* Shared ancestry: Animals that share a recent common ancestor inherit similar genetic instructions for development. These instructions are encoded in their DNA and dictate how their embryos grow and differentiate.
* Evolutionary conservation: Developmental processes that are essential for survival are often highly conserved over long evolutionary periods. This means that even distantly related animals may share similar early developmental stages.
Examples of animal pairs with similar embryonic development:
* Humans and chimpanzees: These species are closely related and share very similar embryonic development, reflecting their shared evolutionary history.
* Birds and reptiles: While birds and reptiles have evolved into distinct groups, they share a common ancestor and exhibit similarities in their embryonic development, particularly in the formation of the heart and limbs.
* Mammals and amphibians: These groups are more distantly related, but they still show some similarities in early embryonic stages, such as the formation of the neural tube.
Factors that can influence embryonic development:
* Environmental factors: Environmental conditions, such as temperature, can influence embryonic development.
* Genetic mutations: Changes in the genetic code can lead to variations in embryonic development, sometimes resulting in developmental abnormalities.
In summary, the closer the evolutionary relationship between two animals, the more similar their embryonic development is likely to be.