One example of a very complex land ecosystem, full of thousands of kinds of living things

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

The leopard frog and the pickerel frog are two closely related species. in areas where their ranges overlap, the frogs will remain separate species if they