Why do functionally "anomalous" characters (e.g., the whale's non-functional hip and leg bones) support Darwin's inferred evolutionary relationships between certain groups (e.g., the whales and other land mammals)?
Darwin suggested that all mammals have a COMMON ANCESTOR and that when the species DIVERGED to form new species, DESCENT WITH MODIFICATION occurred. The whale's non-functional hip and leg bones, left over from the COMMON ANCESTORS ALL MAMMALS SHARE, did n
What are possible reasons the CCR5-?32 mutation is in relatively high frequency in N Europe?
The CCR5-?32 mutation is likely found in relatively high frequency in N Europe because of STARTING FREQUENCY. If populations in N Europe HAPPENED TO HAVE the HIV resistance gene in a higher frequency than in Africa, when the most recent HIV epidemic began
In evolutionary terms, why are drug cocktails used to treat HIV?
HIV drug cocktails are an effective way to raise the number of mutations required for resistance. When two or more drugs are administered to a patient at once, it's LIKELY THAT A MUTATION THAT RENDERS A VIRION RESISTANT TO ONE DRUG DOES NOT RENDER IT RESI
We used Figure 6.14 as an example of how the frequency of an allele (in fruit flies) does not change in unselected (control) populations but does change in response to selection. However, look again at the unselected control lines in Figure 6.14. The freq
These small changes are likely due to genetic drift caused by chance events. The easiest way to reduce this effect is to use a larger population size. This topic is discussed further in Chapter 7.
selection prevents pop from accumulating mutations outside of the range that's most adaptive
if environment isn't changing, little evolutionary change
quick change in environment = quick evolution
relatively stable environment; little to no change
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