Chapter 26 Flashcards
What is homoplasy?
A character shared by a set of species but not present in their common ancestor.
Ex: the evolution of the eye which has originated independently in many different species.
What is Plesiomorphy?
The ancestral traits (NOT helpful in classifying)
What is a polyphyletic group?
Usually comes because of convergent evolution; they look similar but are of completely separate ancestors.
Ex: Cetaceans (Dolphins) have same ancestor with hippos but are included in same group as seals, which share common ancestor with bears.
Why arent autapomorphies helpful?
Wolf, Siberian husky, coyote, grey fox all belong to the same species. A Chihuahua looks VERY different from the four dogs but they belong to the same species as the husky.
What are taxa?
Taxa are the names (Panthera pardus, Chordata, Animalia etc.)
What does a Monophyletic group mean?
Monophyletic group is a group of species that all descend from a common ancestor.
- They dont include species outside of common ancestor or exclude species with common ancestor.
What is Autapomorphy?
It is a character in one species (It is not helpful classifying)
What group do fish exist in?
They exist in a paraphyletic group.
What is molecular clock?
It is looking at mutation rates and gene similarities to see how evolutionary patterns are formed.
What is parsimony?
Parsimony or a Parsimonious tree is on that is accurate with the least amount of steps.
What does HIV do?
As your immune system tries to make things to fight off HIV, HIV will change and mutate.
- Information order usually goes DNA to RNA to Proteins
- HIV creates a reverse transcriptase, this enzyme goes against the information order. HIV makes RNA and changes to DNA this creates a chance to mutate the DNA.
What is vertical gene transfer?
it is the transfer of DNA by sexual transmission.
What is the difference between snakes and lizards?
Snakes: Dont have eyelids, no legs, 1 lung, and can dislocate jaws.
Lizards: Have eyelids, usually have legs, 2 lungs, no jaw dislocation
What are some of the problems with common and scientific names?
the differences between an Australian marsupial “mole” and a North American eutherian mole. Although they have some similar characteristics the Australian marsupial “mole” is actually more closely related to kangaroos and koalas than moles.
What can you figure out with a molecular clock?
You can find the estimated divergence times if you know the mutation rate and the genetic similarity between taxa.
