gastraea theory
E465967
The gastraea theory is Ernst Haeckel’s evolutionary hypothesis that all multicellular animals descended from a common, two-layered gastrula-like ancestor, helping to explain the origin of animal body plans.
Observed surface forms (1)
| Surface form | Occurrences |
|---|---|
| Gastraea theory | 0 |
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
evolutionary hypothesis
ⓘ
theory in evolutionary biology ⓘ theory in zoology ⓘ |
| addresses |
common ancestry of multicellular animals
ⓘ
evolution of embryonic germ layers ⓘ |
| aimsToExplain |
evolutionary origin of diploblastic and triploblastic organization
ⓘ
how complex animal tissues evolved from simple layers ⓘ |
| assumes |
a single common metazoan ancestor
ⓘ
homology between gastrula stages of different animals ⓘ |
| basedOn |
comparative embryology
ⓘ
comparative morphology of animal phyla ⓘ recapitulation theory ⓘ |
| concernsStage | gastrula stage of embryonic development ⓘ |
| concernsTaxon | Animalia NERFINISHED ⓘ |
| coreClaim |
all multicellular animals share a common ancestor resembling a gastrula
ⓘ
animal body plans originated from a simple gastrula-like form ⓘ the earliest metazoan ancestor was a two-layered organism ⓘ the metazoan ancestor possessed ectoderm and endoderm germ layers ⓘ |
| critiquedFor |
overreliance on recapitulation
ⓘ
simplified view of early metazoan evolution ⓘ |
| describes |
evolutionary transition from unicellular to multicellular animals
ⓘ
origin of Metazoa ⓘ origin of animal body plans ⓘ |
| field |
comparative morphology
ⓘ
embryology ⓘ evolutionary biology ⓘ zoology ⓘ |
| historicalContext | Darwinian evolutionary synthesis in Germany ⓘ |
| influenced |
early metazoan phylogeny models
ⓘ
historical discussions of animal origins ⓘ the study of germ layer homology ⓘ |
| languageOfOriginalFormulation | German ⓘ |
| proposedBy | Ernst Haeckel NERFINISHED ⓘ |
| proposedInWorkBy | Ernst Haeckel’s writings on the origin of Metazoa ⓘ |
| proposesAncestor | gastraea ⓘ |
| relatedConcept |
Metazoa
NERFINISHED
ⓘ
biogenetic law NERFINISHED ⓘ gastrula ⓘ gastrulation ⓘ germ layers ⓘ |
| status | historically important but partially superseded ⓘ |
| timeProposed |
1870s
ⓘ
19th century ⓘ |
| typeOf | common-ancestor hypothesis ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.