This methodology gave way to

This methodology gave way to - in Character complexes or...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This methodology gave way to Upward classification by empirical grouping. It became apparent that the groupings of Linnaeus were not Natural . The bottom of a downward classification process often lead to groupings where members had clearly the wrong affinity. Darwin's discovery forced the thinking towards Descent from a common ancestor . It became apparent that these were the Natural groups that had been sought. What ultimately is the basis for upward classification? Characters . Can take varied forms: morphology, chemistry, behavior, ecology, physiology all could provide good characters. Characters have character states : we all have hair, but our hair is different color; we all have eyes but our eyes are different color. Character states may vary together
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: in Character complexes , or they may vary independently = Mosaic evolution of characters. Skin, eye and hair color all vary together in humans. Is this three characters or one (pigmentation)? Morphological and molecular characters may not evolve together, in a mosaic fashion (reading in section next week). Different characters may suggest different patterns of relationships (see fig. 14.3, pg. 377), again an example of mosaic evolution. Homologous characters = characters sharing a common genetic and developmental history. Ancestor and descendant are linked by intermediate forms having the same character. These characters are the basis of determining a true phylogeny...
View Full Document

This note was uploaded on 11/06/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.

Ask a homework question - tutors are online