EvolutionLesson 1 of 1 in the course Diversity of Life

Phylogeny, Phylogenetic Trees, and Biological Classification

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

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Summary

Biologists use evidence from living and extinct organisms to reconstruct the history of life. This lesson introduces phylogeny and shows how phylogenetic trees represent evolutionary relationships.

A phylogeny is the evolutionary history of a species or group of species, including the relationships among them. Systematics is the study of organisms and their diversity for the purpose of understanding and describing those relationships.

All flashcards

What is a phylogeny?
A phylogeny is the evolutionary history of a species or group of species and the relationships among them.
What is systematics?
Systematics is the study of organisms and their diversity to derive and describe their evolutionary relationships.
What does a branch point represent?
It represents a past common ancestor and the splitting of an ancestral lineage into two or more descendant lineages.
What are sister taxa?
Sister taxa are two lineages that branch from the same immediate branch point and therefore share an immediate common ancestor.
Why can a phylogenetic tree change?
New fossils, morphological observations, or molecular data may provide evidence that supports revising the proposed evolutionary relationships.

Quiz questions

  1. Which sequence lists taxonomic ranks from most inclusive to most specific?Answer: Domain, kingdom, phylum, class.
  2. Which set includes types of evidence scientists may use to infer evolutionary relationships?Answer: Fossils, morphology, and molecular sequences.
  3. Which format follows binomial nomenclature for a species name?Answer: An italicized genus name with a capital followed by a lowercase species name.
  4. Why can appearance alone be misleading when comparing evolutionary relationships?Answer: Similar traits can evolve independently in distantly related lineages.
  5. A tree has branches of different lengths but no time scale. What is the safest interpretation?Answer: The branching order is represented, but branch length does not necessarily indicate elapsed time.

Based on Concepts of Biology by Samantha Fowler, Rebecca Roush, James Wise (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

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