Evolution

Question 1

How is homology evidence for evolution?

Answer 1

• All quadrupeds have same limb plan (1, 2, LOB, 5)

- Have a transitional form for when quadrupeds emerged from fish

Question 2

What is an exaptation?

Answer 2

Something that evolved for one purpose but has been selected to be used for another purpose

• e.g. scales (protection) = feathers (thermoregulation and flight)
• e.g. swim bladders (floatation) = lungs (breathing)

Question 3

How is the genetic code evidence for evolution?

Answer 3

• Genetic code is used by all creatures
• Could be due to single origin
• Could be that DNA is the only code that works
• Arrangement of ribosomal genes is the same across all life
• e.g. hox genes orchestrate development and organise segmentation

Question 4

How is the fossil record evidence for evolution?

Answer 4

• Timezones have the same creatures

- Layer of ash at the same depth across the world

Question 5

What are evidences for evolution?

Answer 5

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• Hierarchical organisation of life
• Homology (1, 2, LOB, 5, bat wings and primate arms)
• Genes and genomes (only one genetic code)
• Convergent evolution (dolphins and sharks)
• Embryology (all organisms start off similar)
• Vestigial organs (appendix, snakes with remains of legs)
• Bodies aren’t perfect (vegas nerve, bind spot)
• Intermediate forms
• Biogeography (patterns of distribution not uniform, explained by plate tectonics)
• Fossil record
• Evolution in our lifetimes (MRSA and head lice)