This article very neatly lays out evidence for a ontogenic pathway of modern feathers, elucidating the main gene players involved. Very nice work. And we already know that ontogeny recapitulates developmental pathways so this study has something important to say about the evolution of feathers. This work is concise, clean, and significant for evolution and development.
The author himself admits that "They also have shown that the evolution from scale to feather most likely followed a path in which the barbs form first and then fuse to produce a rachis – rather than a rachis forming first and then being sculpted into barbs and barbules." Note the underlined words 'most likely'. In other words the experiment gives no such proof. They changed feather formation by altering the expression of three different genes. Each one produced a different effect. There was no attempt at finding out exactly what sequence the chicken's developmental program follows in producing feathers. Therefore such a conclusion is totally unsupported by this experient. It also should be noted that it is the writer of the article which is claimint this conclusion, he is not quoting those who did the experiment.
And, as they didn't use this newly discovered developmental pathway to produce feathers in an unrelated organism (the elephant?) they didn't discover a developmental pathway.
How can one speak of a pathway when we are talking about three different genes being involved in the production of feathers? How can one speak of a pathway when these genes are used in different species to produce different cells and even in the same species to produce different cells at different times in the developmental program. You are talking total nonsense as I have clearly shown in Post# 66 and Post# 81 which you are clearly trying to dismiss without showing a single piece of evidence to refute them. As the article in Post# 31 " Among others, three genes in particular" There are many more genes involved in this, but the author dishonestly dismisses them as needed in feather formation. What these genes are, whether they are particular to birds or not, is not mentioned in the article. They are needed though for feather formation and their absence from the article and from the experiment invalidates the conclusions made in the article. In fact, it invalidates the whole experiment since clearly the 'scientists' were out to prove a pre-determined point, not to really find out what was involved in producing feathers in an animal that did not have feathers.
Further, because they don't accept evolution, they don't accept that the evidence is consistent with evolution. (How's that for logic?) On and on they blather. If they could only hear themselves.
It is you who is blathering. You can show nothing in the article or anywhere else supporting the conclusions of this experiment.
This article very neatly lays out evidence for a ontogenic pathway of modern feathers, elucidating the main gene players involved.
Nonsense. Ontogeny refers to the developmental program by which one cell creates millions or billions of other cells in exactly the right place and of exactly the right kind. The experiment dealt with a grown chicken, it did not even look at how and when the different genes that form the feathers are activated during development.
Very nice work. And we already know that ontogeny recapitulates developmental pathways so this study has something important to say about the evolution of feathers. This work is concise, clean, and significant for evolution and development.
What pathways do you keep talking about? Are they like highways, expressways, parkways? You are talking garbage. Ontogeny means development so all you are stating is 1=1. What you are throwing in is the word 'pathway'. There are no pathways in development. There are numerous genes involved and those genes are turned on and off at different stages of development. Those genes interact with others in complicated ways, acting with different ones at different stages. There are no pathways. All there is is a very specific, very involved program which controls the actions of a multitued of genes at each particular stage.