Question

Please give the most simplest, easy to understand, straight to the point explanation. I'm struggling.

- How can molecular data be used to determine evolutionary relatedness? How do mutations play a role in this process? Do mutations occur at a constant rate?

- What type of DNA is used for developing molecular clocks?

- What type of characteristics are used to make phylogenetic trees?

- What is the principle of maximum parsimony and what does it mean for determining phylogenetic relationships?

- What does it mean if a group or species is part of a monophyletic group?

Answer 1

Here i am naming the questions as 1,2,3,4,5

1)Molecular clock can assess the hereditary or genetic molecule differences mainly in theDNA sequence inorder to get the information about the organism's evolutionary relationship. Molecular data will determine the close relatedness by examines how many mutation or the random chnges occured in DNA.They will compare the morphology and genetics of the organism, the More similar the DNA the more close related the species are.

A mutation is a change in the DNA and it is the hereditary material of life. DNA affects the looks of organism, it's behavior, and the physiology. So a change in the DNA cause change in the all aspects of the organism. Mutations are essential to evolution,they are the raw material for genetic variation ,although the mutation rate is constant across the species.

2)A piece of the DNA in which random neutral mutation accumulate at a constant rate is called a molecular clock.The biomolecular data used for such calculations are usually nucleotide sequences for DNA and or amino acids sequences for protein. Nowadays mitochondrial DNA should accelerate rates of evolution in certain animals but nuclear DNA not.

3)Phylogenetic tree,it's a branching diagram or tree showing the evolutionary relationship among various species. The are constructed using various data off organisms from the studies. The data used are, homologous traits, analogous trait, physical characters, generic characters and molecular evidences.

4)Maximum parsimony means the optimal tree will minimise the amount of homoplady ie,...convergent evolution, divergent evolution, and evolutionary reversals. Or in other words the shortest possible tree that explains the data is considered best. The principle is atkin to Occams razir(law of parsimony),this states that "all else being equal",ie the simplest hypothesis that explain the data should be selected.

We use the principle in finding phylogenetic relationship or drawing phylogenetic trees. When we draw a phylogenetic tree we must first determine which species in a group are closely related to each other. We can compare the DNA or physical character of the do species in group and look for differences. Here we can apply the principle ie,...the tree that require fewest evolutionary changes is the one you should assume is correct.

5)Monophyletic group is the group of organisms that consist of all the descendants of a common ancestor. If a group or species is a part of a monophyletic group it means that they have the most recent common ancestor for that species or group.