Lecture 3 - The Evidence for Evolution

Question 1

What are the evidences for evolution (4)

Answer 1

• geology
• homology
• biogeography
• domestication

Question 2

How old was Darwin when he went on his trip?

Answer 2

22

Question 3

Where was Darwin’s first stop?

Answer 3

Bahia

Question 4

What is the evidence that geology gives for evolution?

Answer 4

• Earth is old so there is time for evolution to occur
• Intermediate forms - we can see the small changes in lineages through transitional fossils
• the more recent a fossil is the more it resembles modern day animals (in younger strata vs old strata)

(Darwin found fossils of extinct mammals and giants)

Question 5

Homology description

Answer 5

Two separate species share or have similar parts or traits indicating that they are descended from the same common ancestor. Sometimes they have evolved to serve very different functions

Question 6

What are some vestigial structures in humans?

Answer 6

• appendix - digestion in ancestors
• ear muscles - used to move ears now we move our heads
• goose bumps - doesn’t actually help us create air pockets or appear bigger bc we lost outer coat
• tailbone - don’t actually have a tail

Question 7

Vestigial structures

Answer 7

features that are inherited from an ancestor but reduced in morphology and function

can be homologous to functional structures in related species

can be explained by the presence of functional traits in ancestors then followed by evolutionary degradation

Question 8

biogeography

Answer 8

the distribution of living things across the globe

Question 9

How does domestication show evolution?

Answer 9

• shows that there is a variety of different heritable traits within a species
• variation can be selected on (whether by nature or humans)

Question 10

homologous structures

Answer 10

structures that evolve from the same original structure but perform different functions or look super different in the current iteration.

Question 11

ecologically convergent

Answer 11

species filling the same niche in different parts of the world and they end up looking/behaving similarly

Question 12

Describe the Australian Biota (the animal)

Answer 12

In Australia there was no humminbird to eat the nectar of high nectar plants so a tiny marsupial started doing it, it is the only mammal that is not flying that eats nectar in the world

Question 13

Describe the Galapagos flightless cormorant as an evidence of homology and vestigial structure

Answer 13

• much smaller wings compared to mainland
• does not have to fly to eat, or defend from predators
• wings are high energy so got ‘‘rid’ ie made them smaller to spend less energy but still have the structure

Question 14

What can we learn about evolution from biogeography?

Answer 14

• species that are geographically close will resemble each other more
• geographically isolated areas will tend to have weirder organisms
• different groups of organisms will adapt to similar environment possibly in the same way