Innovation, Speciation: strange DNA finding (Evolution)

by David Turell , Wednesday, October 16, 2019, 15:14 (1654 days ago) @ David Turell
edited by David Turell, Wednesday, October 16, 2019, 15:26

Once again a new study does not find descent with modification at the genome level, in embryo formation:

https://elifesciences.org/articles/46711

"Abstract
Unrelated genes establish head-to-tail polarity in embryos of different fly species, raising the question of how they evolve this function. We show that in moth flies (Clogmia, Lutzomyia), a maternal transcript isoform of odd-paired (Zic) is localized in the anterior egg and adopted the role of anterior determinant without essential protein change. Additionally, Clogmia lost maternal germ plasm, which contributes to embryo polarity in fruit flies (Drosophila). In culicine (Culex, Aedes) and anopheline mosquitoes (Anopheles), embryo polarity rests on a previously unnamed zinc finger gene (cucoid), or pangolin (dTcf), respectively. These genes also localize an alternative transcript isoform at the anterior egg pole. Basal-branching crane flies (Nephrotoma) also enrich maternal pangolin transcript at the anterior egg pole, suggesting that pangolin functioned as ancestral axis determinant in flies. In conclusion, flies evolved an unexpected diversity of anterior determinants, and alternative transcript isoforms with distinct expression can adopt fundamentally distinct developmental roles."

***

"eLife digest
With very few exceptions, animals have ‘head’ and ‘tail’ ends that develop when they are an embryo. The genes involved in specifying these ends vary between species and even closely-related animals may use different genes for the same roles. For example, the products of two unrelated genes called bicoid in fruit flies and panish in common midges accumulate at one end of their respective eggs to distinguish head from tail ends. It remained unclear how other fly species, which have neither a bicoid nor a panish gene, distinguish the head from the tail end, or how genes can evolve the specific function of bicoid and panish.

***

"Here, Yoon et al. identified three unrelated genes that perform similar roles to bicoid and panish in the embryos of several different moth flies and mosquitoes. These genes appear to have acquired their activity because one of their alternative transcripts accumulated at the future head end, rather than through mutations in the protein-coding sequences. Studying multiple species also made it clear that panish inherited its function from a localized alternative transcript of an old gene that duplicated and diverged.

"These findings suggest that alternative transcription may provide opportunities for genes to evolve new roles in fundamental processes in flies. Most animal genes use alternative start and stop sites for transcription, but the reasons for this remain largely obscure. This is especially the case in the human brain. The findings of Yoon et al., therefore, raise the question of whether alternative transcription has played an important role in the evolution of the human brain." (my bold)

Comment: Note Cornelius Hunter's take: "The genetics and molecular mechanisms involved in animal egg orientation should reveal a “grand pattern” of similarity across different species, especially closely-related ones.

***

Evolutionists cannot have it both ways. They cannot prove their theory when the findings work for them, and softly walk away when the findings do not work. If Evidence X is a powerful proof text of evolution, then Evidence NOT X is a monumental falsification."

https://darwins-god.blogspot.com/2019/10/new-research-on-animal-egg-orientation.html

These closely related insects set up their embryological orientation in different genetic ways.

Also note my bold in the digest. A guide to how God dabbles to create a new form of human brain. Phenotype may look like descent with modification, but the secrets of modification lie in the genome alterations, which appear to be unrelated, not modified