Evolutionary Timeline and Evidence of Evolution

Question 1

George Buffon (1707-1788)

Answer 1

Examined animal body structures and their functions –> puzzled by anatomical features that seemed to have no purpose (ex. pigs toes that don’t touch ground)
Believed species had been created in more perfect form but had changed over time

Question 2

Carl Linnaeus (1707-1778)

Answer 2

Proposed that life had changed over time

Question 3

Eramus Darwin (1731-1802)

Answer 3

First to suggest that all life might have evolved from a single source - also proposed that life had changed over time

Question 4

Jean-Bapitiste Lamarck (1744-1829)

Answer 4

First to propose possible mechanism for evolution of species

Question 5

Lamarck’s Principles

Answer 5

Proposed that evolutionary change resulted from 2 principles:
1. Use and disuse: structures an individual used became larger & stronger, structures not used became smaller & weaker
2. The inheritance of acquired traits: individuals pass on to their offspring characteristic they had acquired during their lives

Question 6

Legacy of Lamarck

Answer 6

Principles proven to be false, but proposed the ideas:
- All species evolve over time
- A species evolves in response to the environment and becomes better adapted to that environment
- Changes are passed on from generation to generation

Question 7

Patterns of Change: Fossils

Answer 7

Formed when remains of organisms are gradually replaced by mineral deposits (rock) –> most are hard impressions in solid rock, sometimes entire organisms are preserved (in amber) and thin tissues like leaves are preserved as films

Question 8

Dating Methods - Relative Dating

Answer 8

Sediments are deposited in layers over time –> things in deeper layers are older than things in layers deposited on top (does not determine actual age)

Question 9

Dating Methods - Absolute Dating

Answer 9

Radiometric dating or tree rings (does determine actual age) –> radiometric dating: scientists measure the percentage of parent vs daughter isotopes in a sample as the radioisotope decays (ex. radiocarbon dating)

Question 10

Transitional Fossils

Answer 10

Fossils that show the link between “snapshots” provided by the fossil record and show characteristics common between two separate groups (ex. animals with gills and lungs show the link between fish and amphibians)

Question 11

Biogeography

Answer 11

The study of the past and present geographical distribution of organisms (used by Darwin and Wallace)

Question 12

Patterns in Anatomy - Homologous Structures

Answer 12

Structures that have common evolutionary origin –> are similar in form but may serve different functions in modern species (ex. bat wings and human arms)

Question 13

Patterns in Anatomy - Analogous Structures

Answer 13

Structures that perform the same functions but evolved from different origins (ex. butterfly wings and bird wings)

Question 14

Patterns in Anatomy - Vestigial Structures

Answer 14

When the function of a body structure or organ is reduced or removed over time

Question 15

Embryology

Answer 15

The study of the pre-birth stages of an organism’s development which can determine evolutionary relationships (ex. all vertebrates have paired pouches that develop gills or ears, and/or throats)