Adaptations and Survival An adaptation is a structure

Adaptations and Survival Ø An adaptation is a structure, behavior or functional. process Ø These help an organism to survive and reproduce in particular environment Ø Example: Ø Can camouflage you find the “hidden organisms” in the following slide?

Other Adaptations Ø Behavioral Adaptation § Hibernation in ground squirrel Ø Structural Adaptation § Sharp talons and excellent vision of owl § Thick leaves of buffalo berry that help to reduce the water loss on hot summer days. Functional Adaptation Heart rate slows during hibernation

How do These Adaptations Develop? Ø They are a result of a gradual change of characteristics over time ØA variation that helps an individual in a population is likely to be passed on from survivor to survivor Ø Some variations help and some do not, not all variations become adaptations!

Variation Within a Species

Biological Species ØA group of reproductively compatible populations ØHow does variation within a species occur?

Ø Organisms Genetics that reproduce sexually have a blueprint from both parents Ø Through this reproduction, particular traits are passed on to the new organisms

Mutations Ø Mutations are genetic changes that happen in DNA Ø Occur from mistakes that happen when DNA is being copied Ø For example: Your DNA has about 175 mutations compared to your parents. Ø Sometimes you notice mutation, other times it has no effect

Benefits of Mutation Ø Sometimes a mutation allows for a trait that has benefits especially in a changing environment – it will select which organisms will survive Ø A population will change in its ability to survive as the abiotic conditions around it will select those suitable to survive in the environment Ø Mutations may provide a new selective advantage Ø A Housefly with resistance to DDT A California ground squirrel that has a factor in their blood that helps them combat rattlesnake venom when bitten Ø

Natural Selection ØDepends on reproductive success – those that live longer reproduce more and, therefore, pass on their traits. ØOperates on a population, NOT on an individual ØNatural Selection can take time or can happen quickly Find an example of natural selection that happened quickly and one that happened slowly.