Natural Selection Flashcards
Primary sources of evidence supporting evolution:
- The fossil record
- Comparative morphology
- Biogeography
Fossils and the fossil record
-Traces of past organisms that give a visual of evolutionary change over time
-Can be dated by examining of carbon 14 decay
Comparative morphology
Analysis of structures of living and extinct organisms
Homology
Characteristics in related species that have similarities even if the functions differ
Embryonic homology
Many species have similar embryonic development
Vestigial Structures
Structures that are conserved even though they no longer have a use
Molecular homology
Many species share similar genetic information
Homologous structures
Characteristics that are similar in two species because they share a common ancestor
ex. Arm bones of many species
Convergent evolution
Similar adaptations that have evolved in distantly related organisms due to similar environments
Analogous structures
Structures that are similar but have separate evolutionary origins
Ex. Wings in birds vs bats vs bees
Common ancestry evidence
- Membrane bound-organelles
- Linear chromosomes
- Introns in genes
Biogeography
The distribution of animals and plants geographically
Systematics
Classification of organisms and determining their evolutionary relationships
Taxonomy
Naming and classifying species
Phylogenetics
Hypothesis of evolutionary history
-Use phylogenetic trees to show evolution
To determine evolutionary relationships, scientists use
-Fossil records
-DNA, proteins
-Homologous structures
Phylogenetic trees
diagrams that represent the evolutionary history of a group of organisms, similar to cladograms except trees show the amount of time
Cladograms
-Each line represents a lineage
-Each branching point is a node
-Root is the common ancestor of all the species
Sister taxa
Two clades that emerge from the same node
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