The case for Evolution.

Dades

dlofnep wrote: »

Like I said - I've no problems with questions, so long as they are intellectually honest. Something certain posters are not capable of doing. Perhaps if a moderator could remove all posters that are not presenting evidence for evolution, or discussing evolution (including this post) - It will make the thread a lot easier to read.

As alluded to here, undercover-creationists are not welcome. And rest assured they are pretty easy to spot.

Will try to avoid lockage and just use jackbooted censorship instead.

dlofnep

Also worth looking at is why there is a lack of native species on Oceanic Islands. It's important to learn the distinction between Continental Islands and Oceanic Islands, to understand why this supports Evolution.

Oceanic Islands are relatively new Islands, that sprung up (typically from volcanic activity) and were never a part of a continent. Continental islands would have been part of a continent at one point in time, but have since become detached through a variety of means (Rising seas, ice caps melting, etc). They still rest on the continental shelf however.

When looking at the life that exists on the different island types, biologists noticed that the only life that existed in Oceanic islands, were species that had the ability to migrate there (swim, fly, etc..) and originated from near-by land-masses.. Continental islands however, have a vast array of native species, because they have existed for a much longer period of time - and such, have had the the time-span required to accommodate for mass speciation by natural selection.

Now that's not to say that Evolution does not occur on Oceanic islands, but that when comparing two islands of comparable size, habitat and climate - the one with a continental origin varies drastically than the Oceanic island.

Question for the theist: If God created the Earth - then why would he create two islands with similar climates, size and habitats - but provide a much wider array of species on the continental island?

dlofnep

Evolution over very short periods of time.

While speciation can take a considerable length of time, up to millions of years - Evolution itself of a species can be visible within a dozen or two generations. One experiment performed by John Endler examined the role that spots play in the survival of guppies.

The experiment setup artifical ponds for the Guppies, with different types and coarseness of gravel. Each pond had a predatory fish present, to pressure selection of the fish.



Over the course of 15 generations, the fish in each pond adapted their spots to reflect the gravel in their respective ponds. While the Guppies that were put in each pond were originally the exact same, by the time 15 generations passed - their appearance was greatly altered. The results were clear cut proof of evolution in action.



Good outline of the experiment here for anyone who wants a read: http://evolution.berkeley.edu/evosite/evo101/IVB1bInthelab.shtml

Galvasean

What I found most interesting in the guppy experiment is that ironically in the absence of a predator the guppies who stood out from their surroundings (ie: the ones with bad camouflage) were sexually selected and went on to dominate.

Oranage2

There's no doubt species evolve and even take a look at our own species and how the different races have different variations.


But i don't quite get how we evolved from chimps. Chimps are a thriving species and so are humans but how come there aren't and species inbetween or even any evidence of the 'missing link'. Maybe somebody could point me in the right direction, very interesting op.

dlofnep

Oranage2 wrote: »

There's no doubt species evolve and even take a look at our own species and how the different races have different variations.


But i don't quite get how we evolved from chimps. Chimps are a thriving species and so are humans but how come there aren't and species inbetween or even any evidence of the 'missing link'. Maybe somebody could point me in the right direction, very interesting op.

That's because we didn't evolve from chimps. Humans and chimps share a common ancestor which lived about 7 million years ago.

RichieC

Oranage2 wrote: »

There's no doubt species evolve and even take a look at our own species and how the different races have different variations.

dlofnep

As for the missing link canard, there are mass amounts of 'links' going back through a number of different species. The Homo genus alone has about a dozen members. Then we have a handful more within the Australopithecus family.

The 'missing link' might have been a valid question when Darwin was alive, but since then we have found 1000's of fossils documenting the evolution of apes, including the homo genus.

Galvasean

Oranage2 wrote: »

There's no doubt species evolve and even take a look at our own species and how the different races have different variations.


But i don't quite get how we evolved from chimps. Chimps are a thriving species and so are humans but how come there aren't and species inbetween or even any evidence of the 'missing link'. Maybe somebody could point me in the right direction, very interesting op.

For starters it's worth noting that humans did not evolve from chimps and no one in evolutionary biology claims this. It is however a somewhat common misconception, in that when people hear that 'humans evolved from' they assume it means 'humans evolved from currently living apes', which is incorrect. The last common ancestor that humans and chimps share is believed to have lived some 7 million years ago. You can delve more into it here:
http://en.wikipedia.org/wiki/Chimpanzee-human_last_common_ancestor
and also here:
http://en.wikipedia.org/wiki/Human_evolution#Divergence_of_the_human_lineage_from_other_Great_Apes

The term 'missing link' is also somewhat misleading and is generally not used among the scientific community, but unfortunately very popular among pop-science magazines and tabloids for the sake of sensationalism and selling magazines/newspapers.
There have been several of these so called 'missing link' apes found which show a transition from more primitive ape to man over time.
Ardipithecus, which lived over 4 million years ago, appears to be one such ape:
http://en.wikipedia.org/wiki/Ardipithecus
Australopithecus, which lived at a later date (around 3 million years ago) shows more human features than 'Ardi':
http://en.wikipedia.org/wiki/Australopithecus#Evolutionary_role
Without going into too much detail you can see branches of prehistoric apes becoming more human like the closer we come to modern times.

I would strongly recommend having a read through this page:
http://en.wikipedia.org/wiki/Human_evolution#
and then returning here with any follow up questions (as some of the links I've posted can be a bit on the technical side).

darjeeling

Oranage2 wrote: »

But i don't quite get how we evolved from chimps.

We didn't. Chimps are like very distant cousins. We didn't evolve from our cousins, but we share a common ancestor with them.

Oranage2 wrote: »

Chimps are a thriving species and so are humans but how come there aren't and species inbetween

This is like asking why there is no language in between Italian and Spanish, given that they have a common root. Why should there be?

Oranage2 wrote: »

or even any evidence of the 'missing link'.

What precisely are you thinking of when you use the phrase 'the missing link'? There are plenty of fossils of hominins that have a number of ancestral characteristics shared with the other great apes, and other derived characteristics seen today only in humans. This is consistent with what we would expect if humans had evolved from a common ancestor shared with the other great apes.

Add comparison of genome sequences into the mix (and we now have genomes for all the great apes) and the evolutionary closeness between human, chimp, gorilla and orang-utan is clear. The family tree we obtain is unambiguous, and replicates what we see from anatomical measurements.

sephir0th

Oranage2 wrote: »

Chimps are a thriving species and so are humans but how come there aren't and species inbetween.

This is quite an interesting question if you look at it in terms of what is alive today. Galvasean has pointed out evidence for transitional species from the common ancestor to modern humans. Obviously, all these species are now extinct.

I guess the tangential question I would pose is, presumably some of these species had adapted to a degree of intelligence higher than the modern chimp, was it just a case that the selection pressures were harder on the human line than the chimp line?

Galvasean

sephir0th wrote: »

This is quite an interesting question if you look at it in terms of what is alive today. Galvasean has pointed out evidence for transitional species from the common ancestor to modern humans. Obviously, all these species are now extinct.

I guess the tangential question I would pose is, presumably some of these species had adapted to a degree of intelligence higher than the modern chimp, was it just a case that the selection pressures were harder on the human line than the chimp line?

Intelligence isn't the be all and end all of evolution though. Depending on the ecological niche sometimes it is better to be agile, strong, what have you than very intelligent. Chimps live in places full of trees and have evolved great agility to take advantage of such.
Hypothetical example:
Chimp 1 is more agile but not as clever as chimp 2. One day Chimp 2's lack of agility results in him falling from a tree and dying, failing to send on his genes to the next generation. His intelligent genes are lost to the gene pool while Chimp 1's agile genes remain.
I know it's a very basic analogy, but I hope it answers your question (that is, if I am reading your question correctly in the first place).

darjeeling

sephir0th wrote: »

This is quite an interesting question if you look at it in terms of what is alive today. Galvasean has pointed out evidence for transitional species from the common ancestor to modern humans. Obviously, all these species are now extinct.

I guess the tangential question I would pose is, presumably some of these species had adapted to a degree of intelligence higher than the modern chimp, was it just a case that the selection pressures were harder on the human line than the chimp line?

Selection pressures were different, I think we can say. Proto-chimps seem to have remained in more forested environments, whereas proto-humans moved into more savannah-like environments. Incidentally, this difference in habitat helps explain why chimp ancestor fossils are so scarce (mostly we just have fossil teeth).

Changes in diet may help account for the increase in human brain size and complexity too. Actually I was just reading this in the Guardian this morning:
How many neurons make a human brain?
From the article, our brains have around three times the number of neurons seen in a gorilla. They also use a remarkably large amount of our energy intake (20-25% is quoted), so it may have taken a switch in the foods our ancestors were eating, and the way they prepared them, to allow for the dramatic expansion in the brain.

Galvasean

darjeeling wrote: »

Changes in diet may help account for the increase in human brain size and complexity too. Actually I was just reading this in the Guardian this morning:
How many neurons make a human brain?
From the article, our brains have around three times the number of neurons seen in a gorilla. They also use a remarkably large amount of our energy intake (20-25% is quoted), so it may have taken a switch in the foods our ancestors were eating, and the way they prepared them, to allow for the dramatic expansion in the brain.

If I remember correctly the move to savannahs led to a more protein based diet (meat, nuts etc.) which is very helpful for producing big brains. Apes in forests rely more heavily on abundant fruit and vegetation.

RichieC

Galvasean wrote: »

If I remember correctly the move to savannahs led to a more protein based diet (meat, nuts etc.) which is very helpful for producing big brains. Apes in forests rely more heavily on abundant fruit and vegetation.

Yea, in a documentary I watched last night they cited a change to shellfish as catalyst for even further frontal lobe development.

sephir0th

Galvasean wrote: »

Intelligence isn't the be all and end all of evolution though.

I understand that increased intelligence isn't necessarily the marker of a successful adaptation. But a chimp with all the flexibility of another chimp except with some extra intelligence, I thought would have been favoured. Perhaps the selection pressure, as you say, in forested environments just wasn't there along with the correct food protein sources.

darjeeling wrote: »

Changes in diet may help account for the increase in human brain size and complexity too. Actually I was just reading this in the Guardian this morning:

That would explain a lot. Presumably both lines would have adapted towards larger brains at some point right? A larger brain doesn't necessarily have to come at a cost to flexibility etc. or does it? Food sources may explain it.

Solair

You're basically evolutionary cousins with any living, modern species of animal (and very very distant cousin to insects and plants etc)

we all evolved from ancient, organisms.

in fact, you've even got DNA in common with a banana, or even bacteria never mind apes if you go back to absolutely the start of evolution.

Oranage2

darjeeling wrote: »

What precisely are you thinking of when you use the phrase 'the missing link'?

To be honest, I was expecting cute little monkey men running around.

Galvasean wrote: »

For starters it's worth noting that humans did not evolve from chimps and no one in evolutionary biology claims this. It is however a somewhat common misconception, in that when people hear that 'humans evolved from' they assume it means 'humans evolved from currently living apes', which is incorrect. The last common ancestor that humans and chimps share is believed to have lived some 7 million years ago. You can delve more into it here:
http://en.wikipedia.org/wiki/Chimpanzee-human_last_common_ancestor
and also here:
http://en.wikipedia.org/wiki/Human_evolution#Divergence_of_the_human_lineage_from_other_Great_Apes

The term 'missing link' is also somewhat misleading and is generally not used among the scientific community, but unfortunately very popular among pop-science magazines and tabloids for the sake of sensationalism and selling magazines/newspapers.
There have been several of these so called 'missing link' apes found which show a transition from more primitive ape to man over time.
Ardipithecus, which lived over 4 million years ago, appears to be one such ape:
http://en.wikipedia.org/wiki/Ardipithecus
Australopithecus, which lived at a later date (around 3 million years ago) shows more human features than 'Ardi':
http://en.wikipedia.org/wiki/Australopithecus#Evolutionary_role
Without going into too much detail you can see branches of prehistoric apes becoming more human like the closer we come to modern times.

I would strongly recommend having a read through this page:
http://en.wikipedia.org/wiki/Human_evolution#
and then returning here with any follow up questions (as some of the links I've posted can be a bit on the technical side).

Interesting indeed, though I'm not convinced we or the other species have all evolved from a single celled organism. After doing a bit of looking up it seems that there's not much fossil evidence that we have evolved from any sort of chimp man. Even the great pioneer of evolution Charles Darwin doubts his theory

"Lastly, looking not to any one time, but to all time, if my theory be true, numberless intermediate varieties, linking closely together all the species of the same group, must assuredly have existed. But, as by this theory, innumerable transitional forms must have existed, why do we not find them embedded in countless numbers in the crust of the earth?"

Again I do believe that species like humans can evolve through genetic selection, I just dont think there's enough evidence to believe we all evolved from the same ancient organisms.

oldrnwisr

Oranage2 wrote: »

Interesting indeed, though I'm not convinced we or the other species have all evolved from a single celled organism. After doing a bit of looking up it seems that there's not much fossil evidence that we have evolved from any sort of chimp man.

We don't need fossil records to provide evidence for common descent. There are many overlapping fields which biologists use to provide an overall picture of how evolution has occurred.

Genetics is one of those fields. Some time ago, someone noticed that while we only have 23 chromosomes our cousins in the primate family have 24. So if we share a common descent with other primates, then at some point, two of the ancestral ape chromosomes must have become fused together. This is what we find to be the case.



We were able to verify this in several different ways. Firstly, the banding pattern on human chromosome 2 matches that on chimp chromosomes 12 and 13 when lined up. Secondly, the end of a chromosome is marked by a sequence called the telomere. When we look at the telomeres of the chimp chromosomes we find that the same sequences are found in the centre of human chromosome 2, indicating fusion. If you want I can post some of the research that demonstrates this in more detail, or alternatively I can post some of the other genetic evidence for common descent such as endogenuous retroviruses (ERVs) or bornavirus.

Oranage2 wrote: »

Even the great pioneer of evolution Charles Darwin doubts his theory

Please don't do that. We were having such a nice discussion on evolution. I swear if I see a quote about the eye I'm going to go postal!

sephir0th

Oranage2 wrote: »

I just dont think there's enough evidence to believe we all evolved from the same ancient organisms.

How hard have you looked?

Here's a start:
http://www.talkorigins.org/faqs/comdesc/

Sarky

Innumerable transitional fossils HAVE been found though. Fossils are pretty rare due to the circumstances required for their creation. Taking that into account we've discovered a huge number of them, easily more than enough to cement evolution as the way things happened.

Darwin was perfectly right to be skeptical at the time, but a shedload of evidence has been found since then. If he were alive today he'd agree that he was right about evolution.

Sarky

Ooh, moar genetics plz. I never studied non-bacterial genetics in any great detail, I wouldn't mind seeing some.

darjeeling

Oranage2 wrote: »

To be honest, I was expecting cute little monkey men running around.

Well, ok, but the point is that the phrase 'missing link' has gotten into the culture without really being defined. I think that we've found a lot of fossils with a pattern of features telling us that humans evolved from earlier apes. These fossils have some features that are shared with the other apes but not with humans, and other features shared only with humans. They seem to fit what many people might consider missing links.

Oranage2 wrote: »

After doing a bit of looking up it seems that there's not much fossil evidence that we have evolved from any sort of chimp man. Even the great pioneer of evolution Charles Darwin doubts his theory

Darwin didn't have most of the evidence we have now, and was inclined at times to moderate what he thought, and initially wrote, for expedient reasons. However, he did predict - on the basis of human and African ape similarity - that we'd all have a common ancestor in Africa:

Darwin, The Ascent of Man wrote:

[SIZE=-1][SIZE=-1]"It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; as these two species are now man’s closest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere."[/SIZE][/SIZE]

As we now know, the first evidence for the presence of humans and chimps is seen in the same area of the world. Humans and chimps have very similar genomes, such that (as posted by others above) you can find lots of chance mutations that are present in both humans and chimps, but not in the more distant gorillas and orang-utans. This is what you would expect to see if humans and chimps had evolved from a common ancestor that was more recent than the common ancestor with the other apes.

Going much further back in time, no apes are seen in the fossil record before the Miocene, around 23 million years ago. No primates are seen before ~65 million years ago at the earliest. No mammals are seen before around 220 million years ago, no land vertebrates before around 370 million years ago, and so on. This pattern of new forms of animal appearing and then diversifying over time is consistent with the current evolutionary model.

Oranage2 wrote: »

I'm not convinced we or the other species have all evolved from a single celled organism. [...] Again I do believe that species like humans can evolve through genetic selection, I just dont think there's enough evidence to believe we all evolved from the same ancient organisms.

When it comes to asking if all of life has a common ancestor, we can look again at the level of DNA. We find that all organisms use the same genetic code (with a couple of minor differences), the same set of 20 amino acids for making proteins, and that all have a set of core genes for protein synthesis and some other fundamental elements of life. This is, again, consistent with life having a common ancestor.

Sarky

I understand DNA from mitochondria (little cellular organs that have a load of useful functions but most importantly generate the chemical adenosine triphosphate, which pretty much every animal/plant cell uses for fuel) has been particularly useful with regards to looking at human evolution, although I'm not very well up on the specifics. I'd imagine that mitochondrial DNA is subject to fewer changes over time as it's essential to a functioning cell, so you can look further back into its history before the changes become too fuzzy to infer anything. Am I close?

dlofnep

Oranage2 wrote: »

Interesting indeed, though I'm not convinced we or the other species have all evolved from a single celled organism. After doing a bit of looking up it seems that there's not much fossil evidence that we have evolved from any sort of chimp man. Even the great pioneer of evolution Charles Darwin doubts his theory

Ok, I have to nip this in the bud before it gets out of control. A few things. Firstly - a few posts back, you were under the impression that Evolutionary biologists claimed that humans evolved from chimps. This indicates to me, that your understanding of Evolution is extremely limited.

So with that being said - You make the claim that you don't see much evidence in support of it, but you clearly have not researched Evolution in the detail that it requires to validate such a statement.

What Charles Darwin stated on Evolution is not relevant. Darwin lived in the 1800's, when there was a very poor fossil record. His theories based on observation were later validated as the fossil record grew stronger, and we came to understand DNA. While for his time, Darwin's theories were ground-breaking - we have since then built upon them - with much stronger evidence.

It would be like citing the work of an astronomer from the 1800's, over NASA of today with their high-powered telescopes, rockets, and planetary rovers. To put simply - the Evolutionary biologists of 2012 are the people that you should be looking at, and not Darwin - who was still only getting to grips with the idea of evolution.

Since Darwin died - we have found a mass amount of transitional fossils. A partial fossil of Homo Erectus was found 10 years after Darwin's death, with Homo heidelbergensis about another 15 years after that. Neanderthal was the only fossil around when he was alive, which alone would not have given an overall view on the evolution of humans. In total, we have found the following species (in order by date found):

Homo neanderthalensis (1829), Homo erectus (1891), Homo heidelbergensis (1907), Australopithecus africanus (1924), Homo habilis (1949), Homo rhodesiensis (1953), Homo rudolfensis (1971), Australopithecus afarensis (1973), Homo gautengensis (1976), Homo sapiens idaltu (1997), Homo floresiensis (2003)

There's a few other species I have left out to save time, and obviously as time progressed more and more fossils have been found for each species, some more impressive than others. The point is, that all of these except one were found after the death of Charles Darwin. So to try and cite Darwin's lack of evidence while he lived as some sort of flaw in the theory of Evolution itself, or the evolution of humans is a logical fallacy.

Oranage2 wrote: »

Again I do believe that species like humans can evolve through genetic selection, I just dont think there's enough evidence to believe we all evolved from the same ancient organisms.

DNA confirms that we did. The fossil record gives is a glance at certain time periods, where we can see important evolutionary transitions - such as lobe-finned fish to tetrapods, reptiles to mammals, dinosaurs to birds, early primates up to modern primates, etc... This is all immensely powerful evidence to support a shared ancestor.

Solair

Of any area of science, evolutionary biology has to be one of the easier bits to demonstrate that it's clearly a very accurate and correct theory. There's heaps and heaps and HEAPS of evidence all around you. You can run experiments in the lab to prove it works with simple single-celled organisms with very short generational cycles etc etc.

I can't see how this is possibly controversial (and it's not in Ireland! This tends to be a debate that's had in the USA more than anywhere else in the 'developed world')

Where as perhaps some areas of highly theoretical astrophysics are a bit more tricky to prove!

Sarky

That's why it's called theoretical.

That's what theories do though. They don't prove things, they pretty much state "If this explanation is correct, then you should see it in XYZ".

That's what Darwin did. He said if evolution is right, you'll see transitional fossils. So people went out looking for transitional fossils and hey! They found loads across tonnes of species.

Most of the scientific process is about figuring out how to make a reliable test, figuring out what to look for, how to measure it and how to take into account all the factors that could screw with the measurement. People are still trying to invent ways to test some of Einstein's predictions on relativity, although everything they're managed to test so far has validated his theories pretty well.

And of course there's the peer-review, a real trial by fire as a load of scientists at least as knowledgeable as you tear into your work to see if it still holds up or if you missed anything. They're not kind, but they're thorough, and if they can't find a way to disprove your work, it's decent evidence that you might be onto something. The actual discovery is only an added bonus at the end of all that.


Science- It works, bitches.

Galvasean

sephir0th wrote: »

That would explain a lot. Presumably both lines would have adapted towards larger brains at some point right? A larger brain doesn't necessarily have to come at a cost to flexibility etc. or does it? Food sources may explain it.

A larger brain doesn't necessarily come at a cost of agility, but both require extra energy to maintain. As you allude to, they probably didn't have access to all of the nutrients required (in large enough quantities) to maintain both.

darjeeling wrote: »

Going much further back in time, no apes are seen in the fossil record before the Miocene, around 23 million years ago. No primates are seen before ~65 million years ago at the earliest.

FWIW, the first primates are believed to have shown up around 85 million years ago, based on molecular clock studies (something anyone with an interest in learning about modern evolutionary theory should seriously consider checking out).

darjeeling

Sarky wrote: »

I understand DNA from mitochondria (little cellular organs that have a load of useful functions but most importantly generate the chemical adenosine triphosphate, which pretty much every animal/plant cell uses for fuel) has been particularly useful with regards to looking at human evolution, although I'm not very well up on the specifics. I'd imagine that mitochondrial DNA is subject to fewer changes over time as it's essential to a functioning cell, so you can look further back into its history before the changes become too fuzzy to infer anything. Am I close?

It has its own little circular genome, which has shrunk down the evolutionary ages as more of its genes have transferred into the nucleus (the process is a a one-way street). The genes it retains code for the mitochondrial ribosome and the electron transport chain, used to produce energy. From memory, if you look at sufficiently divergent taxa, you can find different sets of genes retained in the mt genome.

mtDNA has useful features that allow it to be used for different scales of evolutionary analyses. It comes down the female line, so it doesn't recombine. It has regions under weak selective constraint (faster evolving) and regions under strong constraint, so it can be used to look over different timescales.

In humans, all people alive today have mtDNA that coalesces to a single ancestor around 170,000 years ago (the famous 'Mitochondrial Eve'). The diversity we see today has all arisen since mtDNA Eve lived, and has been used to trace pre-historic human movements around the world. We find that the greatest diversity is in Africa, and that the first modern human migrants leaving Africa carried within them only a part of that diversity. Once established around the world, new variations arose that can distinguish between people whose ancestors had settled in different regions.

When we got the first Neanderthal mtDNA sequences, they lay outside the human mtDNA family tree, as did the new Denisovan mtDNA genome. However, when trees were made using chimp mtDNA as an outgroup, the human and Neanderthal appeared as the closest relatives, with Denisovan more distant, and chimp the least related to any other.

For constructing overall family trees of life, I think that one of the nuclear ribosomal RNA genes (18S rRNA) from eukaryotes was initially used to compare with the corresponding prokaryotic gene (16S rRNA) URL="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC432104/?page=1"]link[/URL. Other key genes most essential to life have also been used since. These genes are so fundamental that they change very slowly, allowing comparisons between the most distant living organisms.

.

oldrnwisr

Sarky wrote: »

Ooh, moar genetics plz. I never studied non-bacterial genetics in any great detail, I wouldn't mind seeing some.

Ask, and ye shall receive.

OK, leading off from the example of the chromosome fusion in human chrosome 2, one of the more recent examples of common descent based on chromsomal analysis is the study of a neocentromere on human chromosome 6. An ancient chromosome at some point about 17 million years ago moved position and was rendered functionless. This change is shared in primates and the various mutations in the centromere sequence allowed the chromosome to be dated to between 17 and 23 million years ago. The image below is a simplified version of the graphic presented in the paper which shows how the analysis from each primate allowed the phylogeny of the original centromere to be determined.



Original paper:

Evolutionary descent of a human chromosome 6 neocentromere: A jump back to 17 million years ago

Some primers on neocentromeres:

Neocentromeres: New Insights into Centromere Structure, Disease Development, and Karyotype Evolution

Chromosomal dynamics of human centromere function

Centromere repositioning in mammals


In keeping with Sarky's recent posts on the "other" thread, one of the more elegant pieces of evidence for common descent is the presence of endogenuous retrovirus insertions in modern primates. Basically, ERVs inject a random piece of their DNA into the host genome which then gets passed on. Most of the time these insertions are functionless, causing no harm to the host animal. There is a growing body of research, however, which suggests that some human ERVs (hERVs) play a role in the development of certain autoimmune diseases such as MS.
Genetic sequencing has found that all primates share quite a few identical or near-identical ERV sequences. The image below shows where different ERV sequences have been inserted over time, showing up in all subsequent branches:




Primer on ERVs:

Endogenuous retrovirus

Research papers:

Differences in HERV-K LTR insertions in orthologous loci of humans and great apes

Genomewide screening for fusogenic human endogenous retrovirus envelopes identifies syncytin 2, a gene conserved on primate evolution

Human Endogenous Retrovirus Family HERV-K(HML-5): Status, Evolution, and Reconstruction of an Ancient Betaretrovirus in the Human Genome


More genetics later when I have some more time.

Oh and before I forget, again, big thanks to dlofnep for starting this thread and for an awesome OP.