"Because tooth enamel incorporates elemental isotopes and minerals from your diet as well as scratches and residue from hard foods you grind with your teeth, it may reveal where you’ve lived and what you’ve eaten over time. Permanent teeth, designed to last a lifetime, contain below their surface a microscopic record of
their growth, analogous to tree rings. “Teeth also preserve their growth bands,” explains Duke evolutionary anthropologist Christine Wall. “So in terms of understanding fossils, teeth can tell you how old a juvenile was when it died, or how long it takes for teeth to develop—so you can compare between living and extinct species.” But can teeth tell more?
Enamel thickness, though determined long before birth when enamel-producing cells build a precisely oriented protein framework for its mineral structure, does vary with a species’ typical diet. Human tooth enamel is, generally speaking, thicker than apes’. Many evolutionary paleontologists believe dietary changes contributed to the evolution of bigger brains and thus to human evolution.
The authors of the recent study think that the genetic distinctives that help make human tooth enamel thick are the footprints of selective changes that led to the evolution of modern humans.
Enamel is the hardest, most mineral-rich substance in the human body. Covering a tooth’s crown long before it erupts from the gum, human enamel is usually thickest on the top.
“We decided to look just at genes that have a known role in tooth development,” explains Duke University biology professor Greg Wray. Four proteins involved in tooth formation are enamelysin, amelogenin, ameloblastin, and enamelin. Mutations in the genes controlling production of these proteins are associated with abnormal enamel formation. The team compared genes in humans and five primate animals that they believe all share a common ape-like ancestor. They believe differences between them trace the evolution of each species, and they also believe that the greatest differences indicate the genes most favored by natural selection in the course of evolution over millions of years. “That's when we know a gene is under positive selection,” says lead author Julie Horvath.
MMP20 and ENAM, the genes for two of the proteins, enamelysin and enameliin, respectively, had significant interspecies differences in the regulatory regions that control their transcription. The protein-coding parts of the genes did not differ significantly between species, and the genes for the other two proteins did not differ. Therefore the team concludes that in the course of human evolution changes in the regulation of transcription of these two genes contributed to us becoming what we are, selectively favoring us to eat the kinds of foods we do and ultimately to evolve our bigger brains. They write, “We expect mutations affecting gene expression to comprise an important part of the genetic basis for dietary adaptations during human evolution.”
What the researchers in this study observed are the two areas of the enamel-producing blueprint that differ between humans and primate animals. Since enamel tops teeth of both, it is no surprise that these human differences occur in the regulatory parts of these genes, the parts that control transcription, rather than the genes that code for the enamel-building proteins themselves.
God our Common Designer used many common designs and variations as He created humans and animals,.....This study has taught us more about God’s design for teeth, not about the ascent of and divergence of teeth up the evolutionary tree of life." AIG
I will give thanks to you, For I am fearfully and wonderfully made.
Your works are wonderful.
Psalm 139:14 HNV
Enamel thickness, though determined long before birth when enamel-producing cells build a precisely oriented protein framework for its mineral structure, does vary with a species’ typical diet. Human tooth enamel is, generally speaking, thicker than apes’. Many evolutionary paleontologists believe dietary changes contributed to the evolution of bigger brains and thus to human evolution.
The authors of the recent study think that the genetic distinctives that help make human tooth enamel thick are the footprints of selective changes that led to the evolution of modern humans.
Enamel is the hardest, most mineral-rich substance in the human body. Covering a tooth’s crown long before it erupts from the gum, human enamel is usually thickest on the top.
“We decided to look just at genes that have a known role in tooth development,” explains Duke University biology professor Greg Wray. Four proteins involved in tooth formation are enamelysin, amelogenin, ameloblastin, and enamelin. Mutations in the genes controlling production of these proteins are associated with abnormal enamel formation. The team compared genes in humans and five primate animals that they believe all share a common ape-like ancestor. They believe differences between them trace the evolution of each species, and they also believe that the greatest differences indicate the genes most favored by natural selection in the course of evolution over millions of years. “That's when we know a gene is under positive selection,” says lead author Julie Horvath.
MMP20 and ENAM, the genes for two of the proteins, enamelysin and enameliin, respectively, had significant interspecies differences in the regulatory regions that control their transcription. The protein-coding parts of the genes did not differ significantly between species, and the genes for the other two proteins did not differ. Therefore the team concludes that in the course of human evolution changes in the regulation of transcription of these two genes contributed to us becoming what we are, selectively favoring us to eat the kinds of foods we do and ultimately to evolve our bigger brains. They write, “We expect mutations affecting gene expression to comprise an important part of the genetic basis for dietary adaptations during human evolution.”
What the researchers in this study observed are the two areas of the enamel-producing blueprint that differ between humans and primate animals. Since enamel tops teeth of both, it is no surprise that these human differences occur in the regulatory parts of these genes, the parts that control transcription, rather than the genes that code for the enamel-building proteins themselves.
God our Common Designer used many common designs and variations as He created humans and animals,.....This study has taught us more about God’s design for teeth, not about the ascent of and divergence of teeth up the evolutionary tree of life." AIG
I will give thanks to you, For I am fearfully and wonderfully made.
Your works are wonderful.
Psalm 139:14 HNV
