Charles Darwin

Question 1

Evidence for evolution is used to prove that

Answer 1

• Life on Earth has changed over time

- All life has descended from common ancestors

Question 2

independent confirmation

Answer 2

when multiple, independent pieces of evidence point to the same conclusion

Question 3

Fossils

Answer 3

• are as old as the rock they belong to
• they are formed from sediment
• there are very few fossils for the number of species which shows that we know very little about earth

Question 4

Traditional way of classification vs. post evolution theory

Answer 4

Traditionally living organisms have been classified based on morphological and anatomical similarities.
Under the light of evolution: similarities due to the common ancestor.

Question 5

Evidence for anatomy: Embryology

Answer 5

• Related organisms have very similar developmental stages = inherited from common ancestor
• Embryos often go through stages useful to presumed ancestor but not to current organism - e.g. gill slits in mammals, reptiles, birds
• The more similar the stages, the more similar the organism

Question 6

Evidence for anatomy: homology

Answer 6

Homologies are similar (but modified) structures that are often put to very different uses in related organisms. That homologous structure was present in the common ancestor but diverged over time.
- this proved that all life came from a common ancestor

Question 7

Evidence from anatomy:

vestigial structures

Answer 7

Structures with no apparent use in an organism but is homologous with useful structures in other related organisms.

• this shows that life evolved from a common ancestor and that successful traits are inherited by descendants (but they may not use them)
• vestigial structures are homologous structures but it lost its function in one of the groups.

Question 8

Convergence- analogous structures

Answer 8

• structures that have similar functions and but very different anatomy
• the similarities are due to similar environments but do not demonstrate any recent common ancestry
• not used in phylogeny?

Question 9

Biochemistry and molecular evidence- not available to Darwin

Answer 9

Analysis of protein structure, immune responses, genetic sequences all show increasing differences as common ancestors become more remote
Can be used as evolutionary clock

Question 10

Comparative behaviour

Answer 10

• Behavior can also evolve
• Many behaviours are found in variations within one or a few lineages – correlate with anatomical differences
• Mating displays correlate with genetic differences (?)
• Small behavioural changes, sometimes controlled by a single gene, prevent similar - species from mating

Question 11

evidence conclusion

Answer 11

conclusion is that life has evolved over time. Now it is a question of HOW it has evolved over time.