Comments on: Oh, lemon

By: Sommer

Sommer — Wed, 01 Jul 2009 10:58:41 +0000

I heard that a the egg that has been fertilized by both parents in a tube that is inserted in the serrogate mom, doesn’t get the traits of the serrogate mom bcuz both dna (genes) are from the woman & man who made the baby. Example “serrogate mom is just renting out her womb for a fetus that was scientifically arranged”. Eh its a way I see it. Lol

By: Ampersand

Ampersand — Tue, 26 Sep 2006 13:43:55 +0000

Oh, sorry – I misunderstood what you were arguing.

By: Peter

Peter — Tue, 26 Sep 2006 06:03:49 +0000

I am serious. I was speaking of hereditary traits passed on from parent to child. If a child’s phenotype is at all dependent on the genotype of the surrogate womb in which it developed rather than on its own genotype, then an egg implanted in a foreign womb would exhibit physiological variations deviant from its genetic lineage.
This is a ridiculous oversimplification, but, say you were a test-tube baby whose genetic parents both had blue eyes (as did everyone in their respective family history). You, however have brown eyes, just like you’re surrogate mother. At this point one might begin to wonder whether eye color is dependent on the individual’s genes or the genes of the woman who carried said individual. Sorry to be vague.

By: Ampersand

Ampersand — Mon, 25 Sep 2006 18:37:26 +0000

Indeed if any aspect of our resulting physiology was dependent on evolved conditions within the wombs of our mothers, all those test tube babies out there would exhibit some deviant physiology (which to my knowledge they don’t).

Are you serious?

Test tube babies, in the real world, are eggs that are fertilized in a test tube, but then implanted into a womb. There is no such thing as a test tube baby that hasn’t grown to viability within a womb.

By: Peter

Peter — Mon, 25 Sep 2006 03:16:10 +0000

Also the chart you were looking at was drawn by German zoologist Ernst Haeckel. He was trying to further his theory of Recapitulation wherein as a fetus develops it follows it’s full evolutionary lineage exhibiting at each stage in it’s embryonic development various stages in the physiological evolution of it’s species in general. This does not happen as it turns out. Yes early in our embryonic development we develop gill slits, we do not however develop gills. Check out wikipedia: recapitulation theory for some good information on the abandoned theory.

By: Peter

Peter — Mon, 25 Sep 2006 03:07:49 +0000

Yes!! Very good Adam. Your theory is interesting and shows brilliant reasoning within the context of evolution. Unfortunately the factors that seem to way heavily in ontogeny are all self contained within the embryo. Our physiology (well not mine, but that of all women out there) seems to deliberately prevent “the womb and fertilized egg” from interacting. Hence the placenta, amniotic fluid, etc. Indeed if any aspect of our resulting physiology was dependent on evolved conditions within the wombs of our mothers, all those test tube babies out there would exhibit some deviant physiology (which to my knowledge they don’t). The factors that seem to influence an embryo’s development are all pre-scripted in the embryo’s genes. They are called transcription factors, and determine which genes are expressed in which cell (thereby having some cells become liver cells while others in the same embryo become muscle cells). Regardless, Developmental Biology is the hot bed of new ideas in evolution. The mystery of how a single fertilized egg with a complete genetic recipe becomes the fully developed organism is wildly complex and surprisingly misunderstood.