* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Evolution and Natural Selection
Sexual selection wikipedia , lookup
Sociocultural evolution wikipedia , lookup
Objections to evolution wikipedia , lookup
Natural selection wikipedia , lookup
Creation and evolution in public education in the United States wikipedia , lookup
Unilineal evolution wikipedia , lookup
Hindu views on evolution wikipedia , lookup
Punctuated equilibrium wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Evidence of common descent wikipedia , lookup
Creation and evolution in public education wikipedia , lookup
Acceptance of evolution by religious groups wikipedia , lookup
Transitional fossil wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Genetics and the Origin of Species wikipedia , lookup
Catholic Church and evolution wikipedia , lookup
Vestigiality wikipedia , lookup
Koinophilia wikipedia , lookup
Evolutionary history of life wikipedia , lookup
Evolution and Natural Selection How species change over time Evolution and Natural Selection GSE’s Genetic variations are passed on through reproduction LS3-9a Evidence for evolution illustrates how organisms are related LS3 -9b Natural selection leads to evolution LS3 – 9d Our understanding of evolution has changed over time LS3 - 9e Evolution The theory that organisms today developed from more simple life forms and have changed (evolved) over time Natural Selection The theory that states that those organisms best adapted to their environment have a better chance of surviving and reproducing Evolution Pre-Darwin Beliefs Earth was only a few thousand years old. We now know it is billions of years old. Neither the planet nor the species that inhabited it had changed since the beginning of time. We now know the planet has changed and, through fossils, discovered organisms have changed, as well. Evolution Pre-Darwin Beliefs Jean Pierre Lamark believed that organisms could change their traits during their lifetime by use or disuse. He thought that these traits could be passed on to offspring. Over time this would cause change in a species. Lamark was wrong Charles Darwin 1809 - 1882 Scientist credited with the Theory of Evolution & Natural Selection Voyage of the HMS Beagle – a 5 year voyage to South America and the South Pacific, collecting specimens, making observations and keeping a scientific journal of his findings Darwin’s Voyage Voyage of the Beagle What did Darwin find? The finches on each island in the Galapagos had different types of beaks. Voyage of the Beagle What did Darwin find? The tortoises on each island in the Galapagos had different types of shells. What was Darwin’s hypothesis? Darwin hypothesized that organisms had a common ancestor, but had adapted to their particular environments and changed over time. Darwin published his research in 1859 Natural Selection For natural selection to occur, there must be at least two varieties of a species. For example: the peppered moth Peppered Moths At the beginning of the Industrial Revolution in England, coal burning produced soot that covered the countryside in many areas What do you think happened? Before After Before After Evolution/Natural Selection White moths became easier to see, while the black moths became harder to see. The black moths were more likely to survive and pass on the gene for dark color to their offspring. Over time, the black moths have become more common. Evidence for Evolution: Common Ancestry Common Ancestry: If species evolved from a common ancestor, then they should share common anatomical traits Hawaiian Honeycreeper: family of birds in Hawaii that have similar skeletons and muscles, indicating they are closely related. Over time, their common ancestor evolved into several species, each with a specialized bill for eating certain foods. Just like Darwin’s finches on the Galapagos! Evidence for Evolution: Homologous Structures If animals evolved from a common ancestor, then they should share common structures – and they do! These are called homologous structures Evidence for Evolution Embryo Development What do you notice? List 2 observations Evidence for Evolution: Vestigial Organs Some organisms have structures or organs that no longer have a useful function. These structures or organs may have been useful to the ancestors of a species, but over time have evolved into what we term vestigial organs. Examples of Vestigial Organs Kiwi (flightless bird) Whales (hind leg bones) Humans (tailbone, appendix) Evidence for Evolution Fossils Fossils provide a look into the past Scientists can trace how a species has evolved by studying fossils Wrap Up the Evidence Common Ancestry Homologous Structures Embryonic Development Vestigial Organs Fossils Any Questions?