Analogy & Homology

The butterfly and the moth

A. A butterfly is an insect that tends to fly during the day from the order Lepidoptera, the butterflies and moths. The butterfly's life cycle consists of four parts, egg, larva, pupa and adult. Butterflies have large, often brightly colored wings with fluttering flight.

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Most moths are nocturnal with 150,000 to 250,000 different types of species, thousands still not found yet.

B. The homologous trait is the antenna that both butterflies and moths possess. With butterflies the antenna are clubbed while in moths they are tapered. In some species of moths the antenna are enlarged into feathered organs. There are differences between this homologous trait because moths are night insects which makes it harder to seek a mate, They are not able to see well so instead males have antenna that make them more capable to seek by smell, picking up pheromones produced by females.

C. The common ancestor of these two species has not yet been determined. It has been studied that by 40 million years ago, butterfly and moth families were already in existence. However, there is a theory that butterflies and moths originated within a crustacean group that includes water fleas and fairy shrimp around 400 million years ago. Even though it is not easy to determine the common ancestor of butterflies and moths, it is easy to assume that the common ancestor possessed this trait because without it they would not be able to sense in order to survive and evolve whether it is to find a mate in order to reproduce or determine where their food is.

The tortoise and the hedgehog

A. The tortoise comes from the family of reptiles. They use their shells to shield themselves from predators, containing an endoskeleton and an exoskeleton. They tend to be reclusive even though they are not nocturnal.

The hedgehog comes from the subfamily Erinaceinae. They are nocturnal animals, known to have been recognized by their spines which are actually hollowed hairs made to be stiff with keratin. Their “spikes” are not poisonous, but cannot be easily removed.

B. Both tortoises and hedgehogs share the analogous trait to draw into themselves when they feel threatened. The hedgehog curls into a ball protecting its vulnerable parts with its outer spines, and the tortoise retracts its vulnerables such as its head, tail and feet into its protective shell made of bone. The hedgehog uses its spines to protect the most precious parts of its body while the tortoise uses its shell. Both species have developed protective features on their bodies in order to keep predators away and protect themselves from danger.

C. Hedgehogs are mammals and tortoises are reptiles. They are very distantly related so it is likely that these two species would not have inherited their behavior of withdrawing themselves from danger from a shared ancestor.

Protein Synthesis

I hope I did this right!

UCCGTACCAAGGGAACGCAAGCCCCAGTCTGTTAATCACCA

Historical Influences on Darwin

There are many people who influenced Charles Darwin’s hypothesis, but I believe that one scientist in particular contributed the most to Darwin’s work. Charles Lyell was a geologist and was known to be “obsessed with the implications of the evolutionary theory. Not only was Charles Lyell “one of the first prominent scientists to support The Origin of Species,” but he was also a close friend of Darwin’s. Just by being friends with him, I feel that Lyell had such a great influence on Charles Darwin because they worked together frequently. They enjoyed each other’s company and debates about the theory of evolution. Charles Lyell lent a book that he wrote to Darwin called Principles of Geology while on the HMS Beagle in order to give him an idea of his own theory on the process of evolution. This trip is now famous because it is known that Darwin created his theory of natural selection while on this trip. Lyell’s theory in his book explains how new species would appear as older ones became extinct, one species could not evolve into another over time. Although this is quite the opposite of what Darwin proposed later on, I believe that Lyell’s opinion had a huge effect on Darwin’s thoughts because after reading this book, Darwin came up with his own theory of natural selection. This is the point of Darwin’s work that was greatly affected by Charles Lyell. Darwin was able to realize the flaws in Charles Lyell’s hypothesis and create his own as well as convince Lyell that his idea was much more practical and even managed to change Lyell’s beliefs completely. I do not think that Darwin would have been able to develop his theories of natural selection without the help of Charles Lyell. I feel that his theory of natural selection was able to be fathomed because he read Lyell’s book and without it, would not have had the idea of natural selection in his mind. The attitude of the church, which was an obvious amount of anger and disapproval, seemed to have a positive effect on the eventual publication of Charles Darwin’s book The Origin of Species. There were protests and negative public statements, but the book was repeatedly sold out. It seems to me that all of the unintended publicity that the church was giving to Darwin helped him raise awareness about his book and hypothesis.

Sources:

http://www.victorianweb.org/science/lyell.html

http://www.lycos.com/info/charles-lyell--charles-darwin.html