Final answer:
The host necessary for body lice is humans, who started wearing clothes made from animal hides as they migrated into colder climates. This led to the adaptation of body lice to live on clothing rather than on body hair. The coevolution of humans and lice provides insights into the timelines for human development and migration.
Step-by-step explanation:
The necessary host for clothing or body lice is humans. These parasites have coevolved with humans and have a unique adaptation to live and lay their eggs on clothing fibers. The development of hominin bipedalism and subsequent loss of body hair in hominids made the creation of clothing a necessity when humans moved into colder climates. This can be traced back to the Paleolithic era when individuals started making simple clothing from animal hides using tools such as bone sewing needles. These changes were crucial for survival, providing warmth and facilitating the spread into various environments with more extreme temperatures.
Research by Dr. David Reed and others suggests that while humans may have lost most of their body hair around a million years ago, the wearing of clothes did not begin until approximately 170,000 to 190,000 years ago. The coevolution with lice provides significant insights into this historical transformation and is an indicator of early clothing use. By examining the genetic diversity of lice, especially in Africa, researchers support the Out of Africa model of human migration and provide further understanding of the human-lice coevolutionary relationship.