Macroevolution

Overview

Description

Macroevolution is major evolutionary change that occurs above the species level. For example, it includes the evolution of plant reproduction from spores to seeds and the movement of animals from sea to land creatures. There are multiple sources of evidence to support macroevolutionary processes. One important line of evidence is the fossil record, all of the fossilized artifacts taken in the context of their placement within Earth's geological strata. In addition, other lines of evidence, such as molecular evidence, contribute to a robust understanding of the evolution of living organisms, including human beings. As a result, scientists have drawn conclusions from the evidence, as well as hypothesized how evolution caused the transition of organisms from single cells to human beings.

At A Glance

  • Macroevolution involves evolution above the species level; beyond an individual species to the evolution of whole clades or groups over long periods of time.
  • The evolution of life on Earth began with protocells, which evolved over time into the first prokaryotes.
  • Prokaryotes and eukaryotes are the two main groups of living organisms.
  • Patterns in macroevolution include stasis, speciation, lineage character change, and extinction.
  • Fossils record the evolutionary changes in organisms.
  • Ages of fossils may be determined by relative age or radiometric dating of absolute age.
  • Five great mass extinctions dramatically changed the evolution of life on Earth.
  • A phylogeny illustrates the evolution of species and their relationships to other groups.
  • Physical structures may be homologous or analogous in form and function.
  • Species evolve similar structures independently of each other in a process called convergent evolution.
  • Humans evolved from a genus called Australopithecus, which gave rise to all species in the genus Homo.