RESUMEN
Müllerian mimicry strongly exemplifies the power of natural selection. However, the exact measure of such adaptive phenotypic convergence and the possible causes of its imperfection often remain unidentified. Here, we first quantify wing colour pattern differences in the forewing region of 14 co-mimetic colour pattern morphs of the butterfly species Heliconius erato and Heliconius melpomene and measure the extent to which mimicking colour pattern morphs are not perfectly identical. Next, using gene-editing CRISPR/Cas9 KO experiments of the gene WntA, which has been mapped to colour pattern diversity in these butterflies, we explore the exact areas of the wings in which WntA affects colour pattern formation differently in H. erato and H. melpomene. We find that, while the relative size of the forewing pattern is generally nearly identical between co-mimics, the CRISPR/Cas9 KO results highlight divergent boundaries in the wing that prevent the co-mimics from achieving perfect mimicry. We suggest that this mismatch may be explained by divergence in the gene regulatory network that defines wing colour patterning in both species, thus constraining morphological evolution even between closely related species.
Asunto(s)
Mimetismo Biológico , Mariposas Diurnas/fisiología , Animales , Mariposas Diurnas/genética , Mariposas Diurnas/crecimiento & desarrollo , Genes de Insecto , Pigmentación/genética , Selección Genética , Alas de AnimalesRESUMEN
Los constreñimientos del desarrollo se ubican en la intersección entre evolución y desarrollo, lo que los convierte en uno de los focos cruciales de investigación en la EvoDevo. Desafortunadamente, tanto el concepto mismo de constreñimiento como sus referencias fácticas han estado rodeados de confusión y controversia, lo que ha impedido un mayor avance en su estudio. En este artículo, tras revisar varios de los textos clásicos sobre constreñimientos, identifico algunas de las fuentes de confusión en torno al tema. Llamo la atención sobre la utilidad de recuperar la taxonomía que divide a los constreñimientos en universales y locales, lo cual brinda enorme claridad en la comprensión de la naturaleza misma del fenómeno. Resalto la necesidad de evitar algunas aproximaciones ortodoxas recurrentes en su estudio, al tiempo que defiendo su importancia como factores del desarrollo con implicaciones evolutivas.
Developmental constraints are located on the interface between evolution and development, which make them a crucial focus of research in EvoDevo. Unfortunately, the concept of constraint and its factual references have been surrounded by confusion and controversy, which have limited the advancement of their study. In this paper, after reviewing some traditional literature on the subject, I identify some specific sources of confusion. I propose to recover the classical taxonomical division of constraints that divide them into universal and local, which brings clarity to the understanding of their nature. I highlight the need of avoiding some recurrent orthodox approaches on the topic, as well as defending their importance as developmental factors that have evolutionary implications.