Answering any questions on Evolution

[mark kennedy]

Hi,

I'm an atheist and a genetic/microbiological scientist and because this is a Christian forum I've opened this thread so anyone who wishes to know more about Evolution or my beliefs or why I hold them can ask me questions accordingly.

I would however like a respectful debate, but feel free to counteract anything I say if you disagree. I will try my hardest to remain respectful. Thanks

OK people, ask away.

​

What is the genetic basis for the three-fold expansion of the human brain from that of apes? Source material would be helpful, thanks.

On a side note, perhaps you could answer a question that has bothered me for some time. Where are the chimpanzee ancestors in the fossil record?

 

[bjt2024]

I believe scientists have come up with many drawings to keep their doctrines straight; yes.

Drawings, pictures -- anything to convince us commoners.

Haeckel was notorious for it.

Scientists present facts, data and evidence in charts and graphs which allow clear representation and easier interpretation. A genetic tree allows a person to understand where a clear divergence in speciation occured. Scientists aren't about convincing anyone, we're not a "church" or a "political party". We are about finding out the truth about why things happen. About explaining, the unexplained.

 

[bjt2024]

What is the genetic basis for the three-fold expansion of the human brain from that of apes? Source material would be helpful, thanks.

On a side note, perhaps you could answer a question that has bothered me for some time. Where are the chimpanzee ancestors in the fossil record?

I'm sorry I do not know the exact reason why, you would have to consult a neuroscientist or someone who specilises. However I can presume, that apes which genetically had larger brains were better suited to survive, and as a result these apes lived on to produce offspring with larger brains and this process continued for millions of years. However I am not entirely sure sorry.

The chimpanzee ancestors and the human ancestors will be at some point around 4-6 million years ago, the same species. This is because they diverged into 2 different genera, Homo and Pan. This is often what people call the missing link. There are no fossil records to date, as fossils are extremely hard to find due to natural decay. Scientists use "single-nucleotide polymorphisms" which are single base changes in DNA, to track the differences between different species. For example a species closely related will have fewer SNP's than a species less closely related. The amount of SNP's can be used to calculate roughly the distance between two species genetically and therefore at what point they diverged.

 

[NailsII]

Going backwards, let the dots represent:

• Homo sapiens sapiens
• Homo sapiens idaltu
• Homo rudolfensis
• Homo rhodesiensis
• Homo neanderthalensis
• Homo hiedelbergensis
• Homo habilis
• Homo georgicus
• Homo gautengensis
• Homo floresiensis
• Homo ergaster
• Homo erectus
• Homo cepranensis
• Homo antecessor

I'm not going to believe that there is a line connecting all these dots.

I don't believe there is a single line to join these dots either.
Multiple lines, yes.
The end diagram would look a little like a tree, you might say.
Note - i think that recent evidence would show H. Neanderthalis is more likely to be H. sapiens neanderthalis

What is the genetic basis for the three-fold expansion of the human brain from that of apes? Source material would be helpful, thanks.

Not asking for much then!

On a side note, perhaps you could answer a question that has bothered me for some time. Where are the chimpanzee ancestors in the fossil record?

There are very few, if any, chimpanzee fossils discovered to date.
The most probable reason for this is that they tend to live in areas which make fossilisation almost impossible.
To the best of my knowledge - and I am no geologist, so I could be wrong here - most fossil finds come from amber, volcanic ash and sea/riverbeds.
The reason is simple - the body must be quickly covered to avoid predation and scattering of remains.
Last time I checked, Chimps don't live in areas where this is likely, and they are a little too big to be encased in amber very often.

As has been pointed out, this isn't a problem as we have conclusive genetic evidence which supports the ideas of chimps and humans (as well as bonobos, orangutans and gorillas) sharing a common ancestor.

 

[KhaosTheory]

Going backwards, let the dots represent:

• Homo sapiens sapiens
• Homo sapiens idaltu
• Homo rudolfensis
• Homo rhodesiensis
• Homo neanderthalensis
• Homo hiedelbergensis
• Homo habilis
• Homo georgicus
• Homo gautengensis
• Homo floresiensis
• Homo ergaster
• Homo erectus
• Homo cepranensis
• Homo antecessor

I'm not going to believe that there is a line connecting all these dots.

Ok, what would convince you that these species are related WITHOUT having to connect the dots, hmm?

If we showed you 5,000 different dots, would you be willing to connect them then?

Some lineages are almost complete yet you still claim that there's only a connection if you arbitrarily "connect the dots".

Don't you see the trend in evolution deniers?

When we connect 2 dots, they see another hole,
When we connect 3 dots, they see 2 more holes,
When we connect 4 dots, they see 3 more holes,
When we connect 5 dots, they see 4 more holes, and so on and so on...

How many transitionals do you need before you'll accept common descent? Tell me the number, please!

 

[AV1611VET]

If we showed you 5,000 different dots, would you be willing to connect them then?

No -- and I'll use Ken Hovind's point to explain why.

You can't prove that any one of these 5,000 unconnected dots had a child.

 

[Valkhorn]

No -- and I'll use Ken Hovind's point to explain why.

You can't prove that any one of these 5,000 unconnected dots had a child.

Science doesn't have 'proof'. Proof is for math and alcohol only. Nothing in science is 100% proven and nothing ever can be. That's how we can determine if it's right or wrong, and if it can be wrong, how.

The only people besides mathematicians and brewers who think they have proof are creationists.

Of course 'thinking' and actually having proof are two separate things.

 

[AV1611VET]

Science doesn't have 'proof'.

Bologna -- DNA can prove Joe is Bob's son, thus proving Bob had a son.

 

[NGC 6712]

Bologna -- DNA can prove Joe is Bob's son, thus proving Bob had a son.

That is not an example of science. That is an example of technological use of science.

 

[AV1611VET]

Science doesn't have 'proof'. Proof is for math and alcohol only.

Bologna -- DNA can prove Joe is Bob's son, thus proving Bob had a son.

That is not an example of science. That is an example of technological use of science.

Then I take it adding 3 to 3 to get 6 is an example of arithmetical use of math?

 

[Eldalar]

That is not an example of science. That is an example of technological use of science.

And even then, wasn't there still an uncertainty left? Yes I know, that the current human population on this planet is far too small to make it realistically possible for those tests to produce a false positive, but it is a theoretical possibility isn't it? Also aren't those tests once again based "only" on theories, therefore not making them fit to serve as a final prove?

They are enough for courts etc. but are they really "100% infallible no matter what coincidence"-prove?

 

[NGC 6712]

Then I take it adding 3 to 3 to get 6 is an example of arithmetical use of math?

Not understanding what science is (an inductive logic system) as opposed to say mathematics (a deductive logic system) is not exactly unusual, so you can feel relaxed to be in a group with so many others. Doesn't help this thread any but what the heck.

 

[mark kennedy]

I'm sorry I do not know the exact reason why, you would have to consult a neuroscientist or someone who specilises. However I can presume, that apes which genetically had larger brains were better suited to survive, and as a result these apes lived on to produce offspring with larger brains and this process continued for millions of years. However I am not entirely sure sorry.

Well, you were pretty general in your opening statement and I've read as much as I can find on the subject. Now, a selective advantage would account for the traits being 'selected' but that's an effect. What I am most interested in is how highly conserved genes like brain related genes were altered in the first place.

The chimpanzee ancestors and the human ancestors will be at some point around 4-6 million years ago, the same species. This is because they diverged into 2 different genera, Homo and Pan. This is often what people call the missing link. There are no fossil records to date, as fossils are extremely hard to find due to natural decay. Scientists use "single-nucleotide polymorphisms" which are single base changes in DNA, to track the differences between different species. For example a species closely related will have fewer SNP's than a species less closely related. The amount of SNP's can be used to calculate roughly the distance between two species genetically and therefore at what point they diverged.

Sounds pretty reasonable so far. There are about 35 million SNPs that diverge between Chimpanzees and humans, what would you say the divergence based on indels, or gaps, would be? Disregarding the chromosomal rearrangements for the moment, what would you expect the level of divergence to be as measured in base pairs?

 

[Naraoia]

Hi,

I'm an atheist and a genetic/microbiological scientist and because this is a Christian forum I've opened this thread so anyone who wishes to know more about Evolution or my beliefs or why I hold them can ask me questions accordingly.

I would however like a respectful debate, but feel free to counteract anything I say if you disagree. I will try my hardest to remain respectful. Thanks

OK people, ask away.

Hello! Another biologist, yay!

With the modern understanding of genetics, and how certain areas of genes, for example the homeobox, code for the regulation of the morphological appearance of an organism. Therefore the appearance differences of two different organisms can be followed across to certain differences in their genomes. This means that the taxonomy system of Linnaeus can be mostly applied a system of genetic catergorisation of life.

I think the more important point when it comes to common descent is that genes also independently point to the same classification as phenotypic traits do. While some sequence changes might have morphological correlates, there is often no obvious causal relationship between sequence and morphology*. Why would, say, ribosomal RNA or cytochrome c, which have little to do with generating morphology, point to the same tree of life as morphology unless there really is a true tree of life?

*Glad you brought up homeoboxes - they make a perfect example. Hox factors and their relatives can work rather well in very distant relatives, despite differing in most of their protein sequence. You express mouse Pax6 in a fly, it'll grow fly eyes. You express a chicken Hox1 in a labial-deficient fly, you'll get flies, not some strange fly-mouse mix. Though I have to say Hox sequences make for rubbish phylogenetic data. Too little conservation, and at the same time, too much

What is the genetic basis for the three-fold expansion of the human brain from that of apes? Source material would be helpful, thanks.

Oh, by the way, I found this languishing unread in my collection:

PLoS Biology: Accelerated Recruitment of New Brain Development Genes into the Human Genome

(It's PLoS, so it's free)

On a side note, perhaps you could answer a question that has bothered me for some time. Where are the chimpanzee ancestors in the fossil record?

I'm sure it also bothers palaeontologists. Speaking of, has anyone ever plugged things like Toumai and Orrorin into a proper cladistic analysis? (Do they even have enough material for that?) That would be quite interesting, considering how uncertain the placement of those two seems to be from pop-sci sources. Who knows, one of these beasts might turn out to be the chimp ancestor you're looking for.

 

[mark kennedy]

Oh, by the way, I found this languishing unread in my collection:

PLoS Biology: Accelerated Recruitment of New Brain Development Genes into the Human Genome

(It's PLoS, so it's free)

I recognized a couple of the researchers from other papers. It's interesting how transcriptomes are a common theme. Thanks for the link, an interesting paper.

I'm sure it also bothers palaeontologists. Speaking of, has anyone ever plugged things like Toumai and Orrorin into a proper cladistic analysis? (Do they even have enough material for that?) That would be quite interesting, considering how uncertain the placement of those two seems to be from pop-sci sources. Who knows, one of these beasts might turn out to be the chimp ancestor you're looking for.

To date, I have yet to see a paleontologist successfully identify a chimpanzee ancestor under 25 million years old. I found that very odd since our ancestors would have been contemporary with then in Africa for at least 2 million years before spanning out in a massive migration of hominids. Somehow the Orangutans made it to Asia and a slight variation of chimpanzees made it to the Congo in equatorial Africa.

Many of the fossils bear a strong resemblance to Chimpanzee morphology, especially the Taung Child. For many years it was considered a Chimpanzee because of the size of the skull and it was even small for a Chimpanzee.

At any rate, always interesting reading your posts.

Grace and peace,
Mark

 

[Naraoia]

I recognized a couple of the researchers from other papers. It's interesting how transcriptomes are a common theme. Thanks for the link, an interesting paper.

Next-generation sequencing makes people go crazy. Imagine what happens when third-gen technology becomes widely available...

To date, I have yet to see a paleontologist successfully identify a chimpanzee ancestor under 25 million years old.

I thought there were a bunch of teeth or other fragmentary remains interpreted as such that post-dated the human-chimp split.

And again, I don't think anyone actually did a rigorous phylogenetic analysis on some of the earliest ?hominin remains. It's fairly commonplace to do with newly described dinosaurs, which are one of my other random side interests, but somehow palaeoanthropologists don't seem to bother. And then you get hypotheses flying around without proper testing.

I found that very odd since our ancestors would have been contemporary with then in Africa for at least 2 million years before spanning out in a massive migration of hominids. Somehow the Orangutans made it to Asia and a slight variation of chimpanzees made it to the Congo in equatorial Africa.

Maybe we should look for chimp fossils IN the Congo

Many of the fossils bear a strong resemblance to Chimpanzee morphology, especially the Taung Child. For many years it was considered a Chimpanzee because of the size of the skull and it was even small for a Chimpanzee.

Well, it is immature

I think the chimp-like look may not be specifically chimp-like as much as typical ape-like. Modern human skulls are exceptional among living apes in that they never really "grow up", so a small-brained ape skull that has begun to exhibit adult characteristics is going to look more like (adult) chimps than humans by default. This skull is not so "chimp-like":

... even though it is a chimp skull.

As for brain size, well, there's a pretty 19th century preconception for you. People decided that a human ancestor must be big-brained based on... what exactly? At the time, knowledge of human ancestors was pretty much limited to Neandertals, fragments of Java man, and the Piltdown hoax.

 

[cupid dave]

Hi,

I'm an atheist and a genetic/microbiological scientist and because this is a Christian forum I've opened this thread so anyone who wishes to know more about Evolution or my beliefs or why I hold them can ask me questions accordingly.

I would however like a respectful debate, but feel free to counteract anything I say if you disagree. I will try my hardest to remain respectful. Thanks

OK people, ask away.

​

When you say you are an atheists does that also mean you deny that the bible is dead right in Genesis?


It is clear that the Universe DID have a beginning, 13.5 billion years ago.
(Gen 1:1)

There were seven long Cosmic "days" since that Big Bang, which we call the seven cosmic/geological Eras.

A Cosmic Dark Age did precede that advent of let there be light to flood the cosmos.
(Gen 1:3-5)

There was one ocean, once, where all the waters had been collected together.
(Gen 1:9)

Pangea/Rodinia did actually confirm that the dry land appeared surrounded totally by water.
(Gen 1:10)

The Plant kingdom did establish itself before the Animal kingdom.
(Gen 1:11)

Man WAS the last step in the evolution of Dominant Life on earth.
(Gen 1:27)

 

[cupid dave]

As for brain size, well, there's a pretty 19th century preconception for you. People decided that a human ancestor must be big-brained based on... what exactly? At the time, knowledge of human ancestors was pretty much limited to Neandertals, fragments of Java man, and the Piltdown hoax.

Right...

The issue concerns the single Act-of-God wherein the 24 Chromosomes found in all Apes mutated in one group of Apes, (Adamites).
Two chromosome fused together, and thereafter our species appeared 7 million years and went through 22 evolutionary steps defined by the 22 now extinct species of Humans in our ascent.

 

[Huram Abi]

You don't have to be an atheist to know that all those claims are dead wrong, Cupid.

 

[CabVet]

What evidence?

I'm talking about a line linking those dots.

They are called 'missing links.'

You want me to accept them as missing? is that what you expect me to do?

In my opinion, each one of those dots could have been a productive member of society at one time; kissing his wife and kids 'goodbye' and going off to work; until they were struck down by what the Bible calls a 'wonderful disease.'

There is no line linking these either:

I guess you think dog breeds don't come from wolves either.