BIOC61H3 Lecture 10: Lecture 10

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orangeherring876

12 Feb 2011

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The important recognition that some 99% of all the species that have existed on the planet over history have vanished. The number of species today estimated to be alive is 32 to 100 and some put it about 100 million and nobody argues that there is more than that. Wilson is in the biodiversity field and has done work on insect biodiversity in particular but he exaggerates a little. Never before in history have there been that many species alive and this is not surprising. The ongoing forces to diversify would have to bring about larger and larger diversity of species. When life first took root on the planet went from ediacaran from multi-cellular life divergence followed by a bigger explosion in the cambrian (darwin wrote about this). Bacteria organisms have been around much longer from achaean period which is under debate (roughly 3. 5 billion years old). There are other fossils now from s. africa,

Related Questions

What's Your View on Biodiversity? Using an anthropocentric view, the value or importance of biodiversity often is defined using economic measures (e.g., how much money a species is worth). Given such definitions, how much do you spend on species conservation causes or for environmental purposes, including ecotourism, each year? Do you find that this estimate is truly representative of how much you personally value biodiversity? Are there other measures (besides economic ones) that might better estimate the importance of biodiversity to individual citizens? How can one measure the value of biodiversity according to an ecocentric (intrinsic) view?

Q1.14. Which of the following statements about beta diversity is FALSE?

Beta diversity measures how quickly species composition has changed through time.

All else being equal, specialists are likely to be more common where beta diversity is high.

Relatively flat, homogeneous habitats tend to have lower beta diversity.

Beta diversity changes depending on the scale at which you measure it.

Q1.15. Paul Ehrlich and E.O. Wilson offered a number of reasons to protect biodiversity. What were they?

Check all that apply:

Earth cannot "survive" another mass extinction event.

People have an aesthetic and moral obligation to protect Earth's species.

Earth's biodiversity may provide us with important new resources in the future.

Loss of biodiversity may reduce ecosystem services that would be difficult to replace.

Are my answers to the following correct?

True, False, True, C and A,B,D

1. Species accumuation are used to estimate local, or alpha,diversity.

2. The shape of a species accumulation curve depends, in part,on the order in which sampes are processed.

3. Species accumulation curves are not needed when a completecensus is available.

4. Which of the following statements about beta deiversity isFALSE?

a. Beta diversity measures how quickly species compositionchanges across the landscape

b. There are a variety of different ways researchers havemeasured beta diversity

c. Relatively flat, homogeneous habitats tend to have higherbeta diversity

d. Beta diversity changes depending on the scale at which youmeasure it

5. Paul Ehrlich and E.O. Wilson offered a number of reasons toprotect biodiversity. What were they?

a. Earth cannot "survive" antoher mass extinction event

b. People have an aesthetic and moral obligation to protectEarth's species

c. Earth's biodiversity may provide us with important newresources in the future

d. Loss of biodiversity may reduce ecosystem services that wouldbe difficult to replace

False, False, True, True, Sahara dessert, Secular migration andSweetstakes route

6. Immigration rates decline as the size of an islandincrease.

7. Extinction rates decline as the number of species on anisland increases.

8. Extinction rates increase as the size of an islanddecreases.

9. All else being equal, turnover rates are higher on smallislands than on large ones.

10. When we think of islands, we often think of them as landmasses surrounded by water. Ecologists have suggested a muchbroader definition of an island. Which of the following would NOTbe viewed as an island by an ecologist?

a. Mountain top habitats

b. Urban parks

c. Caves

d. Sahara desert

11. Horses originated in North America and then migrates to Asiaand Europe. As they migrates, they evolved over many generationsinto the horse species we see today. This is an example of whichmigration type?

a. Diffusion

b. Jump dispersal

c. Secular migration

12. Horses went extinct in North American and did not returnuntil they were ferried in boats by European settlers (no landmammal can swim on its own across an ocean). From a horse'sperspective, the ocean barrier is best described as...?

a. Corridor

b. Filter

c. Sweepstakes route

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BIOC61H3 Lecture 10: Lecture 10

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