In 1848 George Romanes was born in Kingston, Ontario, but when he was a child his parents moved to Britain. This was probably one of the best things that could have happened to young Romanes, for he eventually got to meet Charles Darwin, and he became one of his close friends. They became so close that Darwin gave him full access to his notes on animal behavior, which Darwin had worked on for years.
The last twenty years of Romanes life was devoted to the study of invertebrate physiology. He was constantly trying to show the development of "intelligent" behavior of a particular species was related to their placement on the evolutionary scale. In fact, he was able to find that the nervous system of the jellyfish acted as if it were a network of connected units. If the jellyfish was to be poked in an area, the organism would contract around that point. From this discovery, the synapse was later revealed.
Romanes's Animal Intelligence (1882) was the first attempt to describe the behaviors of animals in the context of evolution. While writing this book, he often had to rely on stories of events from respectable figures, (pet owners, naturalist, travelers) which would lead to some questioning. Although he was forced to use these sources, Romanes still tried to be as careful as possible in selecting his material for reliable witnesses. He went to great pains to avoid hearsay, and was prone to describe revenge or altruism as human motives. Insects receive the most coverage from Romanes in this book, there are almost two hundred pages on insects.
Romanes's final book, Mental Evolution in Animals (1893), attempted to related animal instinct and animal intelligence to evolution. One question Romanes discussed was wether or not a learned skill can be inherited. His theory was that if an animal did an intelligent act, then the desire to repeat this skill could be passed on.
Romanes attempted to relate psychological development and evolutionary advancement. First, he demonstrated that animals could show intelligence in Animal Intelligence. Then he tried to show that the animals that act more advanced and humanlike were higher on an evolutionary scale. Finally, he argued that language could have appeared naturally, by natural selection.
Romanes began to do studies on the basis of hybrid sterility. He published Physiological Selection: An Additional Suggestion on the Origin of Species, in 1886. This article added to the thoughts of origin of species. It was often times ignored and even criticized until recent years when information suggested that Romanes had solved many of the problems with Darwin's theory. He explained that it was obvious that reproductive isolation was more likely to depend on differences in the chromosomal information than in the genetic information. This theory was also investigated by Bateson & Saunders (1902), they were also criticized. They were all criticized because the genetic viewpoint was simple and easy for people to believe. Many felt that genetics explained everything. Romanes and Bateson did not have as much faith in this viewpoint as others did and only now are we able to realize the points they were trying to make.
Romanes believed that there were barriers between species which protected them from infectious diseases. There are two types of barriers, external and internal. The external barriers are hygienic measures and the internal barriers are each organisms immune response. It was also found that we can detect a mate that will produce healthy children rather than choosing an incestuous relationship which would result in less healthy children or even more extreme the relationship with another species. The relationship with another species is prohibited by species barriers. Even if the barriers did not exist, a cell may be unable to grow into an adult organism even if the female ovum was fused with the male sperm.
There was some problems with Darwin's theories that needed to be made clear. For example, hybrid sterility had not been explained well. The cross of a horse with and ass is usually fertile, but the hybrid progeny, a mule is sterile. Romanes was able to clear thing up with his ideas on physiological selection. One of the most apparent barriers between closely related species would be the sterility barrier. He used the example of height and eye color and how no one knew what caused variations. Romanes explained that a variation could form and would make some organisms more sterile with other members of the species, but may not affect the somatic characters. This could be very devastating to a species, however, he explained that if both organisms had the same changes, then they would still be fertile with each other. This showed that from generation to generation, the cross of generations would result in a less fertile relationship. Of course, in a small population it would be very unlikely that a male and female whose gonads had undergone the same variation would appear at the same time. Although in a large population two individuals with the same rare gonadal variation might appear, there would be a small chance of them actually meeting. In small or in large populations there would not be much chance of the variation being present in large numbers. Romanes pointed out that successful variation seemed rare but possible. This type of evolution was called polytypic.
Although some of Romanes work was criticized, he would not have come up with his theories if he had not been criticized. He believed that evolution had gone through many stages, and he could demonstrate this through many species (Romanes, 1897). He used his work on jellyfish to show that the nervous system had evolved from the purpose of sending a message from one part to another. He could not show how it evolved, but he could show it on small organisms through a taxis.