evidence for evolution. fossil evidence- provides transitional links archaeopteryx- links reptiles...
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Anatomical EvidenceHOMOLOGOUS STRUCTURES
structures that are similar because they were inherited from a COMMON ANCESTOR
ANALOGOUS STRUCTURES
similar in function, but NOT inherited from a
common ancestor
NOTE: similar structure, but NOT always function!
NOTE: similar FUNCTION, but not STRUCTURE
More Anatomical Evidence:Vestigial Structures
Vestigial Structures are undeveloped structures that were functional in some ancestor, but are no longer needed in that organism.
BIOGEOGRAPHICAL EVIDENCEWhen we study the distribution of plants and
animals on the planet, we notice:Animals evolved differently in each of the
biogeographical regionsWe see evidence that as the continents drifted,
organisms were separated and evolved.
BIOCHEMICAL EVIDENCEAlmost all living things use the same
biochemical moleculesDNA, Protein, ATP
Vast diversity came about by only slight differences in the same genes
The more closely “related” the organisms are, the more similar their DNA
Patterns of EvolutionMacroevolution refers to large-scale
evolutionary patterns and processes that occur over long periods of time.
Six important topics in macroevolution are:
extinction adaptive radiation (divergent evolution) convergent evolution coevolution punctuated equilibrium changes in developmental genes
Punctuated EquilibriumOrganisms go through fast periods of change,
followed by long periods of no change (according to fossil record)
Mass extinctions:provide ecological opportunities for
organisms that survived result in bursts of evolution that
produced many new species
Patterns of Evolution: 1. Convergent EvolutionConvergent Evolution: When 2 or more
unrelated species become more similar due to similar adaptations to their environment.
Divergent Evolution: when related species become more different as they adapt to different environments
Divergent evolution leads to Adaptive Radiation
Patterns of Evolution: 2. Divergent Evolution-Adaptive Radiation
Sometimes organisms that are closely connected to one another by ecological interactions evolve together.
The process by which two species evolve in response to changes in each other over time is called coevolution.
Ancestral Mammals
Adaptive Radiation of Mammals
This diagram shows part of the adaptive radiation of mammals, emphasizing current hypotheses about how a group of ancestral mammals diversified over millions of years into several related living orders. Note that the dotted lines and question marks in this diagram indicate a combination of gaps in the fossil record and uncertainties about the timing of evolutionary branching.