In a controlled experiment, an independent variable (the cause) is systematically manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled. The researcher can operationalize (i.e. define) the variables being studied so they can be objectivity measured.
The correct answer is it decreases genetic diversity only by reducing population size.
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The great explanation for this is a bottleneck effect, which is an extreme example of genetic drift. The bottleneck effect occurs when the size of a population is reduced due to a catastrophe. When it happens, only a small, random number of individuals survive the event and pass through the bottleneck. Thus, the genetic composition of the random survivors is now the genetic composition of the entire population which means that the genetic diversity is reduced.</span>
Answer:
The answer is C. An increase in competition for sunlight and space among plants
Answer: C. 30 - 50 million years ago
Explanation:
Fossils found in layer Y formed 30 million years ago according to the graph above. Similarly, fossils found in layer Z formed 50 million years ago.
If a fossil (fern fossil) is found between layer Y and layer Z, it means that it formed between the years that the fossils in layers Y and Z formed which is 30 - 50 million years ago.
Answer:
<u><em>Hey There the correct answer would be is D. Individual organisms</em></u>
hope it helps!