EVOLUTION

1. EVOLUTION By Karen Legg for EDU 580 Evolution Happens Lofton, Carol and Bill)

2. Evolution - Genetic change in a species over time. Theory - An assumption based on limited knowledge. Fact - Something that has been objectively verified.

3. DARWIN

4. Galapagos Islands: 13 major (above 14 square kilometers, 5 square miles); 8 smaller islands above .12 square kilometers. (.5 square miles); 40 named islets. Climate: Seasons: warm and wet from January to June, cool and dry (garúa) from July to December. Land Temperatures: High daily temperatures on land are usually in March at about 30° C, and lows come in September at about 19° C. Sea temperatures: Range from 16° C to 28° C, following high/low pattern of air temperatures. Rainfall: High rainfall comes February-April, over 70 mm per month; these are also the sunniest and warmest months,with the drier months being coolest and overcast. Education Workbook

5. Darwin’s Finches Evolution to Survive The birds beaks largely characterizes them in the different species. The variety that has a neat, sharp bill eats small insects. The variety that eats larger insects, has a broader bill, but still pointed back. Birds with heavier beaks eat small seeds, but still the beak is less blunt that the finch that eats the large seeds. http://www.horizon.fr/Galapagos/pinsonan.html

6. Natural Selection • DDDDirDirectional Selection • de • Shifts in environmental conditions, such as climate change or the presence of • a new disease or predator, can push a population toward one trait. • In periods of prolonged cold temperatures, for example, natural selection may • favor larger animals because they are better able to withstand extreme temperatures. • recessional SelectionStabilizing Selection • Sometimes natural selection acts to maintain traits by favoring the intermediate version of a characteristic instead of one of two extremes. An example of this type of selection, known as stabilizing selection, was evident in a study of the birth weight of human babies published in the middle of the 20th century. It showed that babies of intermediate weight, about 3.5 kg (8 LB), were more likely to survive. Babies with a heftier birth weight had lower chances for survival because they were more likely to cause complications during the delivery process, and lightweight babies were often born premature or with other health problems. Babies of intermediate birth weight, then, were more likely to survive to reproductive age. • ( Encarta) • coital Selection Continued…..

7. Natural Selection Disruptive Selection Sometimes natural selection favors two extremes, causing alleles for intermediate forms of a trait to become less common in the gene pool. The African Mocker swallowtail butterfly has undergone this form of selection, known as disruptive selection. The Mocker swallowtail evades its predators by resembling poisonous butterflies in its ecosystem. Sexual Selection Sexual selection operates on factors that contribute to an organism's mating success. In many animals, sexual attractiveness is an important component of selection because it increases the likelihood of mating. Sexual selection rarely affects females, because the duration of pregnancy and infant care limits the number of babies they can have. Males, on the other hand, have few limitations on the number of offspring they can father, and a male who produces many offspring has a high level of evolutionary fitness. Males of many species, then, must compete with other males to mate with females. Some males win females' attention more often than others and, as a result, pass their genes to more offspring. ( Encarta)

9. Peppered Moth ( Natural Selection) • In pre-industrial England, the peppered moth was located. • Almost all peppered moths were gray with dark flecks, but very rarely a black moth was seen. • The different colors of moths belong to the same species; they reproduce with • each other, and the color difference depends mostly on alternate alleles for a single gene. • The black moths were presumably produced by a • mutation: biochemical change in DNA that makes up the genes for a trait. • ( The University of Tennessee at Martin, Biology 391) Continued...

10. Peppered Moth Gray moths are well camouflaged on gray tree trunks; black moths stand out. It has been shown experimentally (by Kettlewell) that in areas with gray tree trunks, black moths are much more likely to be eaten by birds than are gray moths (presumably because black moths are much easier for the birds to see.) When industry developed in England, pollution from factories turned tree trunks in forests in industrial areas black. As illustrated here, on black tree trunks, black moths are well camouflaged; gray moths stand out. ( University of Tennessee at Martin, Biology 391) Continued…..

11. Black Moths! In industrial areas, because black moths avoided being eaten by birds, they survived better and therefore reproduced more (had higher fitness.) As a result, each generation, more and more of the offspring born came from black parents and inherited the black coloration, since the color differences between moths (gray versus black) are genetic. After many moth generations,almost all the moths in industrial areas were black. Black coloration is an adaptation to an environment with black tree trunks; that is, it has evolved through natural selection because black individuals have higher fitness in forests with black tree trunks than do gray moths. ( University of Tennessee at Martin, Biology 391)

12. Evidence for Evolution: 1. Fossil Evidence In 1799 an engineer named William Smith reported that, in undisrupted layers of rock, fossils occurred in a definite sequential order, with more modern-appearing ones closer to the top. Because bottom layers of rock logically were laid down earlier and thus are older than top layers, the sequence of fossils also could be given a chronology from oldest to youngest. His findings were confirmed and extended in the 1830s by the paleontologist William Lonsdale, who recognized that fossil remains of organisms from lower strata were more primitive than the ones above. Today, many thousands of ancient rock deposits have been identified that show corresponding successions of fossil organisms. ( Science and Creationism) http://www.fmnh.org/sue/default.htm (Field Museum Chicago)

13. When comparisons are made of the anatomy of structures which seem to have evolved very different functions, it can be seen that the process of natural selection has led to these differences. Homologous structures such as the forelimbs of a variety of mammals (eg human, cat, whale and bat) can be shown to possess the same skeletal elements, suggesting that a common ancestral forelimb has beenmodified for many different functions. Homologous structures such as those described above should not be confused with analogous structures (eg bat wing and insect wing), where evolution has given rise to anatomically very different structures which have similar function (aid in flying) where this function provides a survival advantage in a particular environment. ( VCE Biology Web Site) 2. Homologous Structures ( Science and Creationism)

14. 3. Analogous Structures • Structures that evolve separately to perform a similar function are analogous. The wings of birds, bats, and insects, for example, have different embryological origins but are all designed for flight.

15. 4. Vestigial Structures • These are homologous characters of organisms which have lost all or most of their original function in a species through evolution. • These may take various forms such as anatomical structures, behaviors and biochemical pathways. Some of these disappear early in embryonic development, but others are retained in adulthood. • All such characters can, be traced to the genes which code for such characters. Some genes no longer code for anything, and can be called vestigial themselves, or junk DNA.

16. Vestigial Structures Examples • http://www.livescience.com/animals/top10_vestigial_organs-1.html

17. 5. Embryology • Embryological development in many species is similar if not identical.

18. 6. DNA • Despite the great diversity of life on our planet, the simple language of the DNA code is the same for all living things. • Many of the same genes exist between different species

19. 7.Geographical Distribution • Major isolated land areas and island groups often evolved their own distinct plant and animal communities. • Unique biotic environments is that the life forms in these areas have been evolving in isolation from the rest of the world for millions of years.

20. Human Evolution (Planet of The Apes 20th Century Fox) Human evolution, a long process of change where people originated from apelike ancestors. Scientific evidence shows that the physical and behavioral traits shared by all people over a period of at least 5 million years. ( Encarta)

21. Human Origins Africa or Asia? Human path from Africa.( Encarta) Human fossils found in China. (Etler, Dennis A Center for the Study of Chinese Prehistory)

22. Movies • Evolution of People:http://www.pbs.org/wgbh/evolution/humans/humankind/index.html • Evolution of the eye:http://www.pbs.org/wgbh/evolution/library/01/1/l_011_01.html • The Dating Gamehttp://www.pbs.org/wgbh/evolution/sex/mating/index.html • Microbial clockhttp://www.pbs.org/wgbh/evolution/survival/clock/index.html

23. Bibliography and Web Sites Darwin’s Finches http://www.horizon.fr/galapagos/pinsonan.html Darwin’s Finches http://www.terraquest.com/galapagos/wildlife/island/finch.html Encarta http://encarta.msn.com/find/concise.asp?ti=761554675&sid=36#s36 Encarta.96 Encyclopedia Evolution Happens http://www.evolutionhappens.net/ Evolution The Evidence http://www.utm.edu/~rirwin/moth.htm Continued…….

24. Bibliography and Web Sites Fossil Evidence for Human Evolution in China Center for Human Evolution of Chinese Prehistory http://www.cruzio.com/~cscp/index.html Holt Biology Visualizing Life, Holt, Rinehart and Winston, Inc., 1994 continued……..

25. Bibliography and Web Sites Science and Creationism http://www.nap.edu/html/creationism/evidence.html# Sue at The Field Museum http://www.fmnh.org/sue/default.htm The Peppered Moth http://www.utm.edu/~rirwin/moth.htm Virtual Galapagos History http://www.terraquest.com/galapagos/history/intro.html