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Ch 7 8 ppt 2010 student notes
- 1. Chapter 7 - Biological Diversity and Biogeography Case Study Purple Loosestrife
- 5. Photos by Ken Miller
- 7. Â
- 8. Reproductive isolation can occur due to mutations too.
- 10. Extreme hunting left only 20 Few individuals left – why?
- 21. © 2003 John Wiley and Sons Publishers Fig 7.6 A classical experiment with flour beetles.
- 25. © 2003 John Wiley and Sons Publishers Fig 7.7 The occurrence of freshwater flatworms in cold mountain streams in Great Britain.
- 28. © 2003 John Wiley and Sons Publishers Fig 7.10 Change in the relative abundance of a species over an area or a distance is referred to as an ecological gradient.
- 34. © 2003 John Wiley and Sons Publishers Fig 8.3 The major vegetation realms are also based on genetic factors.
- 37. © 2003 John Wiley and Sons Publishers Fig 8.13 Global distribution of the major land biomes.
- 39. Â
- 40. © 2003 John Wiley and Sons Publishers Fig 8.10 Evolutionary divergence among honeycreepers in Hawaii.
- 42. © 2003 John Wiley and Sons Publishers Fig 8.11 Idealized relation of an island’s size, distance from the mainland, and number of species. Pg 138
Hinweis der Redaktion
- Purple loosestrife = an introduced species A wetlands plant from Europe - like many species was released accidentally from ballast water in ships docked at port (seeds in water) Also introduced as an herbal remedy No natural enemies here, so spread Has eliminated many native plants that provide food and cover for wildlife in wetlands of Canada and the U.S. Began on the East Coast and has spread Very prolific, spread in water and by livestock that walk through mud that carries the seeds. 20,000 seeds per 1.2 square yards in some areas Tall plant so shades other native plants and blocks their light Livestock doesn’t like is to won’t feed on it. Reduces the carrying capacity of grazing areas Hard to kill. Regrows from roots if plant is cut, burned or sprayed Focus now is on bringing in natural parasites
- Greater evenness in a community appears more diverfse see pg 119 fig 7.3 In the second picture, is walking through the community would have good chances of seeing all the different species
- Most numerous groups, with most members know, are the insects and plants Many species have yet to be discovered, many in the tropical rainforests Why so many species? Seems to be related to competition
- Gray was introduced into GB because it was “cute” It is out-competing the Red Squirrel which is native In winter: Grays eat acorns from oaks. They do well since most of the areas have oak (It is the dominant large tree in GB) Reds may ago extinct in the next 20 years (if not….will be left to areas that do not have any oaks)
- Hutchinson is the scientist who first suggested this ide See flat worm stucy on page 125. Fig 7.6 Also barnacle example from bio book To save an endangered species we must make sure that all the life requirements for that species are present
- In 1876 A.R. Wallace suggested idea or realms: Nearctic = North America Neotropial = cental and south america Palaearctic = europe, north asia and north africa Oriental = indian subcontinent and malaysia Australian = aust
- Other examples = fish and marine mammals, birds and bats and
- Adaptive radiation: classic example is Darwin’s finches Species diversity and islands 1 and 2) smaller islands have fewer types of habitats also less likely to be found by migrants risk of extinction is higher for smaller pops and smaller islands because they can only support smaller pops (see pg 138) 3) Sources of species on islands = evolution and migration only farther away = fewer migrants Immigration and speciation rate - extinction rate = # of species on island Tends to maintain at a constant rate