypothetical) data that shows the fraction of sites that differ when comparing the green sensitive opsin gene across all possible pairs of the different species. Olive finch House finch 0.008 0.000 0.014 0.035 0.045 0.097 Zebra finch 0.014 0.014 0.000 Canary 0.000 0.035 0.008 0.035 0.014 0.035 0.035 0.035 0.000 0.044 0.042 0.043 0.098 0.096 0.099 Sketch a simple tree that shows how these organisms are related to each other, based on this data. Robin d. Why would the cyt b gene do a poor job of determining bird relationships? e. Why is the green sensitive opsin gene just right in this case? 160 280 700 750 750 0.044 0.045 0.042 0.043 0.000 0.100 Chicken 0.098 0.097 0.096 0.099 0.100 0.000 c. Why would the elongation factor la gene do a poor job of determining the relationships of these birds?

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter20: Development Of Evolutionary Thinking

Section: Chapter Questions

Problem 5TYK: Which of the following statements about evolutionary studies is not true? a. Biologists study the...