TEST 1 Notes bio1202

TEST 1 Notes bio1202 - What is Evolution and Adaptation?...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
What is Evolution and Adaptation? Chap 22 Descent with modification: A Darwinian view Two main ideas 1. Evolution is the change over time of the genetic composition of a population (the gradual appearance of all biological diversity). 2. Decent of modern organisms with modification from pre-existing organisms Evolutionary Adaptation - accumulation of inherited characteristics that enhance organism’s ability to survive in specific environments. Evolution in Historical Context- Darwin in early 1830s. Darwin published The Origin of Species in 1859. Fossils are remains/traces of organisms from the past many of which are found in sedimentary rocks formed from sand and mud that settle to the bottom of seas, lakes, and marshes. The new layers of sediment cover old ones and compress them into superimposed layers of rock called strata . Pre-Darwinian Theory of Evolution Lamarck (1809) proposed Inheritance of acquired characteristics Bodies of living organisms are modified through the use or disuse of parts of the body that are used extensively become larger and stronger, while those that are not used deteriorate. Ex. Giraffes stretched their necks to reach leaves on taller trees. These modifications are inherited by offspring This idea turned out to be wrong Evolution by Natural Selection Darwin and Wallace developed the theory independently Darwin- voyage of the Beagle Wallace- naturalist in Indonesia Natural Selection -The unequal survival and reproduction of organisms due to environmental forces, resulting in the preservation of favorable adaptations -Process “selects” from what is available in the gene pool -New characteristics are not created on demand Mechanism Behind Natural Selection: Flowchart pg 458 Artificial Selection Selective breeding of organisms to encourage the occurrence of desirable traits Analogous to natural selection Concept 22.3 Evolution is supported by an overwhelming amount of scientific evidence. Examples of Natural Selection
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Within a few weeks of treatment with the drug 3TC, a patients HIV population consists almost entirely of 3TC- resistant viruses. How can this best be explained? D. a few drug resistant viruses were present at the start of treatment, and natural selection increased potential. Natural Selection and HIV resistance Fossil Record Show change in organisms through time Change in types of organisms o Past organisms differ from present-day organisms o Many species have become extinct “Dawinists rarely mention the whale because it presents them with one of their most insoluble problems. They believe that somehow a whale must have evolved from an ordinary land-dwelling animal which took to the sea and lost its legs.
Background image of page 2
…A land mammal that was in the process of becoming a whale would fall between two stools -it would not be fitted for life on land or sea and would have no hope for survival.” Alan Haywood 1985 Homologous structures May differ in function, but have similar anatomy
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 15

TEST 1 Notes bio1202 - What is Evolution and Adaptation?...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online