A genetic change in a population of organisms is ________.
are random, meaning they are unrelated to how useful or harmful they might be to the organism in which they occur.
For natural selection to be operating in a population, one of the things that must be present is a particular trait that must be capable of being passed on from parents to offspring. Another word for this is:
The consistent accumulation of mutations that creates differences in the DNA sequences of two diverging groups of organisms is referred to as:
a "molecular clock."
→ Great job. The molecular clock "ticks" over time, and the longer two species have been evolving on their own, the greater the number of changes in amino acid sequences or "ticks of the clock."
All northern elephant seals come from a very small genetic pool. This is because in the 1890s a large number of them were very quickly killed until their population size was reduced to only about 20 individuals. Though their population has since increased to over 30,000 individuals, all their genes have come from those 20 individuals. Which of the following population genetic concepts does this example represent?
the bottleneck effect
Exceptionally large babies increase a mother's mortality risk when giving birth, and exceptionally small babies tend to die at birth or shortly afterward. For these reasons, birth weight in human babies is generally: