Cell -> tissue -> organ -> organ system -> organism
The snakehead could unreservedly eat little fish and scavangers, so that would evacuate/diminish the predator for zooplankton and phytoplankton. So zooplankton and phytoplankton populace would increment while little fish and scavanger populace would diminish. Presently if little fish and shellfish populace diminishes, their predators would have bring down sustenance, so vast fish pop. would diminish. On the off chance that vast fish pop. diminishes, their predators will have less nourishment thus the number of inhabitants in well evolved creatures will somewhat drop, however not by much, since they can feast upon zooplankton.
So at last, just the phytoplankton populace would increment while everything else diminishes.
That would be false. The Ozone layer is what protects Earth from UV radiation. The Ozone is part of the Stratosphere.
Answer:
Evidence for evolution comes from many different areas of biology:
Anatomy. Species may share similar physical features because the feature was present in a common ancestor (homologous structures).
Molecular biology. DNA and the genetic code reflect the shared ancestry of life. DNA comparisons can show how related species are.
Biogeography. The global distribution of organisms and the unique features of island species reflect evolution and geological change.
Fossils. Fossils document the existence of now-extinct past species that are related to present-day species.
Direct observation. We can directly observe small-scale evolution in organisms with short lifecycles (e.g., pesticide-resistant insects).