Tony
Penultimate Amazing
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That was my reaction. What's a genome for starters?
That was my reaction. What's a genome for starters?
Lukraak_Sisser
Philosopher
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During reproduction the genome of the original cell gets duplicated and divided equally between the two daughter cells.
But this does not always go 100% well, leading to partial or even whole genomes being duplicated in one cell and absent in the other.
The cell getting the short end of the stick dies, the other cell now has a segment of DNA that is redundant, but not detrimental.
This extra DNA gets treated as normal, so from then on the new daughter cells will have these extra genes coding for material already present.
Due to the redundancy of these extra genes there is no evolutionary pressure to keep them as they are, so one of each of the duplicated genes can start mutating without adversly affecting the cell. Such genes can then evolve into new genes that can give these cells the ability to do things their ancestors could not, and at some point these genes become essential in their own right, having become something different.
Evidence for this can be found in genetic analysis of multiple organisms AND has been verified by experimentation.
(this is of course a VERY abbreviated summation of a massive field of study)
De Grasse was just one of the more prominent scientists and biologists of the 20th century and said those things in the 70s. You can google the others though right now, I am not sure if was Bloome or Broome, and they all spoke about "evolution" defined as the current, accepted theory of evolution in the manner I described it. Grasse quite plainly said "evolution was a myth."
Also, you asked me to name one biologist that was not an evolutionist. So I did. Now, you say it's an appeal to authority.
Clearly, that was an appeal to authority on your part in the first place. I was just pointing out it was false on it's face to suggest no biologists reject darwinism (my term for the theory of evolution taught today), but if you want to never use such an argument, fine with me. Please don't ever suggest just because some scientific organization or most scientists or some scientist believes in evolution, that it must be true.
Why? Are you saying if someone cannot show a prior fossil or living or dead specimen, that we should reject common ancestry?
Ok, but that means you need to reject Darwinism because you don't see the common ancestors, do you?
If you disagree, please show me the original species that evolved into bears, a living or dead specimen or a fossil, please.
which question?
Actually there is but let's deal with the 2nd question. Adaptionism is the theory of evolution today (let's say Darwinism for short) whereby species are said to adapt and evolve into new species and so forth, and this all started with an original life form. You know the story.
My question is where did the genome come from? How does the genome evolve? Specifically, what is the explanation for how novel genes originated?
So would you say novel genes develop and so spread into a population in the long term creating new species in conjunction with new traits and features that likely confer a selective advantage?
So simple organisms early in the evolutionary tree would have simpler genomes and there'd be a greater genomic complexity for later creatures with more traits?
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I don't want to veer off into every topic of evolution as it's best to define an area as you have here and discuss that on a thread so it can properly addressed without running all over the place. But in short, plenty of people have seen the data or evidence on these things and do not believe they support a Darwinist explanation for evolution. Creationists have their explanations, which are worth looking into. IDers have their's, and others that are not Darwinists but accept common descent have their's. Fossils being found in different layers is interesting but the full view of the fossil record indicates no gradual, species to species evolution, as darwinists propose. Just doesn't.
This is a broad topic on it's own though and would be better served on another thread. Your idea people are just pursuing an agenda though is incorrect.
Note the comment on fossil rarity. A big problem with evos in their science is they don't have good, defined terms. Take the notion that fossils are rare. What does that mean? We have thousands of certain whale fossils so at the family or genus level, it's not rare at all.
Simon39759
Master Poster
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There actually is.
It is of little use, it is basically "evolution on a small scale", the one that is quick and easy to see.
Creationists initially rejected all of the theory of evolution but progressively had to admit a limited version of it, as it was observed all the time.
They then moved the goal-posts, latched on a small arbitrary term and blew up its significance... Somewhat changing its meaning.
In real science, microevolution is small change at the species level. Macroevolution being change above that level. So, by definition, slower to appear.
Of course, both have now been demonstrated and observed. But creationists had, meanwhile, redefine 'microevolution' as: "evolution I can't lie and pretend does not exist" and now still hold the micro/macroevolution bareer as significant.
Of course, it is not, macroevolution is just microevolution on a larger scale, basically, the slow accretion of the tiniest microevolutionary changes...
The idea that microevolution is possible but macroevolution is not makes no sense. It's like saying that a few steps can brings you to the door of our house, but it is absolutely impossible that many ones can bring you to from one house to the other...
The closest hypothesis that creationists use to justify their goalpost shifting brings us to the next quote:
Well, if you mean, the apparition of the first genomes, here is a small video that will give you a quick primer to one of the few hypothesis currently being worked on: Potholer 54.
If you mean the apparition of new genes, during evolutionary time, let's start by correcting a first misunderstanding (I know, you said that " you could argue for the theory of evolution much more than we would be able to", but such misrepresentations falsify such claims).
New species are not defined by new genes. It's an old, out-fashioned view, and science has progressed further than that.
What really matters is how these genes are regulated and expressed, more than what their sequence actually is. A lot of this regulation is provided by other genes, of course, so your vision is not too far of from the truth at first brush.
But it is worth noting, you could probably produce a radically different organism by just altering the regulation of the genes. Indeed most of the genes are common throughout living organisms. This explain why human and chimpanzees can be so quite different, despite sharing more than 99% of their genome and why we, famously, share more than 60% of our genomes with bananas...
That being said, new genes are produced by evolution, quite regularly. As Lukraak mentions, the main mechanisms for this introduction is gene duplicationWP, it is actually very common and it is known that it frees one of the gene to evolve in its own direction, free of direct selection pressure.
This is why we have such huge families of homologs.
Of course, because they are initially so close, homologs often perform similar or parallel functions, but we know that they can sometime be coopted.
For example, the complement and clotting cascades that so impressed Behe, are actually related.
Also, in addition to this mechanism, one must mention horizontal transfer. While probably not as much a source of new genes in metazoans than in simpler organisms, it still does happen as illustrated by the amazing ERVs whose mapping, by the way, is one of the most irrefutable proof of common descent anybody could dream of!
Ps: If we are going to have a detailed conversation about why evolutionary theory is true, we might either start a specific thread in the science sub-section or tack it at the end of the eponymous thread already there...
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lengthy post but didn't really get to the meat of the matter
Let's try to get some clarity here. Did and does the genome evolve via adaptionism aka Darwinism aka evolution aka the rather the theory of evolution?
Please don't dodge the question. Perhaps you've figured out where I am going. Face it head on. Just trying to reduce the conversation to actual data.
Let's try to get some clarity here. Did and does the genome evolve via adaptionism aka Darwinism aka evolution aka the rather the theory of evolution?
Please don't dodge the question. Perhaps you've figured out where I am going. Face it head on. Just trying to reduce the conversation to actual data.
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Does that explain the fear and reluctance to answer my question and discuss the data?
Simon, I am well aware of the things you are discussing. One of the problems with evo talk involves terminology. Label things however you want. Regulatory genes or properties are fine but I am getting at something very basic. Are novel genes or genetic sequences or changes in how they are used or however you want to describe it related to novel morphology or not?
PixyMisa
Persnickety Insect
PixyMisa
Persnickety Insect
What do you mean when you ask about the evolution of the genome?
PixyMisa
Persnickety Insect
Sometimes.
It's simple. Darwinism basically says mutations occur which result in new traits and these are selected if they confer an advantage generally and so new species evolve. The genome evolves along with these new traits.
Isn't that the basics of evolution?
Ladewig
I lost an avatar bet.
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I am willing to listen to other explanations. Do the explanations you are referring to begin with the claim that the world is less than 10,000 years old and that we should expect to see a genetic bottleneck 4500 years ago? Do the explanations include humans and dinosaurs living contemporaneously? Because if they do, then I am prepared to dismiss them immediately as being in conflict with mountains of evidence showing an ancient Earth.
So no matter what the result, it must be evolution, right? totally elastic theory then?