1. April 25, 2003
50th anniversary of DNA structure “educated guess”

2. © National Health Museum

3. © National Health Museum
© National Center for Biotechnology Information

4. EcoRV 5’-GAT|ATC-3’

9. A A B B C C
long branch attraction
true tree

10. = substitution rate t = time
after
red
green
blue
yellow
1/16μt
before
Lewis, Paul pp in Molecular Systematics of Plants II.

11. = substitution rate t = time
μt = expected # of substitutions / parking space over time t
after
red
green
blue
yellow
1/16μt
before
12/16 result in color changes
d = 3/4μt = expected # of color changes
Lewis, Paul pp in Molecular Systematics of Plants II.

12. = substitution rate t = time π = frequency of each car
after
red
green
blue
yellow
π2 μt
ππ μt
before
d = (1- π2 - π2 - π2 - π2 ) μt
unequal “color” frequencies

13. for nucleotide changes A G C T
d = 3/4μt d = expected # of nucleotide-changing substitutions
μt = 4/3 d # changes / site / time t
P (t) probability of seeing at least one change / site
P (t) = 1 - e-µt instantaneous rate of change
p proportion of changed sites
d = -3/4 ln (1- 4p / 3) “evolutionary distance”

15. P (t) = 1 - e-µt

17. d = -3/4 ln (1- 4p / 3) d = “evolutionary distance”
p = proportion of changed sites
e.g.
if p = 10/
d = .108
if p = 50/
d = .825
if p = 1/
d = .2326

19. d = -3/4 ln (1- 4p / 3)
.2326 = -3/4 ln (1- ((4*.2) / 3))

21. Reverend Thomas Bayes 1702-1761