evolution - constancy & change. modern evidence for natural selection 1.fossil records –...
TRANSCRIPT
![Page 1: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/1.jpg)
Evolution- constancy & change
![Page 2: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/2.jpg)
Modern Evidence for Natural Selection
1. fossil records – organisms change over time
2. biogeography – related organisms in same area
3. comparative anatomy – homologous structures
4. comparative embryology – similar embryos
5. molecular biology – similarities in DNA, proteins
6. artificial selection – selective breeding
![Page 3: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/3.jpg)
Phylogeny & Molecular Systematics
• Phylogeny – study of evolutionary relationships
• Molecular Systematics – study of molecular structures (DNA, protein) to determine evolutionary relationships
*animals, including humans, and fungi, are more closely related to each other than either are to plants
![Page 4: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/4.jpg)
• Occam’s Razor (law of parsimony) - "All other things being equal, the simplest solution is the best."
• Used to justify a phylogenetic tree that represents the smallest number of evolutionary changes
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Occam’s Razor & Parsimony
![Page 5: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/5.jpg)
Comparison of hemoglobin
Cladogram (phylogeny)- shows ancestral relationships
![Page 6: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/6.jpg)
Cladogram
- primate DNA comparisons
![Page 7: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/7.jpg)
![Page 8: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/8.jpg)
Molecular Clocks• DNA or protein comparisons to
estimate the length of time that two species have been evolving independently
Molecular Systematics
![Page 9: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/9.jpg)
Primate evolution
• Humans have 99.99% similarity
• Humans and chimps have 98% similarity
![Page 10: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/10.jpg)
![Page 11: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/11.jpg)
“Ontogeny recapitulates Phylogeny"
The embryonic development of a species (ontogeny) is a replay of its evolutionary history (phylogeny).
- 1866 Ernst Haeckel
![Page 12: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/12.jpg)
Comparative Embryology (faked)
![Page 13: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/13.jpg)
Drawings vs. photographs
![Page 14: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/14.jpg)
Comparative Anatomy
![Page 15: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/15.jpg)
Animal developmental characteristics
p.371
•body plan
•symmetry
•body cavity
•digestive tract
•segmentation
![Page 16: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/16.jpg)
mono-, para-, or polyphyletic
monophyletic – all descendants
paraphyletic - not all descendants
polyphyletic - last common ancestor is NOT within group
![Page 17: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/17.jpg)
![Page 18: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/18.jpg)
Monophyletic includes the most recent common ancestor of a group of organisms and all of its descendants
Polyphyletic does not include the common ancestor
Paraphyletic includes most recent common ancestor, but not all of its descendants
![Page 19: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/19.jpg)
Restriction Maps
1717
1310
43
1. Gibbon is least similar; chimp is most similar.
![Page 20: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/20.jpg)
Skull Morphology
humandeer cat dog bear gorilla
brain size
teeth types
brain to face ratio
meat-eaters
mammals
herbivore
![Page 21: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/21.jpg)
Skull Morphology
humandeer cat dog bear gorilla
brain size
teeth types
brain to face ratio
meat-eaters
mammals
herbivore
![Page 22: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/22.jpg)
Restriction Maps2. Changes will go back and forth as
environment changes.
3. Neutral changes will accumulate.
4. Advantageous changes will accumulate more often.
5. Two closely related organisms will have fewer genetic differences.
![Page 23: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/23.jpg)
Animal Development& Phylogeny
![Page 24: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/24.jpg)
Animal developmental characteristics
p.371
•body plan
•symmetry
•body cavity
•digestive tract
•segmentation
![Page 25: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/25.jpg)
Tissue Organizatio
n
1. no tissue - no specialized fxn
2. tissue - specialization
![Page 26: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/26.jpg)
Body Symmetry
1. radial - looks same cut from any side at top
2. bilateral - looks same cut from 1 side at top
![Page 27: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/27.jpg)
Body Cavity1. acoelomate
- no body cavity, digestive tube connected to muscle
2. pseudocoelomate - partial cavity
3. coelomate - digestive tube separated from muscles
![Page 28: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/28.jpg)
Digestive Tract
1. protostome
- spiral cleavage
- blastopore-->mouth
2. deuterostome
- radial cleavage
- blastopore-->anus
http://www.mun.ca/biology/scarr/141993_Protostome_vs_Deuterostome.jpg..jpg
![Page 29: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/29.jpg)
Comparative Embryology• closely related organisms go through
similar stages in their embryonic development
*all vertebrate embryos have gill slits: – gill slits in fish form gills– human gill slits form the Eustachian tubes
connecting the middle ear with the throat
![Page 30: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/30.jpg)
Comparative Anatomy
![Page 31: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/31.jpg)
Vestigial Structures – pelvic bones in whale
- eye sockets in blind salamanders
![Page 32: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/32.jpg)
Convergent Evolution -similar solutions to similar “problems”
Analogous structures• similar functions, no evolutionary relationship;
different internal structure & development
*flight - bird vs bat vs insect
*reproduction - marsupials vs placentals
*aquatic vertebrates - dolphins vs fish
![Page 33: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/33.jpg)
Artificial selection
• breeding
![Page 34: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/34.jpg)
Artificial selection• pesticide resistance• antibiotic resistance
![Page 35: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/35.jpg)
![Page 36: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/36.jpg)
Natural Selection“survival of the fittest”?
![Page 37: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/37.jpg)
Charles Darwin • (1809-1882) British naturalist • 1831-1836 Voyage on HMS Beagle• collected specimens of fossils as
well as living; observed the various adaptations of plants and animals
• breeding experiments
• 1859 “On the Origin of Species by Means of Natural Selection”
![Page 38: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/38.jpg)
“Origin of Species” Key Points
1. descent with modification • all species evolved from ancestral species
and were not specially created; diverse modifications accumulated over millions of years
2. natural selection • mechanism of evolution; a consequence of
interactions between individual organisms and their environment
![Page 39: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/39.jpg)
Natural Selection Requires…
1. Variation - individuals within a population show variation in their characteristics
2. Overproduction / competition - environmental resources are limited
3. Survival / reproduction – only those best suited to environment will survive to reproduce and pass on favorable variations
![Page 40: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/40.jpg)
Historical Views of Origin of LifeCreationism (Judeo–Christian):
Earth is ~6000 years old and was populated by unchanging life forms made by the Creator during a single week
Greek philosophy (Aristotle ~350 BC):
scala naturae (scale of increasing complexity) – species were fixed in form, did not evolve
![Page 41: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/41.jpg)
Carolus Linnaeus• (1707 – 1778) Swedish
physician, botanist
• father of taxonomy — developed the binomial nomenclature system
• organized organisms into categories based on similar physical features
![Page 42: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/42.jpg)
James Hutton• (1726-1797) Scottish geologist
• proposed geological gradualism – change is the cumulative product of slow, continuous processes
*canyons are formed by erosion from rivers
![Page 43: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/43.jpg)
Georges Cuvier• (1769-1832) French anatomist
• founder of paleontology – study of fossils
• proposed catastrophism – periodic catastrophes result in mass extinctions; migrating species repopulate the area
![Page 44: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/44.jpg)
Charles Lyell• (1797-1875) geologist• “Principles of Geology”
proposed uniformitarianism – geological processes are uniform and balanced throughout Earth
*processes that build mountains are eventually balanced by the erosion of mountains by wind and water
![Page 45: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/45.jpg)
Jean Baptiste Lamarck
• (1744-1829) naturalist• evolution is driven towards
complexity and perfection (organisms became better adapted to their environments)
• 1809 proposed inheritance of acquired characteristics: – use and disuse
*giraffes
![Page 46: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/46.jpg)
Reverend Thomas Malthus
1. all species over-produce
2. competition for resources
3. only a fraction survive to reproduce
4. eventually populations reach carrying capacity
•(1766-1834) studied human overpopulation:
![Page 47: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/47.jpg)
Stephen Gould • 1972 proposed theory of
punctuated equilibrium- based on fossil record: little change occurs, then rapid localized speciation occurs
• exaptation – shifts in function of a trait during evolution*mammalian limb
![Page 48: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/48.jpg)
Michael Behe
• 1992 irreducible complexity(argument for intelligent design) – biological systems are too complex to have evolved through natural selection
– evolutionary pathways may contain one or more unselected steps
![Page 49: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/49.jpg)
The Subtleties of Natural Selection
• individuals do not evolve; populations do
• only heritable variations can be changed
• an adaptation to a set of conditions may be useful or detrimental, under different circumstances
![Page 50: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/50.jpg)
Modern Examples of Natural Selection
• Kettlewell - observed peppered moths
• Grants on the island of Daphne Major - observed shifts in the frequency of beak sizes over short periods of time
• Antibiotic resistance in bacteria
• How do genetic variations arise in nature?
![Page 51: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/51.jpg)
Industrial Melanism – Peppered Moths
•1848 Kettlewell’s observations – moths are darker in polluted areas
![Page 52: Evolution - constancy & change. Modern Evidence for Natural Selection 1.fossil records – organisms change over time 2.biogeography – related organisms](https://reader035.vdocuments.net/reader035/viewer/2022062713/56649cdb5503460f949a4fb2/html5/thumbnails/52.jpg)
1973 Grant - change in finch
beak size