Darwin's work offers vital insights into today's world by showing how the living world is constantly changing. That perspective helps us understand modern phenomena like drug-resistant bacteria and newly emerging diseases like avian flu.

Darwin was born in England on February 12th 1809. He grew up during a time when scientific view of the natural world shifting dramatically. Darwin developed a scientific theory of biological evolution.

He was given credit for the theory of evolution, how modern organisms evolved over long periods of time though descent from common ancestors.

Darwin took a five year voyage, he mapped the coastline of South America, He planned to collect specimens of plants and animals. His observations concluded into 3 thing. One, species vary globally. Two, species vary locally. Three, species vary over time.

natural selection occurs in any situation in which more individuals are born that can survive, and there is variable fitness among individuals (survival of the fittest). Fitness describes how well an organism can survive and reproduce in its environment. Adaptation is natural heritable variation.

1.)patterns in the distribution of living and fossil species tell us how modern organisms evolved from their ancestors.
2.)Also there are patterns in which very distantly related species develop similarities in similar environments.
3.)Many recently discovered fossils form series that trace the evolution of modern species from extinct ancestors.
4.) Closely related species differentiate in slightly different climates.

Changes in the environment change the way species function over time to adapt to their knew conditions. Similarities and differences among homologous structures help determine how recently species shared a common ancestor.

Disruptive selection is natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle of the curve. Directional selection is when individuals at one end of a distribution curve have higher fitness than individuals in the middle or the other end of the curve. And finally, stabilizing selection is a form of natural selection in which individuals near the center of a distribution curve curve have higher fitness than individuals at either end of the curve.

The Isabela Island tortoise has a dome-shaped shell and a short neck. The hood Island Tortoises has a curved shell open around their long necks and legs, this enables them to reach the island's sparse, high vegetation.

Miller, Kenneth R., and Joseph S. Levine. Miller & Levine Biology. Boston, MA: Pearson, 2010. Pearson Success Net. Pearson Education. Web.