{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

1323384764_CHAP_10_SPR

1323384764_CHAP_10_SPR - EVOLUTION/LECTURE1 Evolution(PCB...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
EVOLUTION/LECTURE1 file:///E|/CH10-ADAPTATION-SPRING-2008/CHAP_10%20SPR_2008.HTML[12/8/2011 2:53:48 PM] Evolution ( PCB 4674 ). Chapter 10. Studying adaptation: Evolutionary analysis of form and function Main topics of lecture: I: Introduction: 1.- All hypotheses must be tested: The giraffe's neck reconsidered 2.- Experiments and observational studies 3.- The comparative method II: Phenotypic plasticity: III: Trade-offs and constraints: 4.- Factors that limit adaptive evolution 5.- Female flower size in a Begonia: A trade off 6.- Flower color change in a Fuchsia: A constraint 7.- Shifts in a herbivorous beetle: Constrained by lack of genetic variation I: Introduction: 1.- All hypotheses must be tested: The giraffe's neck reconsidered 1.1.- How can a researcher rigorously test the hypothesis that a particular trait is adaptive? This is an important question in evolutionary biology, mostly because we showed in the previous lectures that other evolutionary mechanisms different from selection are also important in evolution. In this lecture will give an introduction on how researchers can detect natural selection in all of its forms. 1.2.- As we mentioned in previous lectures, a trait, or integrated suite of traits, that increases fitness of its possessor is called and adaptation and it is said to be adaptive . Roughly speaking, in order to demonstrate that a trait is an adaptation, we need first to determine what the trade is for and then show that individuals possessing the trait contribute more to future generations lacking it. 1.3.- Obvious explanations for adaptation are no so obvious!!! The traditional adaptive hypothesis for the origin of the giraffe's neck (to forage trees above the reach of their competitors) provides an example that no explanation for the adaptive value of a trait should be accepted simply because it is plausible and
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon