{"id":53,"date":"2025-08-14T10:54:05","date_gmt":"2025-08-14T10:54:05","guid":{"rendered":"https:\/\/new.alexasadier.com\/?page_id=53"},"modified":"2025-08-15T14:43:40","modified_gmt":"2025-08-15T14:43:40","slug":"research","status":"publish","type":"page","link":"https:\/\/alexasadier.com\/index.php\/research\/","title":{"rendered":"RESEARCH"},"content":{"rendered":"\n<h1 class=\"wp-block-heading has-text-align-center has-text-color has-link-color wp-elements-ce74790f580dc70c14f4d1c66dcbc0db\" style=\"color:#f2d1b3;padding-top:var(--wp--preset--spacing--x-small);padding-bottom:var(--wp--preset--spacing--x-small);font-size:clamp(28.836px, 1.802rem + ((1vw - 3.2px) * 1.873), 50px);\">RESEARCH THEMES<\/h1>\n\n\n\n<figure class=\"wp-block-image alignwide size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"334\" src=\"http:\/\/new.alexasadier.com\/wp-content\/uploads\/2025\/08\/20190616_172834crop2-2048x668-1-1024x334.jpg\" alt=\"\" class=\"wp-image-213\" srcset=\"https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/20190616_172834crop2-2048x668-1-1024x334.jpg 1024w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/20190616_172834crop2-2048x668-1-300x98.jpg 300w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/20190616_172834crop2-2048x668-1-2000x652.jpg 2000w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/20190616_172834crop2-2048x668-1.jpg 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:var(--wp--preset--spacing--medium);margin-bottom:var(--wp--preset--spacing--medium)\"\/>\n\n\n\n<div class=\"wp-block-cover\" style=\"min-height:1018px;aspect-ratio:unset;\"><img decoding=\"async\" width=\"2319\" height=\"2005\" class=\"wp-block-cover__image-background wp-image-340 size-full\" alt=\"\" src=\"https:\/\/new.alexasadier.com\/wp-content\/uploads\/2025\/08\/Asset-1@4x.png\" data-object-fit=\"cover\" srcset=\"https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Asset-1@4x.png 2319w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Asset-1@4x-300x259.png 300w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Asset-1@4x-1024x885.png 1024w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Asset-1@4x-2000x1729.png 2000w\" sizes=\"(max-width: 2319px) 100vw, 2319px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-background-dim-0 has-background-dim\" style=\"background-color:#1c1815\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<p class=\"has-text-align-center has-large-font-size\"><\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group has-global-padding is-layout-constrained wp-block-group-is-layout-constrained\">\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:var(--wp--preset--spacing--x-small);margin-bottom:var(--wp--preset--spacing--x-small)\"\/>\n\n\n\n<h2 class=\"wp-block-heading has-large-font-size\" id=\"inspiro-is-a-digital-product-agency-that-focuses-on-strategy-and-design\" style=\"font-style:normal;font-weight:100\"><\/h2>\n\n\n\n<div style=\"height:54px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image aligncenter size-full\"><img decoding=\"async\" width=\"247\" height=\"259\" src=\"https:\/\/new.alexasadier.com\/wp-content\/uploads\/2025\/08\/tooth-model.png\" alt=\"\" class=\"wp-image-342\"\/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-secondary-color has-text-color has-medium-font-size\"><strong>Evolutionary novelties<\/strong><\/h3>\n\n\n\n<p class=\"has-text-align-left has-text-color\" style=\"color:#f2d1b3\">One long-standing question in evolutionary biology is: how do new morphological innovations arise? While ntegrative advances in palaeontology, genomics, development and evolution have unveiled general principles behind evolutionary novelties, we are far from understanding the mechanisms by which novelties emerge and diversify in new ecological contexts. To solve this problem, we use the dramatic morphological and ecological diversity of bat teeth as a model system to study the origin and diversification of a major mammalian innovation, the tooth classes. <\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"613\" height=\"561\" src=\"https:\/\/new.alexasadier.com\/wp-content\/uploads\/2025\/08\/Capture-decran-2025-08-15-162929.png\" alt=\"\" class=\"wp-image-344\" style=\"width:288px;height:auto\" srcset=\"https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Capture-decran-2025-08-15-162929.png 613w, https:\/\/alexasadier.com\/wp-content\/uploads\/2025\/08\/Capture-decran-2025-08-15-162929-300x275.png 300w\" sizes=\"(max-width: 613px) 100vw, 613px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-secondary-color has-text-color has-medium-font-size\">Developmental constraints<\/h3>\n\n\n\n<p class=\"has-text-color\" style=\"color:#f2d1b3\">Why some morphologies frequently evolve, while others, though theoretically possible, never arise?  As phenotypes are the product of phenotypes through development, this paradox has often been explained by the existence of biases or contraints on developmental processes. While the genomic and ecological drivers of variation in adult morphologies have been a frequent and productive subject of study, how developmental processes facilitate or constrain morphological evolution remains poorly understood. In our lab, we use teeth and ectodermal appendages to decipher how developmental constraints both limit and facilitate the evolution of phenotypes on Earth and beyond.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"285\" src=\"https:\/\/new.alexasadier.com\/wp-content\/uploads\/2025\/08\/cochlea-300x285-1.jpg\" alt=\"\" class=\"wp-image-345\" style=\"width:277px;height:auto\"\/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-secondary-color has-text-color has-medium-font-size\"><strong>Sensory adaptations<\/strong><\/h3>\n\n\n\n<p class=\"has-text-color\" style=\"color:#f2d1b3\">Bats have evolved specialized sensory systems to forage, hunt and orientate themselves, sometimes in complete darkness. Like many other traits, sensory systems like vision and echolocation have diversified following the colonization of various dietary niches. In the lab, we study the evolution of vision and echolocation using intergative approaches during development. We showed that color vision is mosaic in Noctilionoid bats, UV vision being lost multiple time independently. We also showed that the development of the bat cochlea constraint the development of other sensory systems.<\/p>\n<\/div>\n<\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" style=\"margin-top:var(--wp--preset--spacing--small);margin-bottom:var(--wp--preset--spacing--small)\"\/>\n<\/div>\n\n\n\n<p><strong><em>Work related to the origin and diversification of mammalian tooth classes and developmental constraints: <\/em><\/strong><\/p>\n\n\n\n<p>Sadier, A., Anthwal, N., Krause, A.L.&nbsp;<em>et al.<\/em>&nbsp;Bat teeth illuminate the diversification of mammalian tooth classes.&nbsp;<em>Nat Commun<\/em>14, 4687 (2023).&nbsp;<a href=\"https:\/\/doi.org\/10.1038\/s41467-023-40158-4\">https:\/\/doi.org\/10.1038\/s41467-023-40158-4&nbsp;<\/a><a href=\"https:\/\/www.nature.com\/articles\/s41467-023-40158-4.pdf\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p>Grossnickle, D. M., Sadier, A.<strong>,<\/strong>\u00a0Patterson, E., Cort\u00e9s-Viruet, N. N., Jim\u00e9nez-Rivera, S. M., Sears, K. E., &amp; Santana, S. E. (2024). The hierarchical radiation of phyllostomid bats as revealed by adaptive molar morphology. Current Biology.\u00a0<a href=\"https:\/\/doi.org\/10.1016\/j.cub.2024.02.027\">https:\/\/doi.org\/10.1016\/j.cub.2024.02.027<\/a><\/p>\n\n\n\n<p>Sadier, A., Twarogowska, M., Steklikova, K., Hayden, L., Lambert, A., Schneider, P., Laudet, V., Hovorakova, M., Calvez, V., and Pantalacci, S. (2019). Modeling Edar expression reveals the hidden dynamics of tooth signaling center patterning. PLoS Biol 17, e3000064 https:\/\/doi.org\/10.1371\/journal.pbio.3000064<\/p>\n\n\n\n<p><strong>Sadier A.<\/strong>, Sears, K. and Womack, M. Unravelling the heritage of lost traits,\u00a0<strong>J Exp Part B.\u00a0<\/strong>https:\/\/doi.org\/10.1002\/jez.b.23030<a href=\"https:\/\/doi.org\/10.1016\/j.cub.2024.02.027\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p><strong><em>Work related to bat vision and cochlea evolution:<\/em><\/strong><\/p>\n\n\n\n<p>Anthwal, N., Hall, R. P., de la Rosa Hernandez, F. A., Koger, M., Yohe, L. R., Hedrick, B. P., Davies, K. T. J., Mutumi, G. L., Roseman, C. C., Dumont, E. R., Davalos, L. M., Rossiter, S. J., Sadier*, A. (co-last), &amp; Sears*, K. E. (2023). Cochlea development shapes bat sensory system evolution. The Anatomical Record, 1\u201312.\u00a0<a href=\"https:\/\/doi.org\/10.1002\/ar.25353\">https:\/\/doi.org\/10.1002\/ar.25353<\/a><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/pdfdirect\/10.1002\/ar.25353\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p>Sadier*, A., Davies*, K.T., Yohe, L.R., Yun, K., Donat, P., Hedrick, B.P., Dumont, E.R., Davalos, L.M., Rossiter, S.J., and Sears, K.E. (2018). Multifactorial processes underlie parallel opsin loss in neotropical bats. Elife 7.\u00a0<a href=\"https:\/\/elifesciences.org\/articles\/37412\">https:\/\/elifesciences.org\/articles\/37412<\/a><\/p>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p><strong><em>Work related to bat evolution and ecology:<\/em><\/strong><\/p>\n\n\n\n<p>Sharlene E Santana,&nbsp;<strong>Alexa Sadier<\/strong>, Marco A R Mello, (2024). The ecomorphological radiation of phyllostomid bats, Evolutionary Journal of the Linnean Society,&nbsp;<a href=\"https:\/\/doi.org\/10.1093\/evolinnean\/kzae032\">https:\/\/doi.org\/10.1093\/evolinnean\/kzae032<\/a><\/p>\n\n\n\n<p><strong>\u00a0Sadier A,<\/strong>\u00a0Urban DJ, Anthwal N, Howenstine AO, Sinha I, Sears KE, Sadier A, Urban DJ, Anthwal N, Howenstine AO, Sinha I, Sears KE. 2020. Making a bat: The developmental basis of bat evolution.<strong>\u00a0Genetics and Molecular Biology\u00a0<\/strong><a href=\"http:\/\/dx.doi.org\/10.1590\/1678-4685-gmb-2019-0146\">http:\/\/dx.doi.org\/10.1590\/1678-4685-gmb-2019-0146<\/a><\/p>\n\n\n\n<div style=\"height:35px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p><strong><em>Work related to EDA pathway evolution:<\/em><\/strong><\/p>\n\n\n\n<p>Sadier, A., Lambert, E., Chevret, P., Decimo, D., Semon, M., Tohme, M., Ruggiero, F., Ohlmann, T., Pantalacci, S., and Laudet, V. (2015). Tinkering signaling pathways by gain and loss of protein isoforms: the case of the EDA pathway regulator EDARADD. BMC Evol Biol 15, 129. https:\/\/doi.org\/10.1186\/s12862-015-0395-0<a href=\"https:\/\/bmcecolevol.biomedcentral.com\/counter\/pdf\/10.1186\/s12862-015-0395-0\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p>Sadier, A., Viriot, L., Pantalacci, S., and Laudet, V. (2014). The ectodysplasin pathway: from diseases to adaptations. Trends Genet 30, 24\u201331. https:\/\/doi.org\/10.1016\/j.tig.2013.08.006<a href=\"https:\/\/api.istex.fr\/ark:\/67375\/6H6-C36G17DN-H\/fulltext.pdf?sid=clickandread\" target=\"_blank\" rel=\"noreferrer noopener\"><\/a><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>RESEARCH THEMES Evolutionary novelties One long-standing question in evolutionary biology is: how do new morphological innovations arise? While ntegrative advances in palaeontology, genomics, development and evolution have unveiled general principles behind evolutionary novelties, we are far from understanding the mechanisms by which novelties emerge and diversify in new ecological contexts. To solve this problem, we &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/alexasadier.com\/index.php\/research\/\" class=\"more-link\">Read more<span class=\"screen-reader-text\"> &#8220;RESEARCH&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-templates\/no-title.php","meta":{"footnotes":""},"class_list":["post-53","page","type-page","status-publish","hentry"],"featured_media_urls":[],"_links":{"self":[{"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/pages\/53","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/comments?post=53"}],"version-history":[{"count":20,"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/pages\/53\/revisions"}],"predecessor-version":[{"id":365,"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/pages\/53\/revisions\/365"}],"wp:attachment":[{"href":"https:\/\/alexasadier.com\/index.php\/wp-json\/wp\/v2\/media?parent=53"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}