Human beings and a vast array of vertebrates could well have descended from a common ancestor with a well-developed sixth sensory system, a new study suggests.
The common ancestor is believed to be an aquatic vertebrate, probably a predatory marine fish that could detect electric fields produced from its prey in the water, the study published Tuesday in Nature Communications reports. In today's oceans, sharks, paddlefishes and several other aquatic vertebrates have similar sensory systems, dubbed as the “sixth sense,” to help detect movement underwater.
According to researchers, some 65,000 species of aquatic and terrestrial vertebrates, including Homo sapiens, could have descended from a species of marine fish that is believed to have existed about 500 million years ago.
The researchers found that electrosensory organs, in a vast majority of vertebrates, develop in a similar pattern, raising the question of its common evolutionary heritage.
The study, led by British researchers, is expected to throw light on inquiries into the evolutionary lineage of the original vertebrates that later formed aquatic and land vertebrates we know today.
Hundreds of millions of years ago, there was a major split in the evolutionary tree of vertebrates. One lineage led to the ray-finned fishes, or actinopterygians, and the other to lobe-finned fishes, or sarcopterygians; the latter gave rise to land vertebrates, said Willy Bemis, a senior author of the research paper, in a report by Science Daily.