BIO 4 Macroevolution notes - Lecture 4 - Macroevolution 1....

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

View Full Document Right Arrow Icon
Sheet1 Page 1 Lecture 4 - Macroevolution 1. macroevolution: evolutionaryu processes at bigger scale a changes in major morphological features b. tetrapod limb changes 2. transformation of characters: a. characters from ancestors are transformed 3. serially homologous elements: snakes have vertebrae (evolution in differentiation and number ofvertebrae\ a. in the evolution of mamalian lineage, teeth are simpler but evolved homologously depending on use (teeth of canine, and dinosaur) b. increasing size and complexity: evolution doesn't always work this way (humans lack fur - reduction of complexity) 4. evolutionary reversal: returning to ancestral state a. snakes are example: ancestor - no legs, then tethrapods - have legs, then snakes - no legs again b. parasites (louse): commonly related to fleas which have legs (but b ecause it reverts back to being parasites, it losses legs) c. simple doesn't mean ancestral!! while on the other hand, derived doesn't mean recent! 5. growth allometry:
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/25/2010 for the course BIOLOGY BIO153 taught by Professor Cordon during the Fall '10 term at University of Toronto- Toronto.

Ask a homework question - tutors are online