Haeckel‘s theory: Ontogeny recapitulates phylogeny （ 1874 ） the fetal development of an individual (ontogeny) is a speeded-up replay of millions of years of species evolution (phylogeny)
Thomas Hunt Morgan, “Embryology and Genetics” (1934) 第一次提出了胚胎发育的可能细胞分化机制：基因表达的时空分化 在过去的 30 年中，我们已经发现了各种动物均使用的发育调控基因 基本的细胞过程，形成了 “ 进化发育生物学 ” 这一分支学科。 进化发育生物学（ evolutionary developmental biology ）： 旨在阐明生物进化中发育过程和机制怎样改变以及这些改变如何造就过去 和现在的生物多样性的一门学科。（ Baguna and Garcia-Fernandez, 2003). 物种之间发育基因的比较（ Sean Carrol ， 2005 ） 常简称 “Evo Devo”
Evo Devo Evolutionary development is so new there isn’t even consensus as to how to spell it. We spell it “evo devo” because that’s how Sean Carroll spells it. Others spell it “evo-devo” and “evodevo.”
"Evo-devo" is one of the newest areas of biology. It seeks to explain evolutionary events through the mechanisms of developmental biology. Its major questions are often the questions of the late 1800s which had been left waiting for other generations of biologists to unravel. We are those generations. These questions include: How did wings evolve? How did limbs evolve? How did vertebrates arise from invertebrates? How did vertebrates form their head? The Modern Synthesis of the 1930s and 1940s was the synthesis of evolutionary biology and population genetics. It is one of the greatest explanatory systems in science, and it explains incredibly well the origin, maintenance, and evolution of variations within populations of species. However, it did not identify the genes involved in these changes, nor did it explain the origin of higher taxa. Evolutionary developmental biology seeks to “complete” the synthesis by adding developmental genetics to population genetics. Traditional Evo-devo looks at the regulatory regions of genes rather than their coding sequences. It emphasizes the arrival of the fittest rather than the survival of the fittest.
No crossing over Subject to relentless selective sweep and background selection in populations Drosophila Chromosome
Polymorphism of gene toy and sphinx in a worldwide and a local Drosophila melanogaster population Wang, W., Thornton, K., Berry, A. and Long, M. 2002, Science, 295:
Variations in 18 gene regions were investigated Wang, W., Thornton, K., Berry, A. and Long, M. 2002, Science, 295:
Evo-Devo 中的重要概念 : (1) Toolkit genes: master genes that govern the formation and patterning of their Bodies and body parts of all kinds of animals during development. Despite being morphologically very diverse, multicellular organisms are made by a very conserved set of regulatory genes (tool kit genes) playing comparable developmental roles. This most unexpected finding represented a powerful molecular proof of evolution as ‘descent with modification’ (Darwin, 1859). Nonetheless, it brings a big paradox: if developmental genes are the same, how are differences in development and in the final morphology in different organisms to be accounted for? The likely answer: differences between close organisms are due to differences in expression of regulator genes driven by upstream regulators or by changes in the range of downstream target genes.
If one of the Hox genes doesn’t work… Reduced expression of UbxAntp mutant
Ubx 突变对昆虫和节肢动物足肢的影响 果蝇 蜈蚣
Despite featuring a simple structure with a single body axis and radial symmetry, Cnidarians bear the main elements of the genetic toolkit (Finnerty and Martindale, 1999; Hobmayer et al., 2000; Spring et al., 2002; Scholz and Technau, 2003; Yanze et al., 2001; Hayward et al., 2002; Kozmik et al., 2003; Seipp et al., 2001, Wikramanayake et al., 2003). In other words, Hox/ParaHox gene clusters, several anteroposterior (or AP) genes (Otx, emx,..), the main set of endodermal and mesodermal genes (Brachyury, Fork Head, snail/ slug, twist, MyoD, Mef2, dpp/BMPs, Wnt/ß-catenin,…), Pax genes, germ cell genes (vasa, nanos ), as well as several genes involved in apoptotic processes, were already in place 600 million of years ago. Evidence of such an extensive toolkit in Cnidarians debunks the notion that gene diversification was at the base of the so-called Cambrian explosion, whatever this may mean today (see Conway-Morris, 2003).
(2) Phylogeny ( 系统发育 ) Evolutionary-based questions have to be framed into a meaningful phylogenetic framework; otherwise, whether a particular morphology is ancestral or derived, whether a new morphology is due to gain or loss of a feature, or whether a morphology has evolved once or many times can not be properly answered unless phyletic relationships among the comparing clades is known.
(3) Homology vs. convergent, parallel and homoplasmy Sorting out parallelism from homology in landmark issues such as the origin(s) of segmentation,the origin(s) of the eye (Hodin, 2000) warrants further studies of additional phyla, and a deep understanding of plasticity and constraints in gene and developmental evolution. When a structure which is homologous between closely related organisms is built using different genes, it should be considered convergent rather than homologous. Homologous genes may be responsible for non-homologous morphologies. Genes and pathways are utilized on many separate occasions during development. As examples, the Notch-signalling pathway is broadly used during Drosophila and vertebrate development (Simpson, 1997; Robey, 1997), and hedgehog, TGF-β and Wnt family members are used over and over again during development. Evolution may well have worked by “genetic tinkering” (Jacob, 1977) or “bricolage” of gene networks (Duboule and Wilkins, 1998). paralogues, orthologues Paralogues: 源自基因重复；共同祖先是基因。 Orthologues ：源自祖先物种，共同祖先是物种。
variety of eye types closely related animals have closely related eye genes, which would result in similar eyes. Vertebrates: camera-like eyes with a single lens. Flies, lobsters and other arthropods: compound eyes made up of many eye units. 都是同源的 pax-6 相关 pathway 控制，但最终形态不一样
Macroevolution vs. microevolution As Dobzhansky (1937) firstly pointed out, the main issue in the macro vs. microevolution debate is whether mutations resulting in real evolutionary novelties are of the same kind as those occurring daily or whether we should expect special, rare mutations only occurring on geological time scales.
The future task for macro-Evo-Devo will be to unravel: i) preexisting developmental potential; in other words, what was before the Cambrian, which means analyzing the developmental toolkit component of the closest sister groups, relatives of eubilaterians, the acoelomorph flatworms (Ruiz-Trillo et al., 1999; 2002); ii) the extent and quality of bricolage of this basal bilaterian toolkit compared to higher bilaterians; and iii) trying to link the known, and those which remain to be discovered, fossil groups Ongoing debates or unsolved questions in evolutionary developmental biology Origin of Bilateria Origin of Vertebrata Origin of Birds Origin of Limbs Origin of Brain Multicellularity??
In the late 60s, population and quantitative genetics showed a high deal of genetic variation within populations. Evolutionary developmental biologists thought of this intraspecific variation in regulatory developmental genes as mere “noise”. However, new applications of population genetics and artificial selection techniques to test the potential of variation in developmental features is switftly changing this appreciation. Six generations of artificial selection on wing eyespot size in the butterfly Bicyclus, led to dramatic shifts in the range of eyespot sizes (reviewed in Beldade and Brakefield, 2002). Further, Gompel and Carroll (2003) and Sucena et al., (2003) have identified minor genetic changes correlating with microevolutionary features in closely related Drosophila species: the distribution of tricomes, or the pigmentation of the abdomen. To start with, it seems wiser to leave aside big hot problems such as the basis of the “Cambrian explosion” (despite their tremendous interest) and concentrate on intra-phyletic, and even better intraclass, intra-order and inter-generic, comparisons. Among the best examples of this approach one could mention the role of Ultrabithorax in morphological differences between Drosophila species (Stern, 1998), the divergence of cis-regulatory sequences in the achaetescute gene complex between Drosophila melanogaster and D. simulans (Skaer and Simpson, 2000), the variability among the evenskipped stripe 2 in Drosophila (Ludwig et al., 2000).
Loss of an Enhancer in Stickleback Fish Evolution leads to dramatic morphological difference 但 Hoskstra 和 Coyne 认为 1 、仅仅排除 pitx1 编码区的突变就认定是 cis 改变证据不足 2 、不能排除其他基因编码区的突变 Hoskstra and Coyne ， 2007, Evolution 61-5:
Butterfly Wing Pattern Evolution Is Associated with Changes in a Notch/Distal-less Temporal Pattern Current biology 2004, 13: