Scientists home in on origin of human, chimpanzee facial differences

chimpanzees
Common Chimpanzee in the Leipzig Zoo. Credit: Thomas Lersch/Wikipedia

The face of a chimpanzee is decidedly different from that of a human, despite the fact that the apes are our nearest relative in the primate tree. Now researchers at the Stanford University School of Medicine have begun to pinpoint how those structural differences could arise in two species with nearly identical genetic backgrounds.

The key lies in how genes involved in facial development and facial diversity are regulated—how much, when and where the genes are expressed— rather than dissimilarities among the genes themselves. In particular, the researchers found that chimps and humans express different levels of proteins known to control facial development, including some involved in jaw and nose length and .

"We are trying to understand the regulatory changes in our DNA that occurred during recent evolution and make us different from the great apes," said Joanna Wysocka, PhD, associate professor of developmental biology and of chemical and systems biology. "In particular, we are interested in craniofacial structures, which have undergone a number of adaptations in head shape, eye placement and facial structure that allow us to house larger brains, walk upright and even use our larynx for complex speech."

The researchers coined the term "cellular anthropology" to explain how some steps of early primate development can be mimicked in a dish, and thus used to study gene-expression changes that can shed light on our recent evolutionary past.

A study describing the research will be published online Sept. 10 in Cell. Graduate student Sara Prescott is the lead author. Wysocka and senior research scientist Tomasz Swigut, PhD, share senior authorship of the study.

The role of enhancer regions

For their comparison, the researchers focused on areas of DNA known as enhancer regions in human and chimpanzee genomes. These regions contain chemical tags and proteins bound to the DNA that control when, where and how nearby genes are expressed. Prescott and her colleagues wondered whether differences in the way proteins bind to these enhancer regions during development could explain morphological differences between humans and chimpanzees.

"We wanted to look at how the activity of these enhancer regions may have changed during recent evolution," said Wysocka. "Many recent studies have shown that changes in the DNA sequences of enhancers may mediate morphological differences among species."

To conduct the study, however, Prescott and her colleagues had to obtain a specialized type of cell present only in very early primate development. The cells, called cranial neural , originate in humans within about five to six weeks after conception. Although they first appear along what eventually becomes the spinal cord, the neural crest cells then migrate over time to affect facial morphology and differentiate into bone, cartilage and connective tissue of the head, and face.

"These cells are unique," said Prescott. "If we want to understand what makes human and chimp faces different, we have to look to the source—to the cell types responsible for making these early patterning decisions. If we were to look later in development or in adult tissues, we would see differences between the species but they will tell us little about how those differences were created during embryogenesis. But accessing early cell types like neural crest cells can be quite difficult, especially when studying primates."

To obtain this elusive cell type, the researchers used induced , or iPS cells, made from chimpanzees. IPS cells, which are made from easy-to-obtain skin or blood samples, can be coaxed to become other tissues. Although iPS cells from humans have been well-studied, they've only recently been made from chimpanzees in the laboratory of Fred Gage, PhD, a professor of genetics at the Salk Institute for Biological Studies and a co-author of the study.

Prescott and her colleagues coaxed human and chimpanzee iPS cells to become cranial cells by growing them in the laboratory under a specific set of conditions. They then examined enhancer regions throughout the genome, looking for those that were not just active and therefore likely to be involved in craniofacial development, but also those whose patterns or degrees of activity seemed to vary between human and chimpanzee cells.

"Of course, humans and chimps are very closely related," said Wysocka. "Most of the regulatory elements are the same between the two species. But we did find some differences. In particular, we found about 1,000 enhancer regions that are what we termed species-biased, meaning they are more active in one species or the other. Interestingly, many of the genes with species-biased enhancers and expression have been previously shown to be important in craniofacial development or associated with normal intrahuman facial variation."

Snout length, shape and pigmentation

In particular, the researchers found that two genes, PAX3 and PAX7, known to affect snout length and shape in laboratory mice, as well as skin pigmentation, were expressed at higher levels in chimpanzees than in humans. Humans with less than the normal amount of PAX3 have a condition called Waardenburg syndrome, which includes craniofacial, auditory and pigmentation defects. Genomewide association studies in humans have identified PAX3 as a region involved in normal facial variation.

In contrast, another gene known to be involved in determining the shape of the beaks of finches and the jaw of a fish called a cichlid was expressed at higher levels in humans than in chimpanzees. In mice, overexpression of this gene, BMP4, in cranial causes a marked change in face shape, including a rounding of the skull and eyes that are more near the front of the face.

"We are now following up on some of these more interesting species-biased enhancers to better understand how they impact morphological differences," said Wysocka. "It's becoming clear that these cellular pathways can be used in many ways to affect facial shape."


Explore further

About face: Long-ignored segments of DNA play role in early stages of face development

Journal information: Cell

Citation: Scientists home in on origin of human, chimpanzee facial differences (2015, September 10) retrieved 16 July 2019 from https://phys.org/news/2015-09-scientists-home-human-chimpanzee-facial.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
444 shares

Feedback to editors

User comments

JVK
Sep 10, 2015
See also: http://phys.org/n...ion.html

Re: "The key lies in how genes involved in facial development and human facial diversity are regulated—how much, when and where the genes are expressed— rather than dissimilarities among the genes themselves."

My comment: All serious scientists know that the key lies in the nutrient-dependent RNA-mediated pheromone-controlled vertebrate physiology of reproduction, which is clearly linked from biophysically constrained protein folding chemistry to chromosomal rearrangements and biodiversity.

See for example: Estrogen receptor α polymorphism in a species with alternative behavioral phenotypes http://www.pnas.o...abstract

Only biologically uninformed science idiots believe that vertebrates share DNA but not G protein-coupled receptor-mediated nutrient-dependent gene regulatory mechanisms, which are perturbed by viruses that are linked to all pathology.

Sep 10, 2015

by viruses that are linked to all pathology.


Still waiting for your peer reviewed evidence that "viruses that are linked to ALL pathology"

Sep 11, 2015
Gene regulation +network+ JVK, emphasis on network, not your simpleton's one-trick quack-quack.

See how this comprehensive, balanced and well-cited description of gene regulatory networks does not mention the words nutrient, pheromone or virus a single time:

https://en.wikipe..._network

James V Kohl, young earth creationist, posting the same 3 sentences every day on the same web site for the last 5 years. What a bore.

JVK
Sep 11, 2015
Still waiting for your peer reviewed evidence that "viruses that are linked to ALL pathology"


Viral and Cellular Genomes Activate Distinct DNA Damage Responses
http://dx.doi.org...5.07.058

Excerpt: "Central to life is the faithful replication, inheritance, and maintenance of genomic DNA. The MRE11/RAD50/NBS1 (MRN) complex and ATM play a critical role in this biological mandate (Ciccia and Elledge, 2010). Cellular double-strand breaks (DSBs) are sensed by MRN and trigger the assembly of DNA damage response (DDR) foci that amplify global ATM signaling to induce cell-cycle arrest and DNA repair (Polo and Jackson, 2011). DNA viruses are an ancient and persistent threat to both cellular genome integrity and viability."

...posting the same 3 sentences every day on the same web site for the last 5 years.


Biologically uninformed science idiots, incapable of understanding top-down causation and bottom-up pathology.

JVK
Sep 11, 2015
See how this comprehensive, balanced and well-cited description of gene regulatory networks does not mention the words nutrient, pheromone or virus a single time:


How can anyone be so ignorant as to not link metabolic networks to genetic networks, and link to Wikipedia?

See for comparison:
Exosomes and the RNA-mediated future of medicine
http://rna-mediat...edicine/


Sep 11, 2015
blah blah whine cry pseudoscience interpretations of real science blah blah Biologically uninformed science idiots, incapable of understanding BOHOO cry whine

so, you can't actually understand your failure here.... and you refuse to answer Anon here: http://phys.org/n...eal.html

what is next?
are you going to link some random study you don't understand again?
you do know, we will simply inquire to the author and then actual science from them, right?

why do you continue to promote yourself as some serious scientific researcher when it has been proven, despite your previous publications, that you are promoting creationist pseudoscience?

oh yeah, almost forgot
://rna-mediat./
PSEUDOSCIENCE CREATIONIST SITE
PHISHING SITE
reported

you can't have it both ways... you can't PROMOTE PSEUDOSCIENCE as actual science and consider yourself a scientist

EPIC FAIL

Sep 11, 2015

See for comparison:
Exosomes and the RNA-mediated future of medicine
....//rna-mediat...edicine/
about this site
if you can't link to a REPUTABLE PEER REVIEWED JOURNAL then you are NOT LINKING SCIENCE

this site is KNOWN for promoting creationist dogma and religious POV's... it is PSEUDOSCIENCE

when you MIX PSEUDOSCIENCE with actual science, it can NO LONGER be a science site, it is a PSEUDOSCIENCE site, because of the implications of your creationist pseudoscience

JVK
Sep 11, 2015
You ignore all links to articles from peer-reviewed journals unless they attest to the pseudoscientific nonsense of your religious belief in ridiculous neo-Darwinian theories.

See also:

Paternal Stress Exposure Alters Sperm MicroRNA Content and Reprograms Offspring HPA Stress Axis Regulation http://www.jneuro...abstract

The Placenta as a Mediator of Stress Effects on Neurodevelopmental Reprogramming
http://www.ncbi.n...26250599

Sep 11, 2015
ridiculous neo-Darwinian theories.

@JVK

You need to drop the "neo", You despise everything associated with Darwin and evolution.

Sep 11, 2015
Still waiting for your peer reviewed evidence that "viruses that are linked to ALL pathology"


Viral and Cellular Genomes Activate Distinct DNA Damage Responses
http://dx.doi.org...5.07.058

Still waiting.

JVK
Sep 11, 2015
Epigenetic regulation of Smad2 and Smad3 by profilin-2 promotes lung cancer growth and metastasis
http://www.nature...230.html

Excerpt: "...implicated in tumor development and progression. However, the molecular mechanism behind this alteration is poorly understood."

My comment: What do they claim is poorly understood about the biophysically constrained chemistry of altered RNA-mediated protein folding?

Why don't they simply admit that the molecular mechanisms are nutrient-dependent and virus perturbed?

See also: SMAD2, SMAD3 and SMAD4 mutations in colorectal cancer. http://www.ncbi.n...23139211

MicroRNA-627 Mediates the Epigenetic Mechanisms of Vitamin D to Suppress Proliferation of Human Colorectal Cancer Cells and Growth of Xenograft Tumors in Mice
http://www.ncbi.n...3722307/

JVK
Sep 11, 2015
You need to drop the "neo", You despise everything associated with Darwin and evolution.


You need to learn why Darwin placed "conditions of life" before natural selection and stressed the links between ecological variation and ecological adaptation before neo-Darwinists invented their ridiculous theories about how long it might take mutations to lead to the evolution of a new species.

See also: Periodic Scarred States in Open Quantum Dots as Evidence of Quantum Darwinism reported as http://phys.org/n...808.html

"The basis of almost any theoretical quantum-to-classical transition lies in the concept of decoherence. In the quantum world, many possible quantum states "collapse" into a single state due to interactions with the environment. To quantum Darwinists, decoherence is a selection process, and the final, stable state is called a "pointer state." Although pointer states are quantum states, they are "fit enough" to be transmitted..."

Sep 12, 2015
Darwin's five theories were:

"Evolution: species come and go through time, while they exist they change.
Common descent: organisms are descended from one, or several common ancestors and have diversified from this original stock
Species multiply: the diversification of life involves populations of one species diverging until they become two separate species; this has probably occurred billions of times on earth!
Gradualism: evolutionary change occurs through incremental small changes within populations; new species are not created suddenly.
Natural selection: evolutionary change occurs through variation between individuals; some variants give the individual an extra survival probability."
http://darwin200....ge_id=d3

@JVK

You've mocked all of this. Like I said, you need to drop the the "neo".


JVK
Sep 12, 2015
Biologically uninformed science idiots continue to ignore the basis for Darwin's theory. Neo-Darwinists put natural selection before ecological variation and nutrient-dependent conditions of life that enable the fixation of RNA-mediated amino acid substitutions like the one that differentiates us from gorillas, but not from chimpanzees.

http://rsif.royal...7?cpetoc
Excerpt: Biological organisms rely on their ability to sense and respond appropriately to their environment.

The experience-dependent de novo creation of olfactory receptor genes in primates is linked to differences in morphology and behavior via a single amino acid substitution.
"...the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla. ( p. 127)"
Dobzhansky (1973) http://www.jstor..../4444260

Sep 12, 2015
You ignore all links to articles from peer-reviewed journals
@jk
no, I don't… but just because you link a legit article doesn't mean it says what you THINK it says, either…

I do tend to attempt to contact authors to validate your "claims" and "interpretations"… but so far, few authors will allow me to post their replies because they don't believe in [paraphrased by me]
debating actual science with pseudoscience that is obviously so wrong that anyone with even a limited education in biology, like freshmen high-schoolers or basic EMT's, can spot it's blatant fallacies
now, even though I paraphrased that, SOME of it comes straight from multiple authors about your posts, jk!

I asked permission to re-post their replies, but was denied.
& because I respect hardworking scientists (real ones), I accepted their reasoning and acquiesced to their requests – but that doesn't mean I can't allude to their comments… because I don't name names.

2Bcont'd

Sep 12, 2015
@jk cont'd
...religious belief ...neo-Darwinian theories
we've already been through that argument. I don't have "neo-Darwinian" anything… not even socks, let alone religion (something that I despise and consider as a pandemic blight, btw)
See also:
I would rather you "see also" and "REPLY TO" this argument from ANON
Do you not know the difference between polypeptides and nucleic acids?
http://phys.org/n...eal.html

I (and everyone else) noticed you couldn't answer ANON… nor could you provide intelligent discourse… you attacked with redirection and red-herring, OBFUSCATION, techno-babble

WHY IS THAT?
the answer is simple: YOU DON'T KNOW!

PROVEN conclusions:
-you use your Dunning-Kruger to spout techno-babble to obfuscate issues
-you are mostly illiterate considering the lexicon of your field
-you are NOT educated in biology
-you are narcissistic and controlling
-you promote PSEUDOSCIENCE

JVK
Sep 12, 2015
I asked permission to re-post their replies, but was denied.


Only the biologically uninformed science idiot, Andrew Jones, has publicly criticized my model. When you add the fact that there is no other model, what you have is people unwilling to publicly comment for fear that their ignorance will be exposed -- as was Jones' ignorance.

Why are other biologically uninformed science idiots not challenging me in any forum by providing experimental evidence of what they think is biologically based cause and effect?

See: Genetics: Dawkins, redux http://dx.doi.org.../525184a
reported as: http://creationre...eviewer/

All that is required of theorists is to link the epigenetic landscape to the physical landscape of DNA via what is currently known about RNA-mediated metabolic networks and genetic networks. If they can't do that, what good are they?

JVK
Sep 12, 2015
Re:
anyone with even a limited education in biology, like freshmen high-schoolers or basic EMT's, can spot it's blatant fallacies


I reiterate: "All that is required of theorists is to link the epigenetic landscape to the physical landscape of DNA via what is currently known about RNA-mediated metabolic networks and genetic networks. If they can't do that, what good are they?"

See: https://www.googl...mediated

Why aren't theorists commenting at http://rna-mediated.com/ Excerpt: Here you will find information that links physics, chemistry, and molecular epigenetics via RNA-mediated events such as the de novo creation of olfactory receptor genes in order to encourage a public discussion of a paradigm shift.

It should be obvious by now that the content at RNA-mediated.com is receiving considerable attention by people who are biologically informed at the same time that science idiots, like you, are down-voting my comments here.

JVK
Sep 12, 2015
GnRH is the decapeptide that links cell type differentiation from yeasts to mammals via the RNA-mediated nutrient-dependent pheromone-controlled physiology of reproduction, which we placed into the context of molecular epigenetics in our 1996 Hormones and Behavior review.

From Fertilization to Adult Sexual Behavior http://www.hawaii...ion.html

See the section on molecular epigenetics.

See also: Feedback loops link odor and pheromone signaling with reproduction http://www.cell.c...l%3Dtrue

Sep 12, 2015
" On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. In the 1872 sixth edition "On" was omitted, so the full title is The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. This edition is usually known as The Origin of Species.[3] Darwin's book introduced the scientific theory that populations evolve over the course of generations through a process of natural selection. It presented a body of evidence that the diversity of life arose by common descent through a branching pattern of evolution."
https://en.wikipe..._Species

@JVK

Notice "natural selection" is in the title, refuting your claims about both Darwin and "neo" Darwinism. Everything you write is contrary to Darwin, Just admit you believe Darwin was wrong about everything, after all that's what creationists believe.

JVK
Sep 12, 2015
http://www.bartle...011.html

IV. Natural Selection; or the Survival of the Fittest

Summary of Chapter

Excerpt:
IF under changing conditions of life organic beings present individual differences in almost every part of their structure...


For example, when the conditions of life changed, the bacterial flagellum re-evolved over the weekend. http://www.the-sc...ewiring/

When the conditions of life did not change there was no evidence of "evolution." http://phys.org/n...ars.html

Notice "natural selection" is in the title, refuting your claims...


What kind of biologically uninformed science idiot claims that putting something into a title refutes my claims about the biophysically constrained nutrient-dependent RNA-mediated "conditions of life" linked to the physiology of reproduction in all living genera?

Sep 12, 2015
Only ...publicly criticized my model
that is because you don't need science to refute stupidity- even though JONES took the time to show how SCIENCE trumps pseudoscience!
there is no other model
you mean, except for the THEORY of EVOLUTION...
notice it is a THEORY!
you know what that means in science? i know you don't, and that you won't read the link, but here it is
A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation
https://en.wikipe...c_theory

your "model" isn't even hypothesis because it uses creationist dogma and refuses to accept known VALIDATED facts, like beneficial mutations

that is why you promote it as though, somehow, the creationist vote will at some time in the future will become valid science!
that aint how science works, bubba
that is how RELIGION works

JVK
Sep 12, 2015
Search Results for ""conditions of life""
http://www.bartle...ubmit=Go

See also: Nutrient-dependent/pheromone-controlled adaptive evolution: a model.
http://www.ncbi.n...24693353

Sep 12, 2015
Why are other biologically uninformed science idiots not challenging me in any forum
because you post PSEUDOSCIENCE
by providing experimental evidence
BUT... BUT... you IGNORE actual evidence, like Lenski, Extavour, et all... so... even when they DO argue, you are the religious zealot pushing a known creationist ideal that is unproven and NOT BASED IN SCIENCE
despite any of your past publications... UNTIL you can release your creationist dogma, you will continue to be shunned by actual scientists because you do NOT PUSH SCIENCE... this is obvious on your own personal (multiple) sites, from your perfume to OTHER sites which you continue to post PSEUDOSCIENCE and CREATIONIST dogma and conclude they hold the same weight as experimental evidence or science.

when people talk about religious fanaticism, trolling and PSEUDOSCIENCE... you are the poster child for it as THE example that defines it all

and that isn't trolling, that is PROVEN FACT

JVK
Sep 12, 2015
your "model" isn't even hypothesis because it uses creationist dogma and refuses to accept known VALIDATED facts, like beneficial mutations


Introduction: The epigenetic effects of nutrients on intracellular signaling and stochastic gene expression appear to enable adaptive evolution of tightly controlled organism-level thermoregulation in mammals. Nutrient-dependent single amino acid substitutions and de novo protein biosynthesis exemplify the involvement of the seemingly futile thermodynamic control of intracellular and intermolecular interactions in microbes that result in stochastic gene expression.

5.5 minute-long video representation http://youtu.be/DbH_Rj9U524


Sep 12, 2015
See also: Nutrient-dependent/pheromone-controlled adaptive evolution: a model

and i will say this again...
you are posting a MODEL... this isn't even hypothesis as it is not VALIDATED
that is just for starters

for more... it is also REFUTED by scientific evidence, starting here:
http://www.socioa...ew/24367

and ending with the evidence refuting you (and your model) here:
http://myxo.css.m...dex.html

continuing to ASSume that your "model" has the same authority or weight in science as the THEORY of evolution is like your continued insistence that you are a serious scientist as well as diagnostician with experience while not only being NOT licensed to practice, but also promoting creationist literature!

IOW- you directly refute yourself with your own words, mensa-bubba

JVK
Sep 12, 2015
Clinically Actionable Genotypes Among 10,000 Patients With Preemptive Pharmacogenomic Testing

2.5 minute-long video https://www.youtu...G_9EEeeA

See also:
http://rna-mediat...edicine/
http://rna-mediat...icine-2/
http://rna-mediat...icine-3/

Sep 12, 2015
2.5 minute-long video https://www.youtu...G_9EEeeA
youtube is not a peer reviewed journal anymore than watching Jerimiah Johnson is an accurate depiction of how to skin a griz
See also:
//rna-mediat...edicine/
/rna-mediat...icine-2/
//rna-mediat...icine-3/
PSEUDOSCIENCE PHISHING SITE
reported

this is NOT a peer reviewed reputable journal

IF you can't produce a study from a REPUTABLE PEER REVIEWED SCIENCE JOURNAL and you have to link to CREATIONIST SITES, then you are simply pushing PSEUDOSCIENCE

this is why you continue to FAIL in your argument: your links go to PSEUDOSCIENCE SITES
you have NO reputable information to share...

JVK
Sep 12, 2015
IF you can't produce a study from a REPUTABLE PEER REVIEWED SCIENCE JOURNAL ...


Clinically Actionable Genotypes Among 10,000 Patients With Preemptive Pharmacogenomic Testing http://www.medsca...24253661

Excerpt: "The frequency with which patients harboring actionable variants are exposed to the medications of interest, the degree to which providers make use of genotype-guided CDS, and the extent to which adverse therapeutic outcomes will be reduced remain to be determined."

The fact that the actionable variants are nutrient-dependent and RNA-mediated via fixation of amino acid substitutions in the context of the physiology of reproduction links nutritional epigenetics to pharmacogenomics.

See also: The Influence of Early Life Nutrition on Epigenetic Regulatory Mechanisms of the Immune System http://www.mdpi.c...4706/htm

JVK
Sep 12, 2015
See also: http://news360.co...0380784#

Excerpt:

Exosomes: The 'Missing Link' In How Plants and Animal Cells Communicate and Collaborate

This is the first study of its kind to look at the role of exosomes, small vesicles secreted by plant and animal cells that participate in intercellular communication, in interspecies (plant-animal) communication.

Sep 13, 2015
Good thing about those differences. Hate it if all of us looked like Donald Trump....with a rump to match.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more