Where was darwin when he noted that there could be possible links between distinct but similar species?

Which of the following is one of the four conditions necessary for natural selection to occur in a population? fewer organisms are born than the habitat can support mutation does not occur organisms have identical characteristics variation is inherited

The eruption of a nearby volcano causes a prairie ecosystem to receive a lot less sunlight. which of these is most likely effect on the ecosystem?

Which anatomical plane is the only one that could not show both the sternal region and vertebral region