Lab of Biological Anthropology

We all live one life, and each of us has a story to tell. If you had been born as the child of your next-door neighbor, as a hunter-gatherer in the past, or as a chimpanzee in the African rainforest, how would you have grown up, had or not had children, and died? The Laboratory of Biological Anthropology reconstructs and describes these different "we" (Homo sapiens and other evolutionarily related species), and examines the impact of differences in culture and natural environment on "our" lived experience, and how these differences affect evolutionary and adaptative consequences and social conditions over a long period of time. We also investigate the impact of differences in culture and natural environment on our lived experiences and clarify how these differences in our individual ways of life affect evolutionary and social consequences over a long period of time.

If you interview people living in the same modern era, they will tell you about their individual lived experiences. But what if you are talking to a monkey who doesn't speak human's language or someone from the past who is already dead? This is where analyses of biomolecules come in handy. Feces, hair, bones, teeth, and other body tissues record an individual's way of life and, when properly analyzed, can provide information about certain aspects of their lived experiences. Although such information is often limited, it is still very useful.

We mainly investigate lived experiences of past humans and extant primate species. We apply stable isotope analysis to biological samples to reconstruct their diet, breastfeeding/weaning patterns, and living environment. We apply proteomic analysis to estimate physiological conditions, species, and body tissues of the target samples. We also develop analytical methods that can reconstruct different aspects of life. However, we are not bound by any subject or approach. We also investigate the lives of non-human vertebrates and conduct sociological interviews with modern humans.  Our scientific approaches range from the field to the lab. For example, we are participating in excavations and wildlife studies to collect samples and data, pre-processing and analyzing the samples in the laboratory, and using computers to analyze data and develop programs to build mathematical models.

We has conducted the following research, among other themes.

Bioarchaeology

We have been analyzing ancient human and animal bones excavated from archaeological sites to investigate their lived experiences in the past. Particular attention has been paid to childbearing, child-rearing, diet, and death. These are important determinants of the demographic and health status of biological populations. We hope to clarify how cultures and natural environments affect lived experiences of humans and animals, and how they influence evolution and social situations.

Using stable isotope, palaeoproteomic, and ancient DNA (palaeogenomic) analyses to examine trace amounts of biomolecules left in archaeological remains, we reveal life phenomena in the past that we can no longer observe. We are collaborating with archaeologists and physical anthropologists and participating in excavations and the process of bone specimens.

For example, the following studies have been conducted so far: 

• Investigating differences between descriptions about child-rearing in premodern books and actual child-rearing practices

• Reconstructing the way of death of a dog neonate that died approximately 1,000 years ago

• Reconstructing the life of a premodern female

• Reconstructing how long children were breastfed in the Jomon hunter-gatherers

• Developing mathematical models for interpreting bioarchaeological data (See: Post-weaning Diet In Archaeological Human Populations)

• Reconstruction of changes in the marine environment and human fishing activities based on the analysis of fish bone stable isotopes

Primate ecology

We study chimpanzees, orangutans, and other primates, which are evolutionary related to humans, to investigate biological phenomena that are difficult to study from behavioral observations. By identifying individual primates and observing their behavior, we can investigate a lot about them. However, some behaviors are difficult to study from observation or require too much time and effort to investigate from observation. We hope to solve these problems by applying stable isotope and proteomic analyses.

We are investigating the development, feeding habits, and health status, using stable isotope and proteomic analyses of biological samples that can be collected non-invasively, such as feces, hair, and food samples. We conduct basic studies on captive individuals in zoos and apply them to wild individuals. We collaborate with primatologists and ecologists and participate in field research.

For example, we have conducted the following research so far:

• Studying the diet and breastfeeding/weaning patterns of wild orangutans in Malaysian Borneo

• Studying the differences in diet and habitat between wild chimpanzees and guenons living in the same forest of Uganda

• Developing a new method (ecoproteomics) for estimating diet and physiological conditions in captive Japanese macaques

Palaeome

Palaeoome (palaeo + ome) studies are conducted to directly reveal the evolutionary process of animals by applying omics technology to ancient remains. We are analyzing ancient proteomes and ancient genomes, focusing mainly on animal fossils from the Pleistocene. By combining molecular evidence with the knowledge accumulated in paleontology, we aim to better understand the evolutionary history of several taxa that experienced extinctions in the past.

For example, the following studies are underway:

• Phylogenetic estimation and sex determination of Proboscidea (elephants) that once inhabited the Japanese archipelago and became extinct

• Resolving phylogenetic relationships among several taxa in Cevid (deer) in the Japanese archipelago, including extinct ones

• International collaborative research mainly in East Asia

Mismatch between culture and biology

We investigate and discuss the mismatch between the biological characteristics of humans, that have acquired through evolution, and the current socio-cultural state of modern human society. We also collaborate with sociologists on research on the diversity of child-rearing practices in modern Japan, such as those practices in a shared house.

The PI's question "Why is it so difficult to raise a child in Japan today?" led this research topic, and therefore particular attention is paid to pregnancy, childbirth, and parenting. The common sense and social norms that bind us to modern child-rearing have rapidly changed over the years to decades. By providing knowledge of human evolution that takes into account millions of years of time frames, we hope to bring in a slightly different perspective and contribute to the healthier child-rearing practices.

For example, we have conducted the following research so far:

• Discussions on the mismatch between biological characteristics and contemporary socio-cultural environment in modern human breastfeeding and weaning practices

• A sociological investigation of cooperative child care which involves diverse adults other than parents and relatives