Diversity of Life: Biological Classification

Flashcards covering key concepts from the lecture 'Diversity of Life: Introduction to Biological Classification', including Systematics, Phylogeny, Dichotomous Keys, Cladograms, Convergent Evolution, and Molecular Clocks.

What is the study of the evolution of biological diversity, combining data from fossil records, comparative homologies, cladistics, comparative DNA/RNA sequencing, and molecular clocks?

Systematics

What is the evolutionary history of a species or group of related species, usually organized into a phylogenetic tree?

Phylogeny

How do phylogenetic trees and cladograms arrange organisms?

Based on common ancestry and shared characteristics

What principle guides modern biological classification?

Grouping organisms into categories that represent evolutionary descent

What is the simplest way to identify an organism, consisting of structural features with two alternatives for each feature?

A dichotomous key

What is a key characteristic of a dichotomous key's statements?

They are made up of pairs of statements which have opposing (opposite) descriptions

How did Linnaeus primarily classify organisms, and what problem did this cause for modern taxonomists?

Linnaeus only considered body structures (anatomy); this caused problems because how bodies functioned (physiology) was ignored, leading to misclassifications like dolphins as fish.

What phenomenon occurs when animals live in the same environment and evolve similar body structures with similar purposes?

Convergent Evolution

What is a diagram that shows the evolutionary relationship between organisms, constructed using derived characteristics that proved to be evolutionary advantages?

A Cladogram

How are similarities in the genes of organisms used for classification?

More similarities indicate a closer relationship.

What is the main difference between phylogenetic trees and cladograms regarding branch lengths?

In phylogenetic trees, branch lengths can represent the amount of genetic change or prediction to time, while in cladograms, branch lengths are usually arbitrary.

What tool uses DNA comparison to establish the length of time two species have been evolving independently by counting mutations?

Molecular Clocks

In a cladogram, what does a 'node' represent?

The point where lineages diverge, representing a common ancestor.

Based on the provided amino acid sequences (Human: Lys-Glu-His-Iso, Horse: Arg-Lys-His-Lys, Gorilla: Lys-Glu-His-Lys, Chimpanzee: Lys-Glu-His-Iso, Zebra: Arg-Lys-His-Arg), which animal is most closely related to humans?

Chimpanzee