Common Ancestry, Evidence & Branching Trees — Drills · Grade 7 Science

Chapter: Evolution, Evidence & Life History

What these drills covers

By the end of Common Ancestry, Evidence & Branching Trees you should be able to:

4 questions, multiple choice and written answer, each with a worked explanation.

Vocabulary used: common ancestor, homologous structure, vestigial structure, phylogenetic tree, node.

Problem 1

Which determines the represented relationship?
  1. Shared branching nodes
  2. Alphabetical tip order
  3. The prettiest color
  4. Every tip’s horizontal spacing
Answer and explanation

Shared branching nodes

Topology and shared nodes represent relationships; display choices need a stated meaning.

Problem 2

Why combine fossils, anatomy, and genetic evidence?
Answer and explanation

Different observations can test related aspects of a relationship hypothesis. Agreement strengthens it while limitations or contradictions guide further investigation.

Problem 3

Does the same function alone prove close ancestry?
Answer and explanation

No. Similar functions can arise through different histories; structural and other evidence must be compared.

Problem 4

Why is one short sequence an incomplete relationship test?
Answer and explanation

It may not represent the whole history and can be affected by sampling and different rates; additional regions and other evidence help.

Browse all courses