In 2006, scientists found a fossil that seemed to have fish-like scales and four legs. It also had a bone structure in its neck
that suggested it could move its head. This fossil was given the name Tiktaalik and its discovery turned the scientific world upside down. What evidence does the discovery of Tiktaalik give to support the theory of evolution?
A. Tiktaalik shows that land animals and fish are not as closely related as once thought.
B. Tiktaalik shows that land animals and fish developed from completely different ancestors.
C. Tiktaalik shows that fish decided to grow legs at some point, which allowed them to walk on land.
D. Tiktaalik shows that extinct species are related to modern species, which supports the idea of common ancestry.
Scientists found a fossil of a fish with four limbs or legs. The fossil was estimated to be around 375 million years old.
The fossil showed the fins and scales of a fish but they also possess the bones of proto-wrist, shoulders and the elbow.
The presence of these bones can be a clue that the fish evolved the limbs to walk on the land and will later evolve into animals belonging to amphibians, reptiles and mammals. Therefore, the Tiktaalik is considered the missing link of how life evolved from water to land.
The genome of an organism is inscribed in DNA, or in some viruses RNA. The portion of the genome that codes for a protein or an RNA is referred to as a gene. Those genes that code for proteins are composed of tri-nucleotide units called codons, each coding for a single amino acid.
