There is an island in the middle of a large river that houses a large population of ants. damming of the river causes the island to flood and only the highest points of the island are now above water. the ants cannot swim, so are now in multiple isolated populations. which of the following best describes this event?
a. isolation by dispersal
b. isolation by vicariance
c. a form of sympatric speciation
d. only a rare development of polyploidy could lead to speciation in this case
e. speciation will not occur in this case because of gene flow

The energy needs of a human population are not affected by

The diagram below represents a marine food web and a process that can harm the human population. each circle represents an organism and the smaller dots inside them represent a toxic substance. what is being represented and how does it harm the population? the diagram represents biological half-life, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents biomagnification, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents the process by which different organisms prey upon each other; this can impact the human population by reducing the number of organisms that do not contain the toxin. the diagram represents the way that toxins are metabolized by living organisms, with those at greater trophic levels able to metabolize more efficiently than those at lower levels. this means that those at higher tropic levels are safer for humans to consume compared to the organisms at lower trophic levels.

Spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?