Evolution Chapters 13,14, & 15 Earth has millions of other kinds of organisms of every imaginable shape, size, and habitat. The variety of living things is called ___________________________. How did all these different organisms arise? How are they all related? Evolution = ____________________ o All living things share a common ancestor. o We can draw a Tree of Life to show how every species is related. Evolution: ________________________; the process by which modern species _______________________________________________ (common ancestors). Evolution… theory or fact?? o It’s _________! o The theory of evolution is an ______________________ of HOW evolution happens. Our understanding of this process is always ___________________. o Evolution is also a ___________ due to the huge amount of indisputable ____________________for its occurrence. History Lamarck believed genes were ____________________________________, and the use or disuse of body parts. He thought that if an animal ______________________a characteristic during its lifetime, it could _____________________ to its offspring (Inheritance of acquired characteristics). Hence giraffes got their long necks through ___________________________ _______________ to reach high branches. Charles Darwin o A young, British ____________________interested in biological __________________and how it occurred. o Toured the world from 1831-1836 on board the HMS ______________. o Took lengthy ____________________ of the different species found on the ___________________ Islands. Mainly of the different _________ of __________, and shapes of _______________shells found on various islands. o Published a book on his findings in 1859: The ________________________ by means of Natural Selection. Natural Selection Occurs under 5 main conditions: The ______________________ to the environment survives to ________________. Proposed by Charles Darwin as the driving _________ behind the theory of evolution. (1) Variation: _______________________________ within a species caused by mutations, and sexual reproduction. Adaptation: A variation that ________________an organism’s ability to ___________________and reproduce. Ex: Organisms of the same species that are faster, have bigger claws, or are better camouflaged are likely to survive ______________. (2) The _________________________________- Members of a population must compete for _________, __________, and other limited necessities of life; (3) competition. (4) Overproduction: _____________ offspring, must compete, some survive. (5) Survival of the fittest- Those most genetically “______” survive. Caused by __________________+ _________________________+ _______________________ + the _________________for existence Darwin’s Conclusions: 1. The diverse forms of life have arisen by ________________with ______________________________ from ancestral species. 2. The mechanism of modification has been _________________________________ working over _________________________________________. A Summary of Natural Selection: Only _____________________________ individuals survive and reproduce. From generation to generation, populations continue to change as they become better adapted, or as their environment changes. Darwin also proposed that, over many generations, adaptations could cause successful species to evolve into a ___________________________. Speciation: The formation of a new species.