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Origin of Species: The Work of Charles Darwin

Origin of Species: The Work of Charles Darwin. James A. Van Slyke. Charles Darwin (1809-1882). Born the Fourth of Five children (two sons ) in Shrewsbury, England; same day as Lincoln Grew up in family of doctors Dr. Robert Darwin (Father)

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Origin of Species: The Work of Charles Darwin

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  1. Origin of Species: The Work of Charles Darwin James A. Van Slyke

  2. Charles Darwin (1809-1882) • Born the Fourth of Five children (two sons)in Shrewsbury, England; same day as Lincoln • Grew upinfamily of doctors • Dr. Robert Darwin (Father) • Dr. Erasmus Darwin (Grandfather; early theories about evolution) • Well-known as a traveler and scientist • Later became ill and was unable to travel • Married Emma Wedgwood; had 10 children

  3. On the Origin of Species (1859) • Worked on the book for 8 years • The term “evolution” not used in book • Gained acceptance in biological science • Would still take many years to demonstrate the process empirically • The theory was in place, but many of the causal factors were still missing

  4. On the Origin of Species • General observations of nature • Great variety of pigeon types • Distinguishing features; Interesting characteristics • Yet, all have a common origin in the rock pigeon of India • Breeding champions • Characteristics can be changed through breeding • Good dog = best breeding from other good dogs • Current example – Racing Horses • Subtle changes occur, both good and bad, as a species proceeds through time

  5. On the Origin of Species • General Observations of Nature • All organisms compete in the struggle for existence • Either as prey or predators • Competition for resources (water, food, space) • Competition for mates and survival of offspring • Struggle is not necessarily direct one on one competition or violence • Complex interplay between many factors • Interdependent relationship between species • Clover fertilization from bumble bees • Field mice are predators Cats are predators of field mice • Once disturbance in the chain can affect all species

  6. Natural Selection • Certain species traits enable organisms to survive and reproduce • Other traits may decrease survival in some populations • Variance in species traits will foster survival for some some and extinction for others • Dependent upon the species trait and the environment of expression • i.e. gills work great in water; not so great in the desert

  7. Sexual Selection • Certain traits may increase or decrease reproduction rather than survival • Male competition for female mates • Can be violent; brutal (two stags fighting) • Females may choose based on different forms of display • Bird songs; special feathers or colors

  8. Diversification • Different species will occupy different roles or ecological niches in an environment • A type of division of labor • Different species will adapt to different food sources, survival mechanisms, etc. • This will diversify the types of species present in any particular ecological system

  9. Variation • Natural selection works on small differences in traits • Instincts • Physical characteristics • Natural selection narrows the variation in character traits • Very slow process • “slow and gradual accumulation of numerous, slight, yet profitable, variations

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