• Skip to primary navigation
  • Skip to main content
  • Skip to footer
  • About
  • Image & Use Policy
  • Translations
  • Glossary

SUPPORT UE

  • Email
  • Facebook
  • Twitter

UC MUSEUM OF PALEONTOLOGY

UC Berkeley logoUC Berkeley

Understanding Evolution

Understanding Evolution

Your one-stop source for information on evolution

Understanding Evolution

  • Home
  • Evolution 101
    • An introduction to evolution: what is evolution and how does it work?
      • 1_historyoflife_menu_iconThe history of life: looking at the patterns – Change over time and shared ancestors
      • 2_mechanisms_menu_iconMechanisms: the processes of evolution – Selection, mutation, migration, and more
      • 3_microevo_menu_iconMicroevolution – Evolution within a population
      • 4_speciation_menu_iconSpeciation – How new species arise
      • 5_macroevo_menu_iconMacroevolution – Evolution above the species level
      • 6_bigissues_menu_iconThe big issues – Pacing, diversity, complexity, and trends
  • Teach Evolution
    • Lessons and teaching tools
      • Teaching Resources
      • Image Library
      • Using research profiles with students
      • Active-learning slides for instruction
      • Using Evo in the News with students
      • Guide to Evo 101 and Digging Data
    • Conceptual framework
      • Alignment with the Next Generation Science Standards
      • teach-evo-menu-icon
    • Teaching guides
      • K-2 teaching guide
      • 3-5 teaching guide
      • 6-8 teaching guide
      • 9-12 teaching guide
      • Undergraduate teaching guide

    • Misconceptions about evolution

    • Dealing with objections to evolution
      • Information on controversies in the public arena relating to evolution
  • Learn Evolution

Home → Types of developmental change
  • ES en Español

Types of developmental change

Developmental changes have likely been involved in important morphological changes — like the evolution of novel and complex structures.

Here are a few of the sorts of developmental changes that may have been important:

  • Module duplication and adaptation
    A module refers to a unit that can be duplicated and further adapted. For example, arthropods have various numbers of body segments. Segment duplication and loss is a developmental change that probably occurred many times in the evolution of this clade. The graphic below shows a hypothetical example of module duplication and adaptation.
  • Individualization
    This is the modification of a particular module, usually when there is selection for a specialized function.

    One set of scorpions’ appendages has evolved into pincers whereas the same appendage in many spiders has evolved into colorful pompoms used in mating rituals. Scorpion image courtesy of the California Academy of Sciences; Spider image courtesy of Michael Hedin, San Diego State University.
  • Heterochrony
    Heterochrony is a change in the timing of developmental events. For example, a change in timing might slow down the development of the body, but not alter the maturation of the reproductive system. This change yields an adult organism with a form similar to the ancestral juvenile form.

    Larval salamander image courtesy of Jeff LeClere; Tiger salamander image courtesy of Greg Sievert; Axolotl image courtesy of Barbara Shardy.

    Salamanders go through a larval stage in which they have feathery, external gills (left). Most salamanders lose these gills when they metamorphose into adults (center). Because of heterochrony, axolotls now retain the juvenile external gills as fully reproductive adults (right).

  • Allometric growth
    Image courtesy of Ben Waggoner

    Allometric growth is a change in the rate of growth of a dimension or feature relative to other features. For example, we can describe some of the evolutionary changes that produced bats in terms of allometry. Bat wings are basically paws with really long fingers and skin stretched between them. In order for these wings to evolve, the rate of growth of finger bones must have increased relative to the growth of the rest of the bat’s body — or perhaps the rate of growth of the rest of the body decreased relative to the fingers. Either way, it is allometry.

  • More Details
  • Evo Examples
  • Teaching Resources

Read more about how development factored into the history of evolutionary thought.

Learn more about evolution and development in context: Why the eye?, a case study.

Teach your students about development:

  • Mealworm metamorphosis, a classroom activity for grades 3-5.
  • From butterflies to humans, a lecture for grades 9-12.

Find additional lessons, activities, videos, and articles that focus on development.

Footer

Connect

  • Email
  • Facebook
  • Twitter

Subscribe to our newsletter

Teach

  • Teaching resource database
  • Correcting misconceptions
  • Conceptual framework and NGSS alignment
  • Image and use policy

Learn

  • Evo 101
  • Evo in the News
  • The Tree Room
  • Browse learning resources
  • Glossary

Copyright © 2023 · UC Museum of Paleontology Understanding Evolution · Privacy Policy