According to Charles Darwin evolution is the theory that Earth’s many species are descendants of ancestral species that were different from those living today. Darwin introduced to us one of the most cited reasons for evolution, known as natural selection. Natural selection is the process in which individuals with certain inherited traits are more likely to survive and reproduce than those individuals that do not have those traits. The squid, an advanced member of the class cephalopods, is an eminent example of evolution by natural selection. The squid has evolved several adaptations due to selective forces and predation pressure.
Squids have already been adapted with pre-existing variations for various different reasons. Squids do not have an outer shell like other members of the mollusc family. The shell has been reduced and internalized to help offer support to the mantle. This internal shell also attaches to the squids muscles to allow freedom and control of movement. The fusion of the squid’s head and foot has helped the squid develop a more efficient swimming method, now known for their fast swimming abilities. Unlike some other members of the mollusc family a squid doesn’t have a radula. They have evolved tentacles over time, which help them catch prey and aid them in eating their prey. In the squid the siphon is a modification of the foot. The siphon is used for locomotion in which muscular contractions force water through the siphon and help the squid propel through the water. There have been two big changes in squid that has helped them fight off predators, the ability to release ink and the ability to become translucent or camouflaged.
Even though a squid has already went through many adaptations they will continue to change as time goes on. One cause for this change is when selective forces occur, which is currently effecting a squid population near the coast of Wilmington, NC. A selective force is a change in a population that puts stress on an organism to survive and have surviving organisms. In Wilmington a new preda...
