What is the creature that is most distantly related to humans? This is a fascinating question that touches on multiple areas of biology. Before answering this question, we need to make it clear that the distance of kinship is not judged by us subjectively, but by the comprehensive comparison of genes, morphology, physiology and behavior of organisms.
First, let's clarify the concept of kinship. Kinship refers to the blood relationship between organisms, usually measured by genetic similarity. Therefore, the organisms that are most distantly related to humans should be which organisms are genetically different from humans the most.
In considering this, we also need to recognize the taxonomy of organisms. In taxonomy, kinship is determined by the taxonomic group in which the organism is located. According to the research of modern molecular biology, organisms are divided into multiple kingdoms, among which the animal kingdom is divided into multiple phyla, which are divided into multiple classes, which are divided into multiple orders, under which the order is divided into multiple families, under which the family is divided into multiple genera, and under which the genera is divided into multiple species. Therefore, we can infer the kinship of different organisms by comparing their positions in taxa.
According to the latest research, the creature most distantly related to humans may be sponges. Irish scientists published their findings in the journal Nature Communications, proving that sponges are distant relatives of humans, even farther than ctenophores.
Sponges are very primitive multicellular organisms that have a relatively simple structure and do not have complex structural features such as nervous system, muscles, and intestines. These complex structural features evolved after humans and sponges diverged.
The findings of this study imply that the structure of animal ancestors was simple, and that the evolution of complex structures such as muscles, nerves, and digestive systems all have a single origin.
It is important to note that although sponges are considered the farthest relatives of humans, this does not mean that they are the earliest or most primitive creatures on Earth. In fact, sponges, like some other single-celled organisms, evolved from a common ancestor, known as the luca (last common ancestor) of the Dynamic Incentive Program