Chapter 4 Biodiversity and Evolution - PowerPoint Presentation

1. Chapter 4 Biodiversity and Evolution

2. What is Biodiversity?It is the variety of earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystems processes such as energy flow and nutrient cycling that sustain all life.Biodiversity is a vital renewable resource.It is this biodiversity that sustains us and our economies.

3. The major components of earth’s biodiversityFUNCTIONAL DIVERSITYThe biological and chemical processes such as energy flow and matter recycling needed for survival of species, communities, and ecosystems.ECOLOGICAL DIVERSITYThe variety of terrestrial and aquatic ecosystems found in an area or on the earth.GENETIC DIVERSITYThe variety of genetic material within a species or a population.SPECIES DIVERSITYThe number and abundance of species present in different communities

4. Species; where do they come from?Biological Evolution by Natural Selection explains how life changes over time.Study of the Fossil RecordBiological Evolution (genes changing in populations)Natural Selection (certain traits out survive others)Major scientific theory that explains how life has changed over the last 3.5 billion years

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6. Tree of Life

7. Mutations and AdaptationsMutations and changes in the genetic makeup of populations lead to biological evolution by natural selection.Populations not individuals evolve by becoming genetically differentMutations change genes in cells Adaptive Traits improve ability to survive and most lead to differential reproductionGenetic Resistance allows organisms to tolerate chemicals designed to kill it

8. mutationadaptation

9. How did Humans become such a Powerful Species?Three Major adaptationsStrong opposable thumbsAbility to walk uprightComplex brainThese adaptations helped us develop technologies, tools, and devices, to help our survival.

10. Adaption through Natural Selection has limits.Can adaptations to new environmental conditions through natural selection allow our bodies to adapt to current pollution problems?NO, according to scientists in this field.First, environmental changes can lead to adaptations only for genetic traits already present in a population’s gene pool or for traits resulting from mutations.Second, even if a trait is present in populations, the populations ability to adapt may be limited by it’s reproductive capacity.Species that reproduce quickly adapt in a short timeSpecies that reproduce slowly adapt in a long time

11. Three Common Myths about Evolution through Natural Selection1. It is “Survival of the Fittest” not “Survival of the strongest”. (reproductive success)2. Organisms develop traits because they need or want them. (genes are already present)3. Evolution by natural selection involves some grand plan of nature in which species become more perfectly adapted. (appears to be random)

12. Geological Processes and Climate Change Affect EvolutionLocation of continents and oceans influence climate which determine where animals and plants can liveMovement of continents allows species to move, adapt, and form new species through natural selection, or become extinct. Earthquakes and volcanoes can separate and Isolate populations, or destroy and habitats wiping out populations.Climate change can occur rapidly killing off species and allowing other species to fill their roles. This also changes areas of habitability.Asteroid impacts have also affected evolution through natural selectionPlate Tectonic MovementEarth in 100 million years

13. How do new Species Evolve?Speciation – two species arise from oneSpecies evolve to a point they cannot reproduce successfullyGeographic Isolation – different groups of the same population of a species become physically isolated from one another for long periodsReproductive Isolation – mutation and change by natural selection operate independently in the gene pools of geographically isolated populations.Humans are playing an increasing role in the process of speciation by shuffling genes through artificial selection, and genetic engineering.

14. Speciation

15. Extinctionwhere an entire species ceases to existCan affect one species or manyEndemic Species are especially susceptible to extinctionBackground Extinction is where species disappear at a slow rateMass Extinction is where large numbers of species are wiped out Extinction is a natural process, but much evidence indicates humans are major contributors to premature extinction.Golden Toads located in Costa Rica’s Monteverde Cloud Forest Reserve have become extinct due to changes in climate. It’s habitat has dried up due to changes in climate.

16. Species Diversity The number of different species contained in a community.It is made up of Species Richness and Species Evenness.Communities with high species richness tend to have low species evenness. Communities with low species richness tend to have high species eveness. Examples:Tropical Rainforests have high many different species but there are only a few numbers of those speciesAspen Forests have a few different plant species but have large numbers of those species.

17. Species Rich Ecosystems tend to be More Productive and SustainableStudy by David Tillman and colleagues at the University of Minnesota found that communities with high species richness produced more, were more drought resistant, and were more resistant to insect invasion. They also consumed more carbon and nitrogen making them key players in those cycles.

18. Roles Species Play in EcosystemsEcological NicheFundamental Niche – the possible niche that a species can occupyRealized Niche – the actual niche or range in which a species actually existsWhere an organism lives and what it does in the ecosystem.Niches can be occupied by a native or nonnative species

19. Niche Breadth

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21. Generalists and SpecialistGeneralists are organisms that have the ability to survive in a wide range of habitats. This may include the ability to utilize a wide variety of food, shelter, etc.Specialists are species that survive in very specific habitats. They have adapted to eat very specific items and live in very specific habitats

22. The CockroachThe Ultimate SurvivorAround for 350 million years because it is a generalist.Eats almost anything, algae, dead insects, fingernail clippings, salts in tennis shoes, electrical cords, glue, paper, soap, their own dead and living.Can live without food for a month and survive on a drop of water from a dishrag for a month. One species can be frozen for 48 hrs and still survive.Have sensitive antennae and can respond faster than you can blink an eye.Have compound eyes each with 2000 lenses compared to the one lens in each human eye.Can detect poisonsProduce up to 10 million offspring in a year helping them develop genetic resistance really quickly.

23. Indicator SpeciesServe as biological smoke alarms.Indicator species provide warnings of damage to a community or ecosystem.Trout are only present in clean highly oxygenated waters.Birds and Butterflies are highly susceptible to pesticides and habitat fragmentation.Canary in the coal mine

24. Importance of AmphibiansAmphibians are sensitive environmental indicatorsThey eat more insects than birdsThey are a vital food sources for other organismsThey are genetic storehouses for pharmaceutical products. Painkillers, antibiotics, burn treatments, and heart diseaseAmphibian populations have been declining across the globe. They are susceptible to the following:Habitat fragmentationProlonged droughtPollutionIncreases in UV radiationParasitesViral and Fungal diseaseClimate changeOver hunting

25. Keystone and Foundation SpeciesKeystone Species – have a large effect on types and abundances of other species in an ecosystems. Example: AlligatorFoundation Species – play a major role in shaping communities by creating and enhancing their habitats. Example: Elephant

26. Protecting SharksSharks remove injured and sick animals from the oceanSharks almost never get cancerSharks have highly effective immune systems which allow wounds to heal without becoming infectedMedia portrays sharks as people eating monsters.A few species of sharks injure approximately 60-100 people worldwide annually.Poverty kills 11 million, tobacco kills 5 million, and air pollution kills 3 million people each year.Ecological studies have shown that declines in shark populations have led to declines in bay scallop populations in the Atlantic Ocean.

27. Species Richness on IslandsRefered to as Species Equilibrim Model or Theory of Island BiogeographyIt is determined by 2 factorsRate at which new species immigrate to the island Rate at which species become extinct from the islandModel projects that at some point these two factors balance and determine the islands average # of species over time.Small islands tend to have fewer species and fewer resources. Therefore, low immigration and high extinction rates which are opposite for large islands.Islands closer to a mainland have higher species richnessThis also occurs when habitats are fragmented for development.