Biodiversity and Phylogeny Practice Flashcards

A set of vocabulary flashcards covering the geological timeline, biodiversity organization, and phylogenetic principles based on the lecture notes.

Biodiversity

The variety of life, generated by evolution via speciation, and described through genetic variation, species richness, community composition, and ecosystem diversity.

Earth's Age

According to the lecture, the Earth is approximately $4.6$ billion years old (byo).

Evolutionary Duration

Biodiversity has been evolving on Earth for approximately $3.8$ billion years.

Stratigraphy

The study of sedimentary rock layers which form over time, where younger layers of rock are typically found on the surface.

Carbon-14 ($14C$) Half-life

A radioisotope used for dating with a half-life of $5,700$ years and a useful dating range of $100-60,000$ years.

Potassium-40 ($40K$) Half-life

A radioisotope used for dating with a half-life of $1.3$ billion years and a useful dating range of $10\text{ million}-4.5\text{ billion}$ years.

Cyanobacteria

The first organisms to perform oxygenic photosynthesis, releasing massive amounts of oxygen into the atmosphere and oceans.

Stromatolites

Layered sedimentary formations created by biofilms of microorganisms, primarily cyanobacteria, trapping and binding sediment over time.

Great Oxidation Event

The rise of atmospheric oxygen that allowed for the evolution of aerobic respiration, which is more energy-efficient than anaerobic methods.

Precambrian Era

The geological era spanning from $4.6$ bya to $542$ mya, dominated by small aquatic life and the origin of photosynthesis and eukaryotes.

Paleozoic Era

The geological era spanning from $542-251$ mya, consisting of six periods (Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian) and characterized by marine radiations and the transition to land.

Mesozoic Era

The geological era spanning from $251-65$ mya, consisting of the Triassic, Jurassic, and Cretaceous periods; known for reptile radiations and the origin of mammals.

Cenozoic Era

The geological era spanning from $65$ mya to the present, featuring the dominance of flowering plants, mammalian radiations, and the evolution of $\text{Homo}$.

Taxonomy

The discipline of ranking (grouping) and naming organisms.

Taxonomic Hierarchy

The nested sequence of groups: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Binomial nomenclature

The system of naming organisms (e.g., $\text{Peromyscus leucopus}$) developed by Linnaeus.

Phylogeny

A diagram or portrayal of the evolutionary relationships among organisms based on common ancestry.

Node

A point on a phylogenetic tree where an ancestral lineage divides into two descendant lineages.

Monophyletic group (clade)

A group of organisms that consists of a common ancestor and all of its descendants.

Homoplasy

Features that arise due to convergent evolution (like wings in bats and birds) or evolutionary reversal (like the loss of mitochondria in protists) rather than shared ancestry.

Synapomorphy

A derived trait that is shared between taxa and used to construct phylogenies.

Parsimony

The principle used in constructing phylogenies where the simplest explanation possible (minimizing the number of evolutionary changes) is preferred.