Lecture Notes-03 Biology 1004

North Arkansas College

Topic: Origin of Adaptation/Natural Selection (Survival of Fittest)

Click below for discussions and other links.

http://www.talkorigins.org/origins/faqs-evolution.html

http://encarta.msn.com/find/Concise.asp?z=1&pg=2&ti=00C7C000

1. Lamark proposed adaptation; Inheritance of Acquired Traits.
2. As early as 547-611 BC, Amaxamander and Lucretius where already grouping species on the basis of similarities and differences.
3. Aristotle and Plato - Ladder of Life. Says that there are many similarities as well as differences among living species. This was the foundation of classification.
4. Darwin and Alfred Wallace were fathers of the explanation of minor differences among species on the basis of adaptation by natural selection. Eventually, Darwin wrote "The Origin of Species." He explained that adaptation and natural selection could be used to explain evolution in general and even possibly how man arose.

What must happen in order for natural selection and survival of the fittest to be illustrated?

1. There must be more individuals in a population than there is available food to support.
2. Competition for available food develops.
3. Adaptations occur to allow best competition for food.
4. These changes/adaptations must be passed on to offspring through gene(s).
5. Expressed more gradually in individual populations as they develop.

1. Plants from foreign geographic regions are accidentally brought in. They grow better, faster and reduce native plant populations.
2. Antibiotic resistance in disease producing organisms.
3. Sickle Cell Trait causes blood cells that don’t transport O₂ properly. Thought to evolve around equator to prevent multiplication of malaria parasite.

1. Peppered moth (England)

1. Originally, most moths were light color - trees they use had light colored bark. Birds of prey find their detection more difficult.
2. Following industrial revolution, smoke stacks produced "soot" that coated trees, etc. Light colored moths are easily visible on the dark colored three trunks.
3. Advantage to dark colored moths whose populations increased; found few light colored moths. In countryside, light moths predominate. More recently, laws have curtailed pollution allowing much less soot release. Tree bark has become light colored again. Population has shifted back to light moths.

2. Frogs in rain forest. If more females than males, the females grow male sex organs for breeding survival.
3. Salamanders (light gray) in Northwest U.S. began to migrate south to California. They reached valley and separated to opposites side of valley. Conditions on ocean side of valley were different from other side. Salamanders on coast side were dark blue. On the mountain side of valley, they developed differently (red spots and then orange). When they met again in Southern California, they were so different that they could no longer interbreed.
4. In Florida, roaches were exposed to bait (pesticide) called Combat. Some roaches developed resistance, reproduced and populations could no longer be controlled. Glucose in the bait became problem - resistant forms no longer had enzyme to use glucose.
5. In a meadow outside Carson City, NV, the Checkered Spot Butterflies always rested and laid their eggs on a native plant called Colinsia. Between 1981 and 1992, the meadow became infested with a weed called Plantago, and it became dominant. The Checkered Spot Butterflies began to lay their eggs on Plantago as they adapted. Scientists took caterpillars from eggs laid on Plantago (weed) and placed them on Colinsia, and let them mature on Colinsia. The mature butterflies still laid their eggs on the Plantago, rather than choosing Colinsia.
6. Antibiotic resistance in bacteria. In the 1940’s and early 1950’s, chemotherapeutic agents readily killed disease-producing organisms. In the late 1950’s, the Surgeon General said that all disease would be eliminated in the U.S. in 10 years. By the 1960’s, we had begun to see resistant forms of these organisms begin to appear. Today, we have some species that are totally resistant to most of the antibiotics.

In 1998, Cairns starved populations and found large numbers of population changed, rather than selecting a few cells - so they were able to grow on different substances (waste, cell components, etc.).

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