1. EVOLUTION AND SYSTEMATICS

2. Biological evolution
is descent with modification

3. Biological evolution
Not merely a change over time X X

4. Central idea of evolution
Life has history (changed over time)
Different species share a common ancestor

5. Biological evolution Descent with modification
a change in gene frequency within a population over time
SCENARIO 1
SCENARIO 2

6. MECHANISMS OF CHANGE MUTATION
- A change in a DNA sequence, usually occurring because of errors in replication or repair

7. What causes mutations DNA fails to copy accurately
External influences can create mutations

8. MECHANISMS OF CHANGE
MIGRATION
GENETIC DRIFT

9. MECHANISMS OF CHANGE NATURAL SELECTION Variation
Differential reproduction
Heredity

10. Misconceptions about natural selection
It does not produce perfection
It is more of a process rather than as a guiding hand
It is not random

11. SOURCES OF VARIATION Random Mutations are changes in the DNA
Somatic mutations occur in non-reproductive cells and won't be passed onto offspring.
mutations do not "try" to supply what the organism "needs."
Gene flow (migration) is any movement of genes from one population to another and is an important source of genetic variation.

12. Sex-  can introduce new gene combinations into a population.

13. Family tree
Phylogeny
Clades
Hypothesis

14. Understanding phylogeny

15. Understanding phylogeny

16. misconceptions
Evolution produces a pattern of relationships among lineages that is tree-like, not ladder-like.

17. misconceptions
There is no correlation with level of "advancement."

18. MISconceptions
For any speciation event on a phylogeny, the choice of which lineage goes to the right and which goes to the left is arbitrary.

19. Misconceptions about humans
Humans did not evolve from chimpanzees. Humans are not "higher" or "more evolved" than other living lineages.

20. CLADE= MONOPHYLETIC
POLYPHYLETIC
POLYPHYLETIC

21. Clades are nested within one another — they form a nested hierarchy

22. Building the tree Characters heritable traits
Comparable across organisms
Morphology, behavior, genetic sequences
Homologous characters

23. Synapomorphies
Basis for grouping taxa together because they represent the product of a unique evolutionary event

24. Convergence - Stem succulence and “spines” in Cactaceae and Euphorbia spp.

25. Reconstruction of phylogeny
Selection of OUTGROUP
Coding of Characters
0- ancestral
Non-zeros- derived character
Reconstruction of phylogeny
Parsimony analysis

27. Principle of Parsimony
The cladogram that is shortest – has the fewest number of steps (character state changes) – is accepted as most probable,
because it minimizes the number of ad hoc hypotheses.
“Entia non sunt multiplicanda praeter necessitatem.”
(That does not exist which multiplies more than necessary.)
Of two or more competing hypotheses, the simplest one is accepted.

28. eXAMPLE 1 2 3 4 5 A B C
OUTGROUP

30. Strict consensus of 2,023 equally parsimonious trees
OUTGROUP
90%
Ophiorrhizeae
Strict consensus of 2,023 equally parsimonious trees
894 evolutionary steps
CI = 0.50
RI = 0.66
100%
Urophylleae
74%
A maximum parsimony (MP) analysis of the ITS data generated 2,023 equally parsimonious trees and a strict consensus of these trees resulted in a single tree
100%
Antherostele

31. Morphology of Antherostele
subsessile inflorescence
simple dichasium cyme
inserted at leaf axils
flowers unisexual (dioecious)
Sweet-scented
Rudimentary parts present
style
stigma
Female flower
Male flower

32. Using the tree Testing hypotheses about evolution
Learning about the characteristics of extinct species and ancestral lineages
Classifying organisms
CLADES-
groups of organisms that are all descended from a common ancestor

33. Pace of evolution

34. A jump in the fossil record can also be explained by irregular fossil preservation.

35. Relevance of evolution

36. Agriculture
Monoculture and the Irish Potato Famine: cases of missing genetic variation
populations with low genetic variation are more vulnerable to changing environment

37. Refuges of genetic variation: controlling crop pest evolution

38. Conservation
Inbreeding depression- matings between relatives are common

39. Using evolution to get the most bang from your conservation buck

40. MEDICINE Antibiotic Resistance: Delaying the Inevitable
Don’t use antibiotics to treat viral infections
Avoid mild doses of antibiotics over long time periods.
When treating a bacterial infection with antibiotics, take all your pills

41. HIV: The Ultimate Evolver
HIV closely related to other viruses.
- SIVs (simian immunodeficiency viruses)
- FIVs (the feline strains)
Primates with SIV and wild cats with FIV don’t seem to be harmed by the viruses they carry

42. The probability that the patient hosts a mutant virus that happens to be resistant to several different drugs at the same time is much lower
If you place resistant and non-resistant organisms in head-to-head competition in the absence of the pesticide or drug, the non-resistant organisms generally win.