We began transitioning from our previous unit, Geology, to our new unit, Biology, the study of life. We started off with some key vocabulary and basic definitions:
- environmental factors – anything that can affect an organism’s chance of survival (also known as “limiting factors"); can be divided into biotic (living) factors and abiotic (nonliving) factors.
- species – organisms that can mate (reproduce) with one another to make offspring (babies) that are also able to reproduce! [What truly defines a "species" is a little fuzzy, and we discussed hybrids like ligers and zonkeys, but for our purposes, this definition will do.]
- extinction – the death of a species
- fossil record – the history of living things on Earth as recorded by the fossils they left behind; scientists use them to see how an organism has changed over time
- evolution – "change over time," or "descent with modification;" the central theory of all Life Science; says that all living things on Earth today are modified descendants of earlier living things (ancestors). [Does not necessarily hypothesize about the origin of life.)
- theory – a thoroughly tested explanation of observations, confirmed by multiple lines of evidence; can be used to make predictions. (For example, the Theory of Gravity, Cell Theory, Germ Theory, Atomic Theory. Not just a guess or “idea.” More like a proven hypothesis.)
- hypothesis – an educated guess or prediction
Block D got a chance to read about the Asteroid Impact Theory and discuss the evidence for why the dinosaurs went extinct and mammals afterwards prospered.
They also got to begin a lab simulation activity modeling the fossil record and examining how an organism may have changed, or evolved, over time.