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Chapter 2 - Section 2. Species Interactions. http://www.learner.org/courses/envsci/unit/text.php?unit=4&secNum=7. Chapter 2 - Section 3. “Survival of the Fittest”. Chapter 2 - Section 3. Natural Selection.
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Chapter 2 - Section 2 Species Interactions http://www.learner.org/courses/envsci/unit/text.php?unit=4&secNum=7
Chapter 2 - Section 3 “Survival of the Fittest”
Chapter 2 - Section 3 Natural Selection The unequal survival and reproduction that results from the presence or absence of particular “traits”. (Starburst Activity?)
r K Selection vs. Selection Which one has more to do with “Natural” Selection?
Artificial Selection • the intentional breeding of plants or animals (i.e. selective breeding). Selective breeding is a technique used when breeding domesticated animals, such as dogs, horses or cattle. Some of these animals will have traits that a breeder will want to preserve. • Genetically modifying organisms (GMOs) lead to the most rapid rate of evolution.
Chapter 2 - Section 3 Evolution • A change in the genetic characteristics of populations from one generation to the next. (The genetic change within a population over time) • A population with high genetic variation would result in the highest rate of evolution.
Chapter 2 - Section 3 Adaptation • An inherited trait that increases an organism’s chance of survival and reproduction in a certain environment.
Chapter 2 - Section 3 Mutation • the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of DNA. Which one is real?
Chapter 2 - Section 3 Mutation • the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations. • A mutation is a change in an organism’s DNA. • Mutations are not necessarily good or bad, but they are always random(not based on environment). • Mutations may be caused by environmental factors such as UV radiation. • Many mutations cause the offspring to die before they are born. • Mutations may lead to greater genetic diversity.
Chapter 2 - Section 3 Extinction • The primary causes for the current increase in extinction rates are: • Habitat Destruction • Overharvesting • Introduction of invasive species • Climate Change • The primary causes for species endangerment are: • Direct Exploitation • Commercial Harvesting • Introduction of exotic species • Pollution • When the last individual of a species dies. Threatened Endangered Extinct! • Scientists estimate that about 99% of the original species on Earth (including those before humans)are now extinct. Project Make a PowerPoint based on an Endangered Species of animal, insect or plant. Requirements Location: include population/habitat maps and migration routes Quantity: how many are left - in the wild vs. in captivity Causes: why are they threatened or endangered? Solution: how are they being protected / reproduced today? See “assignments” page of website for more information. Already done
Chapter 10 - Section 1 Biodiversity • Biodiversity: The number and variety of life forms in an environment. • Populations with high genetic diversity are better able to respond to environmental change than with lower genetic diversity. • Scientists have identified and cataloged approximately 2 million species on Earth. Estimates of the total number of species on Earth range between 5 million and 100 million, with the most common estimate at 10 million. • The average rate at which species go extinct over the long term, referred to as the background extinction rate, is very slow: about one species in a million every year. (With 2 million identified = two species per year). • Under conditions of environmental change or biological stress, species may go extinct faster than new ones evolve. Some scientists estimate that more than 10,000 species are currently going extinct each year—5,000 times the background rate of extinction. • Additional: Scientists estimate that about 99% of the original species on Earth are now extinct. • (Friedland page 5) Already in notes
Chapter 5 – (AP Textbook) Biodiversity Hotspots • Biodiversity hotspots. Conservation International has identified 34 biodiversity hotspots that have at least 1,500 endemic plant species and a loss of at least 70 percent of all vegetation. (Friedland: p.144) Already in notes