Evidence for Evolution Evidence for Evolution Strongest line

Evidence for Evolution

Evidence for Evolution • Strongest line of evidence • Organisms arise from splitting of single species into 2+ Basic Pattern and constraints:

Evidence for Evolution: The Vertebrate Limb “What could be more curious than the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat, should all be constructed on the same pattern, and should include the same bones in the same relative positions? ” – Charles Darwin

Additional Examples of Homology

What is the most universal example of homology?

Evolution of the genetic code: “Universal” m. RNA Code Judson and Haydon. 1999. Journal of Molecular Evolution • Other codes work as well as our code • Having a unique code also offers some advantages – Can you think of any?

Evolution of the genetic code 1 3 2 4 6 7

Vestigial Organs – why are vestigial structures evidence of Cohn & Tickle common ancestry? Nature Limb bud in embryo ~4 days Femur Limb bud in embryo ~24 days

Gene’s aren’t totally inactive…

Vestigial Organs in Humans? Smith et al. 2013. Comptes Rendus Palevol https: //www. youtube. com/watch? v=3 l. Uq. Y 1 Aas. AQ

Evidence from the Fossil Record

Transitional Forms in the Fossil Record: Whales Ambulocetus https: //www. youtube. c om/watch? v=a 0 Ddg. S Dan 9 c Start 4 min From Gingerich et al. Science 2001

Evolutionary transitions of modern whales Present 10 MYA Modern toothed whales 20 MYA 30 MYA Rodhocetus kasrani skeleton 40 MYA Ambulocetus natans skeleton 50 MYA 60 MYA Hypothetical artiodactyl skeleton

Sinosauropteryx Evolution of Birds Microraptor Archaeopteryx

DATING THE FOSSIL RECORD - RADIOACTIVE DECAY § Data sets from different isotopes yield similar dates!

Long-term Selection Experiments: How high can we push oil? Two-way selection for oil-content of maize seeds. (After Dudley 1997)

Long-term Selection Experiments: Two-way selection for protein content of maize seeds. (After Dudley 1997)

Long-term Selection Experiments: Butt Bristles Six replicate lines of D. melanogaster selected upwards for abdominal bristle number. Selection was suspended at the points marked. (After Yoo 1980) From Falconer & Mackay 1996 Why did bristle number drop when selection relaxed?

Response to Artificial Selection: Do you think mutation played a role here? Draw the shape of the curve relative to the original population in each line (Introduction to Quantitative Genetics Falconer & Mackay 1996)

Baculum Score Experimental Evolution: toying with selective pressures Sexual Selection Ground squirrel Voles Simmons and Firman 2013. Evolution

Experimental Evolution: making evolutionary change predictable? • Evolution tinkers • Changes result within a population can only come from one of two sources – What are they? • Evolution should be random “If we could somehow rewind the history of life to the dawn of the animal kingdom, it would be unlikely that we humans would ever evolve” - Stephen Jay Gould https: //www. youtube. co m/watch? v= h 8 SZ 6 or 1 R XA - Swarming - Hyperswarming Ditmarsch et al. 2013. Cell Reports

Observation of Evolutionary Change in Natural Populations Observed changes in phenotype as a consequence of changing environments

African Balloon Vine Original pop

MAJOR LINES OF EVIDENCE FOR EVOLUTION § The proposed genetic mechanisms of evolution have all been documented experimentally. § Just as erosion is a fact in physical geology, natural selection is a fact in biology – it is a necessary outcome of heredity and variation. What are the major lines of evidence?