Hi @dcscccc -
I hope you are doing well this day. I do appreciate your answers, we seem to be making progress. Let me summarize my understanding of your predictions based on the creationist model, and you can correct me if I have misunderstood anything:
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Humans actually have a vitellogenin gene; it is not a pseudogene. It is participating in the production of vitellogenin even today among us humans; if you were to take an appropriate blood or tissue sample of a human of the appropriate age, you would find vitellogenin. Vitellogenin does not play the same role as it plays in oviparous vertebrates such as birds, however.
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Opossums have functional vitellogenin genes, which produce vitellogenin in members of the species.
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The discussion of why pseudogenes would be similar or dissimilar in certain circumstances is irrelevant to the question of vitellogenin, because no one has discovered a vitellogenin pseudogene.
I would need only one further piece of information to consider this a logically complete, testable, scientific theory:
What does the creation model predict regarding the function of vitellogenin in humans, opossums, and other non-oviparous vertebrates?
And now let me respond to your question:
In an earlier thread, Dennis stated this:
Vitellogenins are the genes used for bulk yolk transfer in egg-laying organisms. The minuscule amount of yolk found in placentals is not VIT based. So, there is no reason, from a antievolutionary perspective, to find VIT sequences in placental mammals, since placentals have no need for bulk yolk transfer. Evolution, however, predicts that placental mammals are descended from egg-laying ancestors, and thus may retain
fragments of the VIT genes harkening back to that former way of life. If so, these fragments should be in blocks of syntenty conserved with egg-laying vertebrates. So, what we observe in placentals is exactly what evolution would predict.
In his first article in the series, Dennis also stated this:
One example that I have discussed several times in the past is the curious case of vitellogenin pseudogenes in placental mammals. Vitellogenins are large proteins used by egg-laying organisms to provide a store of nutrition to their embryos in egg yolk. Since vitellogenins are so large, they are a good source of amino acids when digested (proteins are made of amino acids linked together). Many of the amino acids in vitellogenins have sugars attached to them as well, so they also serve as a source of carbohydrates. The three-dimensional shape of vitellogenin proteins also acts as a carrier for lipids. As such, vitellogenins can be synthesized in the mother and transferred to the yolk as a ready-made supply of amino acids, sugars, and lipids for the developing embryo.
Placental mammals, on the other hand, use a different strategy for nourishing their embryos during development: the placenta. This connection between the mother and embryo allows for nutrient transfer right up until birth. As such, there is no need for vitellogenins, or storing up a supply in the egg yolk for the embryo to use. Evolutionary biology predicts that placental mammals descend from egg-laying ancestors, however – and one good line of evidence in support of that hypothesis (among many) is that placental mammals, humans included, have the remains of vitellogenin gene sequences in their genomes.
Looking forward to your last answer, so we can look at the evidence together.
Peace,
EDIT: Added link to Dennis Venema’s article