Lesson 3 - Evidence of Evolution Flashcards
(9 cards)
EVIDENCE OF EVOLUTION
Scientists have been studying evolution for many years.
They have 5 key categories of evidence that support the theory of evolution by natural selection. They are:
- Biogeography
- Fossil Records/Paleontology
- Comparative Anatomy
- Comparative Embryology
- Comparative Biochemistry
BIOGEOGRAPHY
Darwin compared small areas vs. large areas
Small area- Galapagos Islands
Species on the island were more similar to related species on the closest mainland (Darwin’s finches)
FOSSIL RECORD/PALEONTOLOGY
Extinct species found as fossils most closely resemble living species in the same area SO one species MUST have GIVEN RISE to the other
- Older layers of rock contain simple fossils
- younger layers contain more complex fossils
- species BECOME more COMPLEX over time
Darwin observed armadillos on the Galapagos
Islands
TRANSITIONAL FOSSILS
Show links between groups of organisms
Example: Archaeopteryx- believed to be the first bird (150 million years old)
It is the INTERMEDIATE between birds and dinosaurs
COMPARATIVE ANATOMY (Homologous structures)
Homologous structures
body parts that are SIMILAR in
structure, but differ in function
ANALOGOUS STRUCTURES
Body parts with similar functions but
DISSIMILAR evolutionary origins
- don’t have a shared ancestral source.
Other Example: Wings of a bird and
butterfly
Vestigial Structures
Body part with no apparent, current use (can
give clues about ancestry)
Example-tailbone-primates have tails but we
don’t SO we MUST have had a common
ancestor with a tail
COMPARATIVE EMBRYOLOGY
In vertebrates, there is a stage where all embryos look SIMILAR
Time spent in the womb gets longer because more time is needed to develop more complex structures
Similarities in embryos suggest a common
ancestor
COMPARATIVE BIOCHEMISTRY
Species can be compared at a MOLECULAR level. The higher the number of similarities, the more closely related they are to each other
