BIOL 230 Lecture Notes - Lecture 7: Ellesmere Island, Adaptive Radiation, Speciation

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silverjellyfish556

4 Jan 2017

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Tropics: high biodiversity threatened by deforestation and economic inequality. Poles: low species richness limits resilience to climate change. Species richness number of species in an area. Overall species richness pattern highest in the tropics, lowest near the poles, intermediate in between. Stable climate = more time to evolve/speciation occurs. Does not influence immigration. (cid:894)species do(cid:374)"t choose to go there cause it"s war(cid:373)(cid:895) Immigration low, isolated more than 88mil years ago. 90% are endemic (found no where else on earth) Higher latitudes = more disturbances (increasing extinction rates) Tropical areas more climatically stable over geological time, allowing species to accumulate (even if speciation rates the same) Species (and taxonomic levels) tend to originate in the tropics and disperse to temperate and polar areas. Species tend to go extinct in temperate and polar regions because of frequent or extreme changes in climate.

Related Questions

Today you will be using an online visualization tool that illustrates the vulnerability to extinction of different groups of (mostly) terrestrial organisms. Spend some time looking through the website at projects.propublica.org/extinctions.

What group of organisms (mammals, reptiles, amphibians, or birds) hasâ¦

â¦the largest percentage of at-risk species? Whatâs the percentage?

â¦the smallest percentage? Whatâs the percentage?

Select any one family from the mammal, reptile, amphibian, or bird groups that has at least 40% of its species at risk for extinction (that is, the family grouping is colored red) and do some Internet research to identify some major mechanisms that have placed that members of that family at risk (e.g., climate change, habitat destruction, pollution).

Family:

Reasons for at-risk status:

Time for another website. You can google âGuardian endangered species mapâ â the site you want should be one of the top two search results â or you can type in the following: http://www.theguardian.com/environment/interactive/2012/sep/03/extinct-and-endangered-species-interactive. This map shows where species have already gone extinct and where the critically endangered species of today are located.

What country has had the largest number of extinctions since 1500? Within your group, talk about why this might be.

Now go to the âCritically endangered speciesâ view of the map (upper right corner). Where are the spots with high concentrations of critically endangered species? For your answer, you can either list specific countries, continents, sub-continental regions (e.g., southeast Asia, northern Asia), or climatic zones (e.g., tropics, subtropics). Your choice.

Now go to the âIn numbersâ part of the map (upper right corner). By clicking on the circles, you can see which groups of organisms are most threatened in different regions of the planet.

After clicking on all of the regions on the map, can you make generalizations about what group(s) of organisms is/are most threatened globally? (For the purposes of this question, ignore the âplants, insects, and otherâ catchall category and focus on the other groups.)

Are there important regional differences that stood out to you?

rubyeel26

The massive Deep Horizon oil spill of 2010 released enough crudeoil into the Gulf of Mexico to fill an entire swimming pool about 7thousand times.

How do we know the damage possibly caused by such a disaster? Wecould always plan an experiment..... If you worked for the Dept. ofFish and Game in the Gulf States, maybe you would...

You could take a part of the sea floor very nearby the site of thespill, say an area exactly 100 square meters, and count the numberof different species that you find. This would be a measure of"Biodiversity", which is generally a good indicator of ecosystemhealth - in general, the more Biodiversity, the healthier theecosystem.

Then you could sample an area of the seafloor exactly the samesize, but further away (say 1 km) from the spill site, and countthe number of species in that site. And then continue sampling thesame size area at 1 km intervals, until you reach an area manykilometers away from the spill site where you know the area wasrelatively undisturbed by the spill.

If you run this experiment,

1) What is the independent variable?
2) What is the dependent variable?
3) What is one very obvious control variable?
4) Why would you want to sample for biodiversity in each of thesites at the same time of day?

And....
5) What is a valid hypothesis that you could have for thisexperiment?

lemonllama817

PLEASE FILL IN THE BLANK

PART1

Investigators want to study the effects of a new growth hormone on mice. To do this, they select a population of mice that are ____________ .

One subset of the group, Group A, receives the newly developed growth hormone. This group is called a ____________ .

One subset of the group, Group C, receives no growth hormones of any kind. This group is called the ____________ .

One subset of the group, Group B, receives an already proven growth hormone. This group is called a ____________ .

Once results are analyzed, the findings show that Group A experiences a 20% increase in growth, Group B experiences a 10% increase in growth, and Group C experiences no increase in growth. These results show that the new growth hormone had ____________ on growth and works ____________ the old growth hormone.

CHOICE OF WORDS:

genetically diverse

test group

better than

control group

gentically identical

no differently than

a positive effect

a negative effect

part2

Defined as variation of life on Earth, ____________ is the number and relative abundance of different ____________ .

It is estimated that there are as many as ____________ species in the world, though as few as ____________ of these species have actually been identified.

As the human population grows and demands more resources, ____________ is threatened.

Human activities contribute to ____________ , especially in the world's coral reefs and tropical rain forests. As a result, some organisms face ____________ , or the death of their species.

Human activity has ____________ the rate of ____________ by a factor of 100 to even 1000, meaning that every day as many as 400 species face extinction.

Humans also face ____________ consequences in that we are dependent on the ecosystems we are destroying for everything from food to raw materials.

Choice of words:

decreased

habitat loss

species

2 million

positive

ecosystems

biodiversity

extinction

negative

increase

1.5 million

BIOL 230 Lecture Notes - Lecture 7: Ellesmere Island, Adaptive Radiation, Speciation

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