| Term | Definition | | Logical Fallacies | The use of faulty reasoning (e.g., ad hominem attacks on scientists, appealing to emotion) to dismiss scientific findings. |
| Machine learning (ML) | Machine learning is a subfield of artificial intelligence. Instead of computer scientists having to explicitly program an app to do something, they develop algorithms that let it analyze massive datasets, learn from that data, and then make decisions based on it. |
| Manufactured Doubt | A strategy to make a consensus issue (like tobacco safety or climate change) appear heavily disputed, even when evidence is strong. |
| Median | In a set of numbers or data points, the median is the number that falls exactly in the middle: half the numbers in a data set are higher and half are lower than the median. |
| Methane (CH4) | A hydrocarbon that is a greenhouse gas with a global warming potential most recently estimated at 25 times that of carbon dioxide (CO2). Methane is produced through anaerobic (without oxygen) decomposition of waste in landfills, animal digestion, decomposition of animal wastes, production and distribution of natural gas and petroleum, coal production, and incomplete fossil fuel combustion. |
| Misinformation | False information shared without malicious intent. The person sharing it often believes it to be true. |
| Model | A model is a tool that helps researchers predict how a system is likely to behave. In scientific use, a model can be used to support a hypothesis if it generates the expected behavior. |
| Model Organism | A species that has been widely studied, usually because it is easy to maintain and breed in a laboratory. Scientific discoveries in model organisms can often tell us a lot about the workings of many other organisms, too. A few examples of common model organisms are fruit flies, mice, zebrafish, and the bacteria E. coli. |
| MRNA | Messenger RNA (mRNA) is a type of single-stranded RNA molecule that plays a fundamental role in biology by carrying instructions from DNA to the ribosomes, where proteins are synthesized. |
| Mutagenesis | A process by which an organism is genetically changed, resulting in a mutation, which is a change in the DNA sequence of a gene. It may occur naturally, for example, due to natural exposure to ultraviolet (UV) light or chemicals; or it can happen deliberately for the purpose of increasing genetic variation of a species. |
