Topic: Adaptations and Evolution C-Notes EQ: How do adaptations aid in the survival of a species?

Adaptation a characteristic that has developed over many generations to allow an organism to better survive in its environment.

Adaptations are important because they allow organisms to survive and reproduce.

Adaptations occur to populations, not individual organisms.

Adaptations can be either structural or behavioral.

Structural Adaptations Changes to the physical body of a population over time. Examples: – long neck of a giraffe – large ears of an elephant – floating leaves found in lily pads.

Internal Structural Adaptations Changes to internal structures over time. Examples: --gills in a fish – presence of hollow bones in birds – xylem used to transport water in plants

Behavioral Adaptations Changes to the innate behavior patterns of a population over time. Examples: – the unique songs of humpback whales – hibernation of bears – migration pattern of the monarch butterfly.

How populations respond to their environment is diverse. Some migrate, others hibernate. Others may store fat and energy in order to stay through a cold winter.

The Theory of Evolution » 1850’s: Charles Darwin described how organisms might change over time. » 5 years of observations on the Galapagos islands led to developing his Theory of Evolution. Galapagos Islands

Theory a statement used to explain a group of facts. Theories accepted by scientists are: – Repeatedly tested through experiments – Used to make predictions about natural occurrences – Can be changed over time as new evidence is discovered

Darwin presented his theory in his book: The Origin of Species

Darwin's theory is that things, and, in particular, life, evolves by a process which he called "natural selection."

Natural Selection Process by which organisms that are most suited to their environment survive and reproduce most successfully. Examples: Green beetles tend to get eaten by birds and survive to reproduce less than brown beetles do. Hairless rabbits die in the cold and can’t reproduce

Natural selection is possible because of genetic variation among individual organisms within a population. Over generations, traits that enhance survival of a species are naturally selected over those that do not. When all members of a population have the favorable trait, it is called an adaptation.

Natural selection has occurred to change virtually every species found on Earth.

In the Galapagos Islands off the coast of Ecuador, the Galapagos Medium Ground Finch has developed a beak shape that is very different from other finches found in the same islands.

Adaptations to the shape of a bird’s beak occurs due to different food sources.

Selective Breeding Caused by Human Influence on characteristics and behavior. By breeding only animals with the characteristics we want, we force the animal to pass this to future generations. Domestic Animals – Ex: Selectively breeding to produce more meat in animals. Plants: – Ex: Selectively breeding Corn to produce more food.

Selective breeding of domestic animals like dogs has led to incredible diversity from their wolf ancestors.