Please answer these questions on a separate sheet(s) of paper, and please type.
ID: 3164807 • Letter: P
Question
Please answer these questions on a separate sheet(s) of paper, and please type. It is imperative that no part of your answer be copied directly from an online source, or from another student, either in this class or from a previous year. Some of these responses require you to cite sources (hint, we ask you to research). Chegg.com and Yahoo answers are not appropriate sources. This problem set is due by safe assign, the due date being listed on the syllabus, and is very firm.
(two points) A researcher is excavating a fossil bed from a Devonian reef, now fossilized in Pennsylvania. She encounters many species that are new to science.
a) Which species concept would be most expedient and effective, in the process of collecting, naming, and describing what she finds?
b) Go online and research. Give at least three examples of actual species that were present in the Devonian period. What is the point, if there IS any point, to naming and describing species that went extinct millions of years ago?
c) Research reefs. Give some ideas about why reef communities, in times during the history of the Earth when they existed, have such high diversity? What happened to the Devonian reefs?
d) Research and describe threats to contemporary coral reef systems. List, and describe, the major threats to these systems resulting from climate change, human disturbance, ocean acidification, and other factors.
2. (two points) A researcher is studying the mating calls of a widespread species of syrphid fly. She discovers that males differ greatly in their banding patterns, but females are essentially identical. In laboratory crosses, females do not discriminate among males with different banding patterns, BUT, when they mate with males that do not have a banding pattern typical of the area they came from, these crosses produce eggs that do not hatch.
Are these flies a single species, or perhaps a species complex? Is there an isolation mechanism? Explain?
Go online and research. Give at least two examples of species complexes composed of morphologically similar microspecies or cryptic species.
What is a syrphid fly? Research a few species and describe the ecological niches they occupy.
3. (two points) A population of humans, isolated for centuries on an island in the Indian Ocean, exhibits the following phenotypes for the M N blood group locus.
330 M
375 MN
295 N
LM and LN are two codominant alleles at this locus. LMLM alleles give type M blood. LMLN individuals are heterozygous. LNLN individuals are type N blood.
Using the Hardy-Weinberg equilibrium, calculate the expected frequencies of these blood types. Do a chisquare test of goodness of fit to compare observed and expected values. Is this population in Hardy-Weinberg equilibrium?
What might be going on here? What factors might cause a distribution of genotypes like this?
Go online and research the MN blood type system. What is its molecular mechanism? Name at least two human populations with unusual MN allele frequencies.
4.(two points) Reserarch a study of natural selection in the wild or in the laboratory, and in a few paragraphs, describe the aims of the study, the results of the data, and the implications of the results.
5. (two points) Go to the following link and read the paper.
http://www.nature.com/articles/srep00757
Write a two paragraph summary of what you learned from reading it.
Explanation / Answer
1a.The Morpho species concept will be the most effective because sceintist by comparing difference in the size,shape,colour and structure of one organism with other organism can use evolutionary independent linage.Biolgically species cannot be applied here because it is based on population who interbreed.The phylogenetic concept cannot be used because DNA cannot be applied.
2.Dunkleosteus :Arthrodire placoderm fish.This fish has existed during the late Devonian period which is 352-382 MYA
Placodermi-armored fish.It has lived from the Silurian to the end of Devonian period.
Spiriferida-It is known for it's long hinge line.
The name of the species is very important because we will come to know where the species once lived,the environmental condition and also the ancestors of the animals.
c.Coral reefs have first appeared in the Cambrian period,542million years ago.They have the highest biodiversity compared to any ecosystem on the planet.They provide food and shelter to 25%of marine life and occupies one percent of ocean floor
d.The threats to contemporary coral reefs are coral bleaching,ocean acidification,overfishing, pollution and mining.
Ocean acidification is associated with climate change and occurs when atmospheric CO2 rises and the oceans absorb it.
When the algae zooxanthellae leaves,the corals at a risk of dying since these algae provide 80% if the energy.Ths is called coral bleaching.
Corals can't take toxins in the environment and because of this they die due yo pollution.
2.a.These species appear to be a species complex meaning that the species are similar to each other in appearance.One explanation of the unviable eggs is ,assuming my first assumption of species complex is correct,interbreeding
barriers have been put into effect.Postzygotic isolation is a barrier which prevents breeding and causes the unviable eggs.
b.An example of cryptic species is the African elephant,two barred flasher butterfly.
c.Syrphidflies also called as the flower flies are seen nectaring at flowers.The adults of these species feed on nectar and pollen while larva eat wide range of food.This species is common on Pacific Northwest orchard.