Abacus

Okay, time to make good use of some valuable resources (you people!).

I recently had someone assert to me that the birth of Dolly (the famous cloned sheep) dealt a harsh blow against darwinian evolution. This person stated that prior to Dolly evolutionary scientists believed that each cell did not contain a complete blueprint for the organism, and when Dolly was born, this school of thought was overturned.

But haven't we known for a long time that the nucleus of each and every cell, be it a liver cell, muscle cell, or whatever, contains all of the genetic information? Or am I missing something?

MortalWombat

Red blood cells in mammals lack nuclei, and thus do not contain a complete blueprint for the organism. Apart from that minor nitpick, I don't know of any "evolutionary scientist" who believed prior to Dolly that each cell did not contain a complete blueprint for the organism. I would ask for a references for this person's assertation.

lpetrich

However, every cell with a nucleus has a complete set of genes.

Undercurrent

And even if they didn't, this would hardly contradict Darwinian evolution. DE requires no assumptions on how the information regarding the structure and delevopement of an organism is contained withing the organism's adult form, and very few assumptions about how the information is passed on to offspring and modified through mutation.

zwi

Gametes however are haploid

An even more mnor nit, but a real one

Zwi

pz

The "blueprint" analogy is deeply flawed and ought to be rejected anyway. The reasons have absolutely nothing to do with Dolly.

Also, Dolly was not really that revolutionary; other animals (like frogs) have been cloned from somatic cells since the late '50s. The idea that the complete set of genetic information was encoded in the nucleus of a single cell has been pretty much dogma since the late 19th century and August Weissman -- an evolutionist.

I suspect your creationist was babbling out of his butt.

pz

Haploid gametes still possess a complete set of genes, however.

mark24

Hi all,

Not sure if you are all aware, but poor ol' Dolly died last week

Mark

Doubting Didymus

I have no doubts at all that this feller is referring to Dawkins discussion of the bauplan analogy. (I've forgotten which book. Probably the blind watchmaker).

Dawkins made a big point of utterly rejecting the bauplan (blueprint) point of weiw, comparing the genetic instructions instead to a recipe, and thus including the importance of the many non-genetic influences on the finished organism that exist.

(Note: Gene centrism is still justified, even in the prescence of bowls, whisks, ovens and baking trays)

Dolly is no exception. She is a 'clone' its true, but she is by no means a copy of her genetic donor. And how could she be? The development of an organism from zygote to adult is of utterly massive importance to the finished product. Clones are likely to be even less like their donor than an identical twin, as twins usually share BOTH their genes AND their developmental influences (especially in the womb). Clones only get half of this picture.

So the idea that dolly supports the bauplan hypothesis is quite absurd, and its most obvious with a moments thought. Surely the person in question has heard of the various problems that dolly has had? She was suspected of premature ageing, among a few other things that her genetic donor did not have. If that doesn't refute the bauplan I don't know what does.

pz

Is not!!!You (and Dawkins?) are using the term "bauplan" in a way that doesn't jibe with how I'd use it. What do you mean? To me, it refers to the high-level spatial organization of positional information in metazoan development. The concept has most definitely not been refuted, but instead has been reinforced in recent years by greater genetic and molecular knowledge.