Charles Darwin and Selection Chapter 15

Charles Darwin  Born in England on February 12, 1809—the same day as Abraham Lincoln  In 1831, set sail from England on the H.M.S. Beagle on a voyage around the world—main place of study was the Galapagos Islands.  On his travels, he collected evidence that led him to propose a hypothesis about how life changes over time  His hypothesis, now with a huge body of evidence is the theory of evolution.

Darwin’s Observations  Plants and animals were well suited to their environment.  He was puzzled by where different species live and did not live.  No rabbits in Australia and no kangaroos in England.  Collected and observed many different fossils.

Natural Selection  Struggle for existence—members of each species compete regularly to obtain the necessities of life  Fitness—ability of an individual to survive and reproduce in its specific environment  Adaptation—any inherited characteristic that increases an organism’s chance of survival

Natures Act of Evolution  Survival of the fittest—individuals that are better suited to their environment survive and reproduce most successfully  Natural selection—common name for survival of the fittest because of its similarities to artificial selection  Over time, natural selection results in changes in the inherited characteristics of a population. These changes increase a species’ fitness in its environment.

Natural Selection  What will help a species to move on?  Camouflage—assist the species to go undetected by predators  Mimicry—The resemblance of one organism to another or to an object in its surroundings for concealment and protection from predators

Our Influence on Evolution  Why would we artificially select?  Artificial selection— In artificial selection, nature provided the variation, and humans selected those variations that they found useful. In artificial selection, nature provided the variation, and humans selected those variations that they found useful.

Sexual Selection  Male  Male competition—   Males compete for access to females, the amount of time spent mating with females, and even whose sperm gets to fertilize her eggs.   Female choice—   Females choose which males to mate with, how long to mate, and even whose sperm will fertilize her eggs.

Picture Credits        rary/images/evo/mustardselection.jpg&imgrefur rary/images/evo/mustardselection.jpg&imgrefur rary/images/evo/mustardselection.jpg&imgrefur      peg peg peg 