Lexicon of Arguments

 

I 189
Similarity/Mayr: not all similarities of organisms are based on homology: three kinds of characteristic changes can simulate homology:
1st Convergent evolution: independent acquisition of the same characteristic in unrelated lines of descent, e.g. wings in birds and bats.
2nd Parallel evolution: the same with related descent lines due to genetic predisposition for this characteristic, even if it was not phenotypically pronounced in the ancestors. For example, independent acquisition of goggles by a whole family group of flies.
3rd "Setback": loss of the same developed characteristic in several descent lines.
>Homology, >Evolution, >Convergence.
I 190
Similarity: Darwin regards it as one of the classification criteria because there is no absolute direct correlation between branching and divergence.
>Classification, >Criteria.
In some family trees, all branches diverge to the same extent.
Similarity/Mayr: must be determined as a first step, then the genealogy.
I 373
Def similarity: certain characteristics must occur together with other characteristics from which they are logically independent.
>Independence, >Method.
I 190
Taxonomy: Problem: inconsistent evolution of different groups of characteristics. This can result in completely different classifications. For example, larvae in comparison to adult individuals: can fall into completely different similarity classes.
For example, humans are more molecularly similar to chimpanzees than different species of the genus Drosophila among each other.
I 192
Categories/Mayr: there is no reliable definition for the higher categories. Higher taxa can be described very well: e.g. birds or penguins. But the category to which they are assigned to is often subjective.
>Categories, >Categorization, >Taxa.