acclimation and adaptations

c. evolution example

cactus vs. euphorb. not same ancestors. both developed adaptations to living in desert ENVR such as waxy cuticle, chlorophyll in stem.

Whether or not trait is adaptive..

depends on the environment the organism finds himself at.

c. evolution example 2

Platypus: electro-receptors on bill to detect prey, paddle shapes snout. Both are phlogenetically distant

Example of acclimation

arctic fox. Thick fur, lives in arctic, responds to seasonal transition in drastic ways. Accumulates fat which helps with energy and provides insulation. Fur changes color (white coat), cache (hides) food. Curls up into tight ball when sleeping (conserves heat).

Trade offs

gave a good trait but reduced in other trait. i.e. giraffes have to drink...so they spread their legs which makes them vulnerable to predation and they can slip and break legs.

two themes for class

limited resources and trade-offs

adaptation (trait under selection can be)

morphological, physiological, behavioral. All connected. Once you have one, the doors open for enhancement (i.e. morphological leads to mutations which lead to physiological and behavioral changes. SHAPED BY NATURAL SELECTION

boundary layer

traps air close to organism that minimizes wind effects. or a region of unstirred air or water that surrounds the surface of an object.

so why...giraffes

Male giraffes fight for dominance via dominance. Mal that wins gets access to females. Males with longest neck wins and have more offpsring and that trait (long neck) is expressed. Genetic corollary so females have long nexks too. Still adaptation.

wooly lousewort

Thick layer of hair which produces boundary layer and keeps the plant 34oF warmer so that it can carry out cell division etc. when it's cold. (earlier than other plants-competitive advantage)

GIraffe

Why long necks? to reach top of trees of course. However observed: during dry season they instead of eating tall trees eat small bushes. Wet season when there is less competition for food, they actually eat tall branches. Also both sexes feed faster and most often with bent neck

evolutionary ladaptation

Will survive and reproduce. Environment drives selection (IMPORTANT). Results from natural selection. must be heritable or else they wouldn't be able to evolve. Increase fitness

Fox

acclimation because over lifetime it changes its phenotype in response to environment. THIS ABILITY IS AN ADAPTATION.

acclimation

an environmentall induced change to an organism's physiology. Also known as phenotypic plasticity.

common garden experiment

see if its acclimation or adaptation. use clones so little genetic variation. keep everything the same except vary temperature.

convergent ecolution

similar environments often select for similar traits. organisms converge on traits due to similar environmental pressures

are all traits adaptations

some say yes! Some generate hypothesis: does this trait contribute to survival/reproduction. So we don't really know unless we test them