The Dawkins question, new "information" in the genome?

I mentioned fossils because there is nothing in the record right now showing even the beginnings of transitions. Things appear to be now, aside from adaptations to environment and small mutational changes, to be exactly as they were when they appeared.-Justin

Well, in its simplest form it is only a cell that is light sensitive. We can see this today in some of the simple forms that move towards or away from light sources. We can also see this today in plants that have no eyes at all but react to turn towards a light source.You are aware that plants respond to turn the surface of their leaves towards the sun. One good example is the classic sunflower.If you want to follow this further let me know and I'll point you towards several sites that discuss the development of sight.

---

Aslan is not a Tame Lion

Well, there's this on the genetic basis of eyes in jellyfish:

quote:

---

The Sine oculis/Six class family of homeobox genes in jellyfish with and without eyes: development and eye regeneration.

​

Stierwald M, Yanze N, Bamert RP, Kammermeier L, Schmid V.

​

Institute of Zoology, University of Basel, Biocenter/Pharmacenter, CH-4056 Basel, Switzerland.

​

The development of visual organs is regulated in Bilateria by a network of genes where members of the Six and Pax gene families play a central role. To investigate the molecular aspects of eye evolution, we analyzed the structure and expression patterns of cognate members of the Six family genes in jellyfish (Cnidaria, Hydrozoa), representatives of a basal, non-bilaterian phylum where complex lens eyes with spherical lens, an epidermal cornea, and a retina appear for the first time in evolution. In the jellyfish Cladonema radiatum, a species with well-developed lens eyes in the tentacle bulbs, Six1/2-Cr and Six3/6-Cr, are expressed in the eye cup. Six4/5-Cr is mainly expressed in the manubrium, the feeding, and sex organ. All three Six genes are expressed in different subsets of epidermal nerve cells, possibly of the RFamide type which are part of a net connecting the different eyes with each other and the effector organs. Furthermore, expression is found in other tissues, notably in the striated muscle. During eye regeneration, expression of Six1/2-Cr and Six3/6-Cr is upregulated, but not of Six4/5-Cr. In Podocoryne carnea, a jellyfish without eyes, Six1/2-Pc and Six3/6-Pc are also expressed in the tentacle bulbs, Six1/2-Pc additionally in the manubrium and striated muscle, and Six3/6-Pc in the mechanosensory nematocytes of the tentacle. The conserved gene structure and expression patterns of all Cladonema Six genes suggest broad conservation of upstream regulatory mechanisms in eye development.

---

Or this, on the evolution of eyes:

quote:

---

Eyes: variety, development and evolution.

​

Fernald RD.

​

Neuroscience Program, Stanford University, Stanford, Calif 94305, USA. rfernald@stanford.edu

​

The selective advantages of using light as a source of information are reflected in the diverse types of extant eyes. The physical properties of light restrict how it can be collected and processed, resulting in only eight known optical systems found in animals. Eyes develop through tissue rearrangement and differentiation. Our understanding of the source of genetic information used in developmental programs is growing rapidly and reveals distributions of gene expression with substantial overlap in both time and space. Specific genes and their products are used repeatedly, making causal relationships more difficult to discern. The phenomenon of groups of genes acting together seems to be the rule. Throughout evolution, particular genes have become associated with distinct aspects of eye development, and these suites of genes have been recruited repeatedly as new eyes evolved.

---

I realize that neither of these are what you ask for, but the sudden evolution of an eye, or even basic photosensitive cells is not something that happens with sufficient frequency that we've managed to observe it in the lab in the last 50 years we've been examining genetics.But we know mutation creates genes, and that natural selection changes their frequency. We know that eyes are genetic, and we can trace their genetic ancestry through the genomes of various organisms. In this way we can identify the mutation events that led, each time, to eyes of greater functionality; and eventually, even eyes in the first place.

Do you mean that the things which look most like modern species look like modern species, well fancy that.I take it that the things which look slightly like modern species but more like other fossils are just freakish coincidences.Could you maybe tell us what you would expect a transitional fossil to look like?TTFN,WK

It would seem the proper word should be "infer", not "identify". :bTrue, you don't see eyes popping up in lab experiments. What about examples of early life with no eyes or pretty much anything else organ wise, and then the "next" step? What comes after that in the fossil record, is that even documented or found, how do we know there is nothing in between, how do you know there IS a between?-Justin

Well, take elephants, wooly mammoths, etc. Are you prepared to argue/tell me that they acquired those long trunks without in-between stages of length?-Justin

No, there's considerable difference between the species of today and the species represented in the fossil record.But you need to understand that you have a misapprehension about what a transition in the fossil record would look like. Individuals don't transition. Individuals stay the same species they were born as, throughout their life.It is populations that change and evolve, and there's an enormous fossil record of changing populations; a record that agrees with the genetic evidence to such an unlikely degree that the inescapable conclusion at this time is that our reconstructed phylogenies are largely accurate. That record of changing populations is made of fully-formed, static individuals.

Here's an animal called a "tapir":As you can see, it has a very short trunk.

To what degree do you believe soft tissues like eyes fossilize?

There is an underlying confusion here. The nature of fossils (just bones) is such that having all of them wouldn't make the theory 'certain'.The theory is "how" -- that is by what mechanisms life developed over time. If by "certain" you mean we know each mutation and selection event then of course it will never be certain. The bones won't show that.However, there are way more than enough bones to be as close as we can get to "certain" that evolution (not the mechanism but the fact that life has changed ) has happened (by whatever mechanism). Philosophically science is supposed to remain open to change by continuous checking. However, that life has evolved (by some means) is, in any reasonable sense, absolutely certain.Meanwhile the theory of evolution (what that mechanism was ) is the only viable contender for an explanation that we have.We are way beyond fossils in our checking and developing of our understanding of that. While fossils would be helpful in showing the details of the actual steps taken they would not, I think, help with understanding the details of the theory at all.What we need now is an understanding of gene expression, genotype changes and biochemical pathways.The theory says mutations supply the raw material and that selection drives the process in non random ways. We have a lot of understanding of how that works at a high level.What we will learn in the future is exactly how gene changes can arise (not just "mutation") and how particular ones may be expressed and selected. That is there the theory will be strengthened.

Yes, it does, just like elephants have long ones. I don't see how you get from that to elephants without having some sort of "evolution". Do you see what I am getting at? Did a population of tapirs suddenly have kids with long trunks? If not, why not? Is there another explanation? If so, where is *any* showing of this in the fossil record, or anywhere else for that matter?-Justin

I am not saying that changes in populations don't occur. I'm saying I don't see populations becoming far different-looking populations.It seems to me that you must *infer* that in fact these changes took place and we got different structured animals, such as the wooly mammoth, from the tapir or something similar.Look at my response to the tapir thing.-JustinThis message has been edited by creationistal, 09-30-2004 11:24 AM

If you believe that a theory based on inference is a viable contender, that is. I'm still undecided on how much of the current ToE I can accept given mathematics and the 2nd law of thermodynamics. There is a certain quality to life that is undeniable, that it does indeed flourish where it shouldn't, or we think couldn't, etc.But I'm still grappling with the concept that, by chance, with incredibly *small* chances of getting what we have now, or any viable alternative, that single-celled organisms developed into humans, given *any* amount of time.-Justin

In the fossil record? Or now?There's certainly a record of population change in the fossil record. And there's certainly been observation of population change in today's living populations. But they don't become radically different organisms in one generation; it's a slow process of change. Well, we do infer it. We infer it from the observation of the same kind of change occuring today. Darwin didn't propose NS and RM just by looking at fossils; he proposed it by examination of living populations and the effects that selection can have on them. Since his time we've substantialy increased our observations of the change that NS and RM are capable of; we've come to realize that NS and RM are inescapable forces in the natural world, and so, theymust also apply to living things in the past.

All theories are based on inference, from the kinetic theory of gases to the germ theory of disease. That's why our conclusions are tentative. Evolution contradicts neither mathematics nor the Second Law. In fact, the Second Law is what makes evolution possible. When someone wins the lottery, do you grapple with the incredibly small chance that they would have won? Why or why not? It seems to me like you accept improbable events all the time. What's the fundamental difference between humans and single-celled organisms? Aren't they both based on genetics?