October 11, 2019
The human body is the result of millions of years of evolution. During development the human embryo and fetus give us a glimpse into our deep ancestral past. For example, human embryos go through a stage of development where they have slits and arches on their neck like the gill slits and gill arches of fish. This similarity in development shows us that humans and fish had a common ancestor.
Researchers from Howard University and the Sorbonne University have discovered a new ancestral feature during human development. Using a special staining technique called immunostaining they have observed a group of limb muscles that were thought to been abandoned by our mammalian ancestors 250 million years ago. These so called ‘reptilian’ limb muscles are present in the hands and feet of seven-week-old embryo but have disappeared by the time the fetus is 13 weeks old.
Previous studies into the development of human limbs had been conducted during earlier stages before these muscles were present. Discovery of these ancient muscles sheds new light on our evolutionary history, and will hopefully encourage further investigation into other developmental changes.
Source: Science Alert
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