1. Scientists use different lines of evidence to support common ancestry.
Evidence of Evolution
Scientists use different lines of evidence to support common ancestry.

2. Fossil Record

3. Definition: The history of life as documented by fossils
Fossil Record
Definition: The history of life as documented by fossils

4. How it works
It serves as a record for the progression of life through time
Not complete but it is enough to safely assume
Transitional Forms: show the intermediate states of ancestors

7. Biogeography

8. Biogeography
Definition: The study of the distribution of organisms around the world

9. How it works
Zoogeographic regions are characterized by the presence of specific groups of animals.
The greater the distance the more diverse animals there are
Similarities not related are due to coevolution

17. Homologies: Similar characteristics due to relatedness
Molecular Homologies
Homologies: Similar characteristics due to relatedness

18. Molecular Homologies
Definition: Similarities in the sequence of nitrogen bases or amino acids between different species
The more closely related 2 species are the more similarities in their DNA/amino acid sequences

19. How it works
DNA technology can indicate that species who look different morphologically are actually closely related.
Biologists can calculate how long ago a species branched off by measuring the rate of evolutionary change in DNA sequences

21. Who is most closely related to the bird?
Elephant
Dolphin
Crocodile
Bat
AAT
CGA
CCG
ATA
GCA
ATT
CAT
CCA
GAT

22. Anatomical Homologies

23. Anatomical Homologies
Definition: using similarities in body structure to determine relatedness between species
Examples: eyes, pouches, lungs, gills

24. How it works:
Homologous structures- structures in different organisms that look similar because they were inherited from a common ancestor
Analogous structures- structures that look similar but have different evolutionary origins

27. Analogous Structures

30. Homologous or Analogous?

31. Homologous or Analogous?

32. Homologous or Analogous?

33. Homologous or Analogous?

34. Homologous or Analogous?

35. Homologous or Analogous?

36. Vestigial Structures
Structures that are left over from previous ancestors that have no practical use

37. Developmental/ Embryonic Homologies

38. Developmental/Embryonic Homologies
Definition: Studying the similarities of embryological development of living things

39. How it works
Some embryos look similar even though adult forms looks different
Similarities in embryonic development between different species indicate that they may have evolved from a common ancestor

42. Time to check your embryo identification skills
Guess the Embryo
tion/guess-embryo.html