1
|
Ollonen J, Khannoon ER, Macrì S, Vergilov V, Kuurne J, Saarikivi J, Soukainen A, Aalto IM, Werneburg I, Diaz RE, Di-Poï N. Dynamic evolutionary interplay between ontogenetic skull patterning and whole-head integration. Nat Ecol Evol 2024; 8:536-551. [PMID: 38200368 DOI: 10.1038/s41559-023-02295-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 11/29/2023] [Indexed: 01/12/2024]
Abstract
The arrangement and morphology of the vertebrate skull reflect functional and ecological demands, making it a highly adaptable structure. However, the fundamental developmental and macroevolutionary mechanisms leading to different vertebrate skull phenotypes remain unclear. Here we exploit the morphological diversity of squamate reptiles to assess the developmental and evolutionary patterns of skull variation and covariation in the whole head. Our geometric morphometric analysis of a complex squamate ontogenetic dataset (209 specimens, 169 embryos, 44 species), covering stages from craniofacial primordia to fully ossified bones, reveals that morphological differences between snake and lizard skulls arose gradually through changes in spatial relationships (heterotopy) followed by alterations in developmental timing or rate (heterochrony). Along with dynamic spatiotemporal changes in the integration pattern of skull bone shape and topology with surrounding brain tissues and sensory organs, we identify a relatively higher phenotypic integration of the developing snake head compared with lizards. The eye, nasal cavity and Jacobson's organ are pivotal in skull morphogenesis, highlighting the importance of sensory rearrangements in snake evolution. Furthermore, our findings demonstrate the importance of early embryonic, ontogenetic and tissue interactions in shaping craniofacial evolution and ecological diversification in squamates, with implications for the nature of cranio-cerebral relations across vertebrates.
Collapse
Affiliation(s)
- Joni Ollonen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Eraqi R Khannoon
- Biology Department, College of Science, Taibah University, Al Madinah Al Munawwarah, Saudi Arabia
- Zoology Department, Faculty of Science, Fayoum University, Fayoum, Egypt
| | - Simone Macrì
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Vladislav Vergilov
- National Museum of Natural History, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Jaakko Kuurne
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Jarmo Saarikivi
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Arttu Soukainen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Ida-Maria Aalto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ingmar Werneburg
- Senckenberg Centre for Human Evolution and Palaeoenvironment, Eberhard Karls Universität, Tübingen, Germany
- Fachbereich Geowissenschaften, Eberhard Karls Universität, Tübingen, Germany
| | - Raul E Diaz
- Department of Biological Sciences, California State University, Los Angeles, CA, USA
- Department of Herpetology, Natural History Museum of Los Angeles County, Los Angeles, CA, USA
| | - Nicolas Di-Poï
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
| |
Collapse
|
2
|
Knoll F, Ishikawa A, Kawabe S. A proxy for brain-to-endocranial cavity index in non-neornithean dinosaurs and other extinct archosaurs. J Comp Neurol 2024; 532:e25597. [PMID: 38588163 DOI: 10.1002/cne.25597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/30/2023] [Accepted: 02/09/2024] [Indexed: 04/10/2024]
Abstract
Although the brain fills nearly the entire cranial cavity in birds, it can occupy a small portion of it in crocodilians. The lack of data regarding the volumetric correspondence between the brain and the cranial cavity hampers thorough assessments of the degree of encephalization in non-neornithean dinosaurs and other extinct archosaurs and, consequently, informed inferences regarding their cognitive capacities. Existing data suggest that, across extant archosaurs, the degree of endocranial doming and the volume of intracranial nonneural components are inversely related. We build upon this information to develop an equation relating these two anatomical features in non-neornithean dinosaurs and other extinct archosaurs. We rely on measurements of the endocast doming and brain-to-endocranial cavity (BEC) index in extant relatives of non-neornithean dinosaurs, namely, the crurotarsans Caiman crocodilus, Crocodylus niloticus, and Crocodylus porosus; the paleognaths Struthio camelus and Apteryx mantelli; and the fowl Macrocephalon maleo, Gallus gallus, Meleagris gallopavo, Phasianus colchicus, and Anas platyrhynchos. Applying the equation to representative endocasts from major clades of dinosaurs, we found that BEC varies from about 0.6 in ceratopsians and thyreophorans to around 0.7 in ornithopods, pachycephalosaurians, sauropods, and theropods. We, therefore, warn against the use of a catch-all value, like 0.5, and instead encourage refinement in the adoption of BEC across archosaurs.
Collapse
Affiliation(s)
- Fabien Knoll
- Departamento de Paleobiología, Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain
| | - Asato Ishikawa
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Eiheiji, Japan
| | - Soichiro Kawabe
- Institute of Dinosaur Research, Fukui Prefectural University, Eiheiji, Japan
- Fukui Prefectural Dinosaur Museum, Katsuyama, Japan
| |
Collapse
|
3
|
Kozol RA, Conith AJ, Yuiska A, Cree-Newman A, Tolentino B, Benesh K, Paz A, Lloyd E, Kowalko JE, Keene AC, Albertson C, Duboue ER. A brain-wide analysis maps structural evolution to distinct anatomical module. eLife 2023; 12:e80777. [PMID: 37498318 PMCID: PMC10435234 DOI: 10.7554/elife.80777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/26/2023] [Indexed: 07/28/2023] Open
Abstract
The vertebrate brain is highly conserved topologically, but less is known about neuroanatomical variation between individual brain regions. Neuroanatomical variation at the regional level is hypothesized to provide functional expansion, building upon ancestral anatomy needed for basic functions. Classically, animal models used to study evolution have lacked tools for detailed anatomical analysis that are widely used in zebrafish and mice, presenting a barrier to studying brain evolution at fine scales. In this study, we sought to investigate the evolution of brain anatomy using a single species of fish consisting of divergent surface and cave morphs, that permits functional genetic testing of regional volume and shape across the entire brain. We generated a high-resolution brain atlas for the blind Mexican cavefish Astyanax mexicanus and coupled the atlas with automated computational tools to directly assess variability in brain region shape and volume across all populations. We measured the volume and shape of every grossly defined neuroanatomical region of the brain and assessed correlations between anatomical regions in surface fish, cavefish, and surface × cave F2 hybrids, whose phenotypes span the range of surface to cave. We find that dorsal regions of the brain are contracted, while ventral regions have expanded, with F2 hybrid data providing support for developmental constraint along the dorsal-ventral axis. Furthermore, these dorsal-ventral relationships in anatomical variation show similar patterns for both volume and shape, suggesting that the anatomical evolution captured by these two parameters could be driven by similar developmental mechanisms. Together, these data demonstrate that A. mexicanus is a powerful system for functionally determining basic principles of brain evolution and will permit testing how genes influence early patterning events to drive brain-wide anatomical evolution.
Collapse
Affiliation(s)
- Robert A Kozol
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Andrew J Conith
- Department of Biology, University of Massachusetts AmherstAmherstUnited States
| | - Anders Yuiska
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Alexia Cree-Newman
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Bernadeth Tolentino
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Kasey Benesh
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Alexandra Paz
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| | - Evan Lloyd
- Department of Biology, Texas A&M UniversityCollege StationUnited States
| | - Johanna E Kowalko
- Department of Biological Sciences, Lehigh UniversityBethlehemUnited States
| | - Alex C Keene
- Department of Biology, Texas A&M UniversityCollege StationUnited States
| | - Craig Albertson
- Department of Biology, University of Massachusetts AmherstAmherstUnited States
| | - Erik R Duboue
- Jupiter Life Science Initiative, Florida Atlantic UniversityJupiterUnited States
| |
Collapse
|