Presentation on theme: "The Father of Evolution Charles Darwin 1809-1882."— Presentation transcript:
The Father of Evolution Charles Darwin 1809-1882
Charles Darwin Born in 1809, Shrewsbury, England Naturalist Studied Medicine Degree in Theology Buried in Westminster Abbey
After Cambridge, Charles was recommended for a surveying trip on the HMS Beagle. Darwin sailed aboard the Beagle for 5 years, working as a naturalist. The mission of the voyage was to chart stretches of the South American coast.
Row, row, row your boat! Voyage of H.M.S. Beagle Voyage of H.M.S. Beagle –5 year unpaid voyage –Darwin studied plants, animals, collected fossils –Found fossils of extinct animals that were similar to modern species. On the Galapagos Islands in the Pacific Ocean he noticed many variations among plants and animals of the same general type as those in South America.
The Galapagos Islands lie 500 miles west of Ecuador in the Pacific Ocean, directly on the equator. Many of Darwin’s conclusions were based on observations of wildlife in the Galapagos Islands. “Galapagos” means turtle.
Darwin was influenced by : Geologist Geologist Contribution: Contribution: –Earth is very old (much older than thought) –Earth has changed over time (constantly changing) Sir Charles Lyell 1797 - 1875
Another influential person Economist Economist Contribution: Contribution: –Populations have the potential to increase faster than the available food supply Thomas Malthus 1766-1834
M en u Menuenu Another influential scientist Botanist Botanist Contribution: Contribution: –Essay described evolution by natural selection Alfred Russel Wallace Spice Islands Home Page Alfred Russel Wallace 1823 - 1913
Darwin noticed there were several types of finches on these islands. In particular, Darwin observed something odd about the finches: they all looked like a bird he had seen on the South American continent.
In all, there were 13 types of finches, some species being confined to only one island.
The most distinct difference among finch species is their beaks, which are adapted for the specific diets available on the islands.
Darwin wondered if the birds and other animals had been created to match their environment, why didn’t these birds look like the birds of the African continent, since the environments of both the Galapagos and Africa were similar.
Darwin guessed that some of the birds from South America migrated to the Galapagos. Once on the islands, the birds must have changed over the years.
This would explain the numerous species of birds present. woodpecker finch cactus finch large ground finch
Warbler Finch Tree Finch Ground Finch Certhidea olivacea & C. Fusca Geospiza difficilis G. conirostris G. scandens Cacts Finch (nectar,eeds, blood) G. magnirostris Seed-eating Finch G. fuliginosa G. fortis Platyspiza crassitrostris C. heliobates Cactospiza pallida Woodpecker-like Finch Vegetarian Finch Insect-eating Finch Camarhynchus pauper C. psittacula C. pauper ( seeds & insects ) PHYLOGENIC TREE: A diagram showing the evolutionary history of a species of an animal. This tree has how many major branches?
TWO TYPES OF EVOLUTION: Convergent Evolution: process by which unrelated species become similar as they adapt to similar environments. Divergent Evolution: formation of new species from an existing species adapting to new environments. What type of evolution is a phylogenic tree?
After returning from the Galapagos and studying all the different types of plants & animals. Darwin concluded new concepts of change….
Darwin extended these principles to biology, which helped him form his theory of… …or Survival of the Fittest. Darwin called this… which means (change in species over time)
1. All species have genetic variation. Every species is different, even within itself. Look around you…are you all the same?
There is a constant struggle for survival. Examples are: DroughtFiresFloodsSnowstormsHurricanesTornadoes Other natural disasters 2. The environment presents challenges to survival.
3. Organisms produce more offspring than can survive. Competition exists WITHIN and AMONG species. food Within a Species Among a Species space mates food space
4. Individuals that are fit to their environment leave more offspring than those who aren’t. Darwin’s definition of fitness: an organism which has successfully adapted to its environment Organisms who possess favorable traits will leave more offspring. In other words, he who spreads the most genes wins! 1st
5. Characteristics of fit individuals increase in a population over time. Over time, genes for less favored characteristics will be eliminated from the gene pool. Example: giraffes and their long necks.
Therefore Darwin’s contributions: Provided evidence that species evolve In 1859, he proposed the Theory of Natural Selection to explain evolution (Survival of the fittest) Over time, change within species leads to the replacement of old species by new species as less successful species become extinct. Some evidence from fossils may prove that species on Earth have evolved from ancestral forms that are extinct. (species that have disappeared permanently.)
What is a species? One or more populations of individuals that can interbreed, producing fertile offspring. Speciation is the process by which new species are formed over time.
Equus, the modern horse, evolved from the dog-sized Hyracotherium. Notice it evolved from a four-toed front foot to the one-toed front foot of the modern horse.
Scientific Evidence of Evolution includes: Fossil Record Comparative Anatomy Embryology DNA & Proteins (Biochemical Evidence)
Fossil Record In order for fossils to form: Calcium must be replaced Burial must occur by sediment Usually occurs in swamps, mud, ocean floors, tar pits, etc.
. COMPARATIVE ANATOMY: Homologous structures are characteristics which are shared by related species because they have been inherited in some way from a common ancestor. For example, the bones on the front fins of a whale are homologous to the bones in a human arm and both are homologous to the bones in a chimpanzee arm. Turtle Alligator Bird Mammal
Analogous Structures In convergent evolution, organisms evolve similar features independently, often because they live in similar habitats. similar in function but not in origin and structure
VESTIGIAL STRUCTURES: structures that serve no useful purpose organs so reduced in size that they are nonfunctioning remnants of similar organs in other species ex: human tailbone, appendix, whale pelvis
EMBRYOLOGY Embryos of different species may appear similar in early stages of development ex: vertebrate development
3 COMPARATIVE ANATOMY Comparison of similarities in embryos can show: Relationship to a common ancestor