"Multiple, recurring origins of aposematism and diet specialization in poison frogs" by Santos

I have some question about the article "Multiple, recurring origins of aposematism and diet specialization in poison frogs" by Santos et al. 1. Why is aposematism difficult to explain from an evolutionary point of view? 2. Which hypothesis regarding the evolution of aposematism in dendrobatid frogs are the authors testing? 3. Briefly explain the approach they are using. (this paper is full of technical details, just describe the "big picture") 4. Which conclusion did the author reach about the evolution of aposematism in this group? 5. How are the evolution of aposematism and the evolution of diet specialization related to each other?

Solving Practice Problem

We are given the following five sequence: Taxon 1, Taxon 2, Taxon 3, Taxon 4, Taxon 5 TGCCAA, GGACAA, TGTCAA, TGTCAT, GGACAT a) In general, how many unrooted trees are there relation five taxa? b) Draw the following two trees. the first one has taxa 2 and 5 as sister taxa and taxa 1 and 3 as sister taxa. the second one has taxa 2 and 5 as sister taxa and taxa 3 and 4 as sister taxa. c) Determine the minimum number of mutations that would be required to explain the observed sequences based on each of the two trees that you drew in part (b). d) Based on the principle of parsimony, which of these trees would you argue bestfits the data?

Monophyletic Plants

Could you please tell me WHY green algae and land plants are considered to be monophyletic? I can't seem to find specific info in my text. Thanks!

Problems of Land Plants, Telome Theory, and Rhynia

There are actually three questions here, all dealing with Rhynia (Rhynia is known by two names, the diploid life cycle "Rhynia major", and the haploid life cycle "Rhynia gwynne-vaughanii"). I thought it would be a good idea to put these 3 questions together because they all deal with the same general ideas. 1) HOW HAS THE FERN IMPROVED OVER RHYNIA RELATIVE TO THE WATER-RELATED PROBLEMS ASSOCIATED WITH MOVING TO THE LAND? 2) BRIEFLY DISCUSS HOW RHYNIA SOLVED 7 OF THE FOLLOWING PROBLEMS THAT LAND PLANTS FACE BY LIVING ON LAND. a. Get water - accomplished by roots. Hardest part of move from water to land habitat was that organisms had to live in a medium that has more than on... click for more

Siphonogamy and the Seed. Which one came first?

-- Define and briefly discuss both siphonogamy and the seed. -- Which do you think came first? I have a good start on the definitions, but please reword or (briefly) add to them to make them complete: A seed is: a fertilized, integumented, (Sterile covering/coating. Provided by diploid parent) undehiscing (non-splitting. Does not split open for sperm) megasporangium. (Place where meiosis takes place to produce female eggs). Siphonogamy: the process of getting a sperm to an egg without water