Login

Join for Free!
117100 members


Speciation and Evolution

Discussion of everything related to the Theory of Evolution.

Moderator: BioTeam

Speciation and Evolution

Postby 1357 » Mon Nov 25, 2013 4:01 am

Suppose some natural disaster occurs and a species of finch is forced to relocate from its original island where it dined on cactus flowers to an adjacent island with many fewer cacti but an overabundance of orchids. What would be the immediate consequences to the species in the first month of the change?

A. the species would change its eating habits to feed on orchids.

B. all of the members of the species would make do with the existing cacti on their new island.

C. the entire species would go extinct.

D. most of the members of the species would die but some would survive.


Study the image of the fossil shown below. How might a scientist use this fossil to learn more about the history of life on Earth?

connexus dot com/content/media/917517-4162013-72829-PM-1012149111.jpg

A. to compare structures in the fossil with homologous structures in other vertebrates.

B. to look for vestigial structures in the fossil and compare them with functioning structures in living organisms.

C. to examine the fossil for evidence of the stages of embryological development of the animal to compare to development of living animals.

D. to determine the mineral content of the fossil and compare it with that of other fossils.
1357
Garter
Garter
 
Posts: 7
Joined: Mon Nov 25, 2013 3:57 am

Postby 1357 » Mon Nov 25, 2013 4:15 am

For the first one, I think it is D, because they can't adapt so soon to eating orchids. For the second one, I can't decide between A and B. A is good for finding relationships between two organisms, but B concerns more of Earth's history
1357
Garter
Garter
 
Posts: 7
Joined: Mon Nov 25, 2013 3:57 am

Postby JackBean » Mon Nov 25, 2013 12:39 pm

1) D looks the best to me
2) I'm deciding between A and B as well. If that's only-one-right-answer question, I'd go with A, because B says to compare vestigial structures in fossil and compare with functional structures in living organisms. However, it should be rather the other way, first (in the past) you have functional structure which loses its function during time and becomes vestigial. But that's only my guess. One can still find functional structures in nowadays animals homologous with vestigial structures from past organisms, I'd say.
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5667
Joined: Mon Sep 14, 2009 7:12 pm


Postby 1357 » Mon Nov 25, 2013 6:31 pm

Yes, I think it is A, too. If vestigial structures are compared with functioning structures today, it does not make sense because the two would be different.
1357
Garter
Garter
 
Posts: 7
Joined: Mon Nov 25, 2013 3:57 am

Postby Darby » Tue Nov 26, 2013 1:45 pm

The first question, there's no way to tell between C and D - a month is enough time to starve all of the birds, and why would we be sure that ANY individuals could make the shift from cactus to orchid at any point in time?

There are two possible answers to the second one as well, since the "fossil" is an entire block of rock...
Darby
Viper
Viper
 
Posts: 1262
Joined: Thu Mar 02, 2006 5:29 pm
Location: New York, USA

Postby 1357 » Tue Nov 26, 2013 10:14 pm

I agree; both C and D are possible for the first one and we can't exactly tell which one. However, there are some cacti on the new island from which the birds could try to survive. Perhaps some would survive from the cacti on the adjacent island.
1357
Garter
Garter
 
Posts: 7
Joined: Mon Nov 25, 2013 3:57 am

Postby JackBean » Tue Feb 25, 2014 9:46 am

Exactly, there are still some cacti on the new island, so there's no reason why the strongest (those who can fight away the other birds) shouldn't survive.
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5667
Joined: Mon Sep 14, 2009 7:12 pm


Return to Evolution

Who is online

Users browsing this forum: No registered users and 4 guests

cron