Sage-Tips

What is different about the DNA sequence of different species?

We all come from a common ancestor. But the reason for the difference between and within species is the amount of variation that has been accumulated within evolutionary time. The more variations, more different you are, and so two different species.

What uses the regular rate of the change in DNA to determine when two species had a common ancestor?

The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleotide sequences for DNA, RNA, or amino acid sequences for proteins.

Which species is most closely related to the clade formed by species A and species B?

Which species is most closely related to the clade formed by species A and species B? Species C, D, and E are equally closely related to the clade. In its application to phylogenetics, parsimony is a method that… Not counting the root, how many nodes are in a phylogenetic tree with five species?

Do Different species have different DNA sequences?

Genome analysis suggests that the two species are swapping genes at a surprising rate. But each species has genome segments unique to its own kind, which seem to persist despite the mixing of the rest of the genome.

What is the relationship between the difference in the DNA of two species and the time of divergence of their evolutionary history?

As species differentiated over evolutionary time, the DNA sequences in their genes acquired slight changes. According to evolutionary theory, these changes accumulate over time: species that diverged from each other long ago have more differences in their DNA than species that diverged recently.

How do molecular and fossil age estimates differ?

While the molecular clock can be used to extend the time estimates from fossil species to lineages not represented in the fossil record, fossils are the only source of information concerning absolute (geological) times in molecular dating analysis.

Which terminal taxon is B more closely related to A or C?

In that figure, Taxon B and Taxon C are more closely related to one another that either is to Taxon A. We know this because Taxon B and Taxon C share a shallower node (the blue node) than then node that either shares with Taxon A (the yellow node).

What does A B C and D mean in DNA sequencing?

The sequences of living species are labeled A, B, C, and D. Changes in nucleotide sequence are indicated for each branch in the tree. For example, T2 → A means that the second base, a T, was changed to an A. The first base (G) in sequences B, C, and D is a shared primitive character.

Is there genetic diversity within a species?

Of course there is genetic diversity within a species that renders everything a little bit more complicated. For example, some of you have blue eyes while others have brown eyes (assuming there is variation for eye color among your students), this is due to the fact that the DNA sequence within each of you is a little different.

Is no extant species the ancestor of another species?

Explain that no extant species is the ancestor of another species as the ancestors are the nodes. You can get a short introduction to phylogenetic trees here on Biology.SE or here on Understanding Evolution.