Evolution- Laila Bangwar & Lujane Pagganwala
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This document presents an overview of evolution through natural selection. It defines evolution as cumulative heritable changes in a population over time. It provides evidence for evolution through fossil records showing changes over generations, as well as examples of artificial and natural selection leading to changes in populations. Specifically, it discusses how overproduction of offspring combined with variation and environmental pressures results in natural selection of traits increasing the chance of survival, and gives examples of antibiotic resistance in bacteria and pesticide resistance in rats evolving through this process.
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Evolution- Laila Bangwar & Lujane Pagganwala
- 1. Evolution BIOLOGY PRESENTATION DONE BY: LAILA BANGWAR & LUJANE PAGGANWALA
- 2. What is Evolution “Defined as a process of Cumulative change in the Heritable characteristics of a population.”
- 4. Evidence for evolution by Fossil records • There are several ways of proving evolution through the process of natural selection. • Fossil records are one of the ways.
- 6. Artificial Selection • Another way to prove evolution is by artificial selection. • What is artificial selection?
- 8. Homologous anatomical structures • Homologous anatomical structures is another way that evolution is proven • What is Homologous anatomical structures?
- 10. Over-production of offspring • Many times populations over produce offspring, more then what the environment can handle or support. • Some organisms which do so are: -Plants -Mushrooms -Fish
- 12. Why the environment cannot support the over production of off springs • The environment cannot support all the offspring due to lack of availability of water and other nutrients in order for the offspring to survive.
- 13. Consequences of over-production • The result of overproduction causes a competition between the organisms in order to survive. Also known as the struggle of survival. • It could be explained as survival of the fittest, as Charles Darwin himself referred it, though it is much more complicated then just that.
- 14. Variation • Some members of a species show variation. • Usually those who sexually reproduce, show more variation
- 16. Natural selection • Charles Darwin’s most famous theory. • What is natural selection? • Steps involved in evolution by natural selection: -overproduction of offspring -Variation in offspring, both harmful and beneficial -environmentally adapted genetic characteristics -Passing on of favorable genetic characteristics -All this accumulates to result in evolution.
- 17. Examples of evolution-in response to environmental change • Evolution usually is a time consuming process, but sometimes natural selection may take place quicker, in months or decades, instead of a million years. • Two examples of natural selection could be: - Antibiotic resistance in bacteria - Pesticide resistance in rats
- 18. Antibiotic resistance in bacteria • Antibiotics are basically medications which kill bacteria. • In certain conditions, some bacteria may become resistant to the antibiotic. • This takes place due to two reasons which are: -Mutations -Plasmid transfer
- 20. Pesticide resistance in rats • Pesticides are those chemicals which are used to kill organisms that are pests such as rats. • Just like how bacteria become resistant to some antibiotics, pests (in this case, rats) become resistant to pesticides, in some conditions.
- 22. Evolution
- 23. Bibliography • Charles Darwin & Evolution. (n.d.). Charles Darwin & Evolution. Retrieved August 14, 2014, from http://darwin200.christs.cam.ac.uk/pages/index.php?page_ d3 • Introduction to Evolution. (n.d.). Vimeo. Retrieved August 17, 2014, from http://vimeo.com/19451460 • Ward, W., & Damon, A. (2007). Pearson baccalaureate: higher level (plus standard level options) : biology developed specifically for the ib diploma. Harlow, [England: Pearson Education.
- 24. THE END.