The limbs had evolved from fins; during the transition, our back-boned ancestors lost rows of rigid fibers, called actinotrichia, that provide structural support and guide fin development. The number of digits was also later winnowed to a maximum of five on each limb.Jun 23, 2010
Did hands evolve from fins?
This tetrapod-like fish lived more than 380 million years ago, and belonged to a group called elpistostegalians. Our research based on this specimen, published today in Nature, suggests human hands likely evolved from the fins of this fish, which we'll refer to by its genus name, Elpistostege.
What type of fins did tetrapod limbs evolve from?
The forelimbs of tetrapod evolved from the pectoral fins of the ancestral fish. These fins contain three or more basal bones connected to the pectoral (shoulder) girdle.
Why did fish evolve limbs?
From these finds, it now appears that the four legs common to land animals today really evolved for another purpose: navigating swampy wetlands, not as a means of moving to land. But once on land, the animals found their limbs a survival advantage there, too.
Can a fin become a limb?
Unlike limbs, which have complicated bone structures and numerous joints, zebrafish fins are fairly simple. The team discovered that a small genetic mutation caused the pectoral fins to develop a more limb-like pattern, with additional bones, along with muscles and joints.
Did humans evolve from monkeys or from fish?
Like modern-day apes and monkeys, we evolved from ancient monkeys. And like all vertebrates with four-limbs, known as tetrapods, we evolved from the same ancient fishes. The more living relatives we include in a family, the farther back we must go to find that family's common fossil ancestors.
Did human beings evolve from fish?
The Human Edge: Finding Our Inner Fish : NPR. The Human Edge: Finding Our Inner Fish One very important human ancestor was an ancient fish. Though it lived 375 million years ago, this fish called Tiktaalik had shoulders, elbows, legs, wrists, a neck and many other basic parts that eventually became part of us.
How did tetrapod limbs evolve?
All tetrapods descended from a common ancestor that just happened to have limbs with five digits. And over the eons of evolution following that, natural selection worked with variations on pentadactyly rather than starting over again to produce tetrapods with another number of digits, be it two, seven, or 17.