Evolution and Biodiversity Changes in Species and Populations

Evolution Evolution is the change in a species over time.

Charles Darwin Darwin traveled around the world on the HMS Beagle. He found evidence from different places around the world which he used to formulate his Theory of Evolution. He collected his most important evidence from the Galapagos Islands off of Ecuador.

Natural Selection Darwin said that evolution happens through the process of natural selection, or survival of the fittest. Organisms that are the best fit for their environment will survive and reproduce, passing on their genes. This will change the gene pool of the population.

Classification of Living Things There are 8 levels of classification. They are: Domain Order Kingdom Family Phylum Genus Class Species

(Next to each classification, write the correct human classification in the inverted pyramid below.) Domain-------- Kingdom----------- Animalia Phylum---Chordata Class--------Mammalia Order-------------Primates Family-----------Homonidae Genus----------------------Homo Species----------------------Sapien

3 Domains and 6 Kingdoms Archaea Bacteria Eukarya Archae-bacteria Eubacteria Protista Fungi Plantae Animalia Prokaryote Eukaryote Unicellular Unicelluar Uni- & Multicellular Multicellular Multicelluar

Types of Natural Selection There are three major types of natural selection. Directional Selection Stabilizing Selection Disruptive Selection

Directional Selection The environment favors a trait found at one end of the curve. Species adapts until the trait becomes the norm for the population.

Stabilizing Selection Environment selects for a trait in the middle of the species variation, selecting against the traits found on the outer edges. Species loses variety.

Disruptive Selection Environment selects for traits that fall on opposite ends of the species spectrum. Species evolves into two distinct species over time.

In a population of beetles, the body colors of individual beetles range from light to dark. The graph below shows the distribution of body colors in the current population.  

IF the leaves of the trees begin to change over time, and become lighter, how will the curve of the graph change? Sketch and label the graph in the space provided. What is this type of selection called?

If the leaves of the trees begin to change over time, and become less light and less dark, how will the curve of the graph change? Sketch and label the graph in the space provided. What is this type of selection called?

If the leaves of the trees begin to change over time, and become more extreme light and dark but less average, how will the curve of the graph change? Sketch and label the graph in the space provided. What is this type of selection called?