Bio Graded Quiz 1 Active Recall

pray.

5 Characteristics of Life

Reproduction, Evolution, Process Information, Require Energy, Made of Cells

Mass Extinction

when extinction rates are significantly greater than the background rate (not all life dies, that’d be a total extinction. remaining life survives + adapts)

How many mass extinction have we had + what caused them?

5, drastic changes in global environment/climate.

What is the great oxygenation event?

Cyanobacteria (single-celled organism) produce oxygen, atmosphere shifts from being mainly CO2 to O2. This leads to ozone layer and allows many organisms to move to land (and eventually allows for multicellular?).

Timeline of Life

4.5 bya = Earth is created

3.8 bya = First single celled organisms appear

2.3 bya = Great oxygenation

0.8 = First multicellular organisms appear

0.55 = Cambrian explosion (hundreds of nautilus in my house bro)

200,000 ya = First modern humans

Typological Thinking

Plato: belief that all life is created perfect by god and doesn’t change, variation within a species is trivial, and that species are not related.

Scale of Nature

Aristotle (Plato’s Student — addon to typological thinking): Organisms are arranged from simple to complex.

Lamarck’s Theory

Species ARE related/variation IS relevant, species DO evolve but evolution occurs linearly from simple to complex (but is still the end of typological thinking).

Evidence for Species Changing Over Time

Fossil Evidence (extinct species + transitional forms imply change), Age of Earth (4.5 billion years (determined by radiometric dating) is enough time for large changes to occur).

Evidence for Common Ancestry

Artificial Selection, Biogeography/Law of Succession, Homologies

Biogeography

Study of where organisms live.

Law of Succession

Two species living in identical climates but different places will more closely resemble the fossils found in their respective places than each other (opposite of what typological thinking implies).

Structural Homology

Similarities in structure/anatomy (ex. all organisms having cells is a structural homology).

Genetic Homology

Similarities in DNA/RNA composition due to common ancestry.

Developmental Homology

Similarities in embryonic shape/morphology due to common ancestor.

Vestigial Trait

Structure with little-to-no function, but a similar structure has a function in either a relative or an ancestor.

Evolution Definition 1

Descent with modification

Species

A population of interbreeding individuals that can produce viable offspring.

Homology

Structural/molecular similarities due to common ancestor.

Artificial Selection

Humans/relatively direct human actions only allowing those w/ particular traits to reproduce

Taxonomy

Field of describing/naming/classifying organisms.

Phylogeny

Study of evolutionary relationships.

Caveats for intermediate forms/fossils

Fossilization is rare, fossils are easily destroy, evolution is NOT progressing towards perfection.

Monophyletic/Clade

A grouping w/ a single common ancestor and ALL descendants.

Non-monophyletic

Lacking a common ancestor OR missing descendants.

Synapomorphy

Trait derived from most recent common ancestor that unites multiple taxa and distinguishes them from other taxa.

Homoplasy/Analogous Trait/Analogy

Similar trait that develops in multiple taxa but NOT due to shared ancestry.

Divergent Evolution

Taxa w/ common ancestor develop different traits over time.

Convergent Evolution

Unrelated taxa develop the same traits due to similar conditions NOT because they have a common ancestor.

Darwin + Wallace’s Theory of Evolution (Descent w/ Modification)

Species change over time, are related by common ancestors, and are changed via. natural selection (so surprise variation is important)