31. Evidence for evolution

Question 1

What is the simplest proof of evolution in macroevolution?

Answer 1

Organisms show phylogenetic relationships predicted by descent with modification

Extinct organisms also included in the phylogenetic tree

Question 2

What are the evidence for evolution?

Answer 2

• phylogenetic tree
• fossils
• mechanisms of evolution (?? find the clear list)

Question 3

Explain parallel and convergent evolution

Answer 3

Similar evolutionary trajectories (developing similar structures):

• parallel evolution (between related species)
• convergent evolution (between unrelated species)

Ex: all placental mammals are more closely related to each other than to Australian marsupials although evolution and structures are more similar between the pairs

Question 4

Explain the bad evolutionary design of male plumbing?

Answer 4

Male plumbing: testes used to be inside the body → two possibilities of ecolution: short vas deference (the tube connecting) or vas deference looping around ureter → bad design persists in males where vas deference is looped

Question 5

Whate are the examples of bad evolutionary design?

Answer 5

1. Male plumbing system
2. Laryngeal nerves

Question 6

Explain the bad evolutionary design of laryngeal nerves

Answer 6

In the evolution of other animals from fish - gil slit bones developed _into jaw and ear bone_s → langeal nerves developed to be looped around blood vessels → have to take a detour - go from the jaw into body cavity and back up to the brain → bad design

In humans around 30 cm detour but in giraffes - very large detour

Question 7

Explain speciation

Answer 7

Speciation - the evolutionary process during which new species are formed when diverging populations can no longer interbreed and produce fertile offspring

Seperate gene pools created

Question 8

What is an example for microspecies

Answer 8

Very similar

Question 9

Why chimpanzees aren’t evolving into humans?

Answer 9

• Not a progression but a family tree (have evolutionary relationships); nothing is evolving into something else - each species has its own lineage but share common ancestors

Recent evolution: gut bacteria evolved around 10 minutes ago

Question 10

Microevolution example by natural selection

Answer 10

Polution in 19th century in UK → peppered moths developed into different colout black from white because they hide on tree trunks → moths attacked by birds

Gene for the colour on gene 17 - the mutation identified as transposable element (gene moves around) - estimated mutation occurred in 1819

Question 11

Microevolution examples by natural selection (other)

Answer 11

• Pesticide resistance - very strong resistance of anti-malarial drugs due to strong selection

Pesticide resistance - similarly Colorado beetle

• Antibacterial resistance
• Evolution of crop-mimics: picking out weeds from crops - only similar looking remained interbread → mimic the appearance of crops

Question 12

Explain cancer as an evolutionary process

Answer 12

Selective pressures on cancer cells in different environments - different organs

Selective pressures when moving from one organs to other (metastasis) - in blood fight off immunity

Competition for resources favours very aggressive cancer cells

Question 13

Summary of the lecture

Answer 13