Evidence For Evolution

Question 1

Mitochondrial DNA

Answer 1

Only inherited from mother

Higher rate of mutation then DNA
mtDNA has been slowly diverging from original female ancestor

Amount of mutation is roughly proportional to amount of time passed

Question 2

Protein Sequences

Answer 2

Comparing type and sequence of amino acids in proteins (ubiquitous proteins - found in almost all animals)

Degree of similarity can be established

Difference between amino acids in a specific protein when compared to another animal is proportional to length of time and amount of evolution

Question 3

Embryology

Answer 3

Comparing early stages of embryonic development

Remarkable similarity between early stages of development in vertebrates.

Eg gill pouches and arches, two-chambered heart and similar brain development

Strong evidence for a common ancestry with later evolution along different pathways

Question 4

Homologous Structures

Answer 4

Organs that are similar in structure but used in different ways

Eg Forelimb of vertebrates: bones are arranged in similar ways even if in one animal it is used as a wing (bat) or another for running

Question 5

Vestigial Organs

Answer 5

Organs that have lost or changed function
common in vertebrate species

Eg appendix

Question 6

DNA

Answer 6

All living things use same DNA code - implies we are all related and have a common ancestor

Code in DNA of different species varies

Humans share very similar DNA to other primates 98% same as Chimpanzees