Adoption is understood as a process by which a person assumes the upbringing of another person, usually a child. It is not ruled out that the adoption may be of an adult. However, the concept of “adoption” has changed throughout History. The modern form of adoption arose in the United States in the mid-19th century, when the American Civil War resulted in unprecedented overcrowding in orphanages and founding homes (Gomes et al. 2021
). Consequently, the Orphan Train movement of 1859 arose, which eventually sent some 2,000,000 children from urban centers to rural eastern regions; however, the children were generally hired rather than adopted (O’Connor 2004
Another concept that has changed in different times and societies is the family or family nucleus. Currently, it is understood in Western societies as a set of individuals who are genetically related, such as parents, children, grandparents, or uncles. Generally, we refer to a direct and generationally close family, but there are exceptions with family members further away from the family tree, such as a third cousin, for example. In a restricted sense, the “nuclear family” can be considered a group or a threesome comprising a father, a mother, and one or more children. There are cases of individuals who are not genetically related representing a role in the family of the adoptive child (Sumaza and Rodríguez 2003
). In this review, we will refer to these concepts of family or nuclear family and we will use it under this definition.
Throughout History, different forms of the adoption practice have appeared. The oldest well-documented adoption practices date to ancient Mesopotamia and Rome (Lindsay 2009
). Although there is no record of adoption in most ancient chronological periods, it is very important to note that this does not mean that the phenomenon of adoption did not exist, and this will have consequences for approaching an archaeological find.
Adoptions have been detected in many cultures throughout History but for different purposes. While the European Western idea of adoption focuses on extending family lines, the evidence suggests that the objective of this practice in Asiatic cultures was to ensure the continuity of cultural and religious practices (Baelo Álvarez 2013
From the moment of adoption, this individual is part of the new family and, therefore, will learn and carry out the traditions of the new family nucleus. Among these traditions, there are funeral or burial acts and practices after the death of an individual. These acts have been widely studied since the first populations of which we are aware. Thus, after the death of an individual from the group, as a religious–cultural practice, the body was buried or taken to a sacred or special place (Baelo Álvarez 2013
). These data will be very useful for our bibliographic review, which will consist of finding possible facts of adoption in archaeological sites. This is so because we will have a lot of information about different types of ceremonies and burial rituals and how they focused or did not focus on the family nucleus, in such a way that we can discriminate family groups between different burials.
Given the widespread cult of death in almost all cultures, human remains of ancient populations have been found that, through genetic studies, have shown that not all individuals are related. One possible interpretation is to think that it could have been an act of adoption. For example, there are cases of collective (simultaneous) burials, supposedly of a family, whose individuals were not related, where the family hypothesis was ruled out with molecular analysis (Palomo-Díez et al. 2018
). Adoption cannot be talked about in all cases in which we find unrelated individuals; it will be the researcher’s task to collect as much information as possible to be able to discriminate whether or not there is an adoption case.
Depending on space and time, adoption has undergone significant changes and modifications, following the characteristic cultural norms and values of each of the societies in which it has manifested itself as a legal–social act. From the nineteenth century (XIX century), adoptive parenthood acquired enormous relevance, interest, and social visibility. All this is a consequence of the decrease in fertility rates, the incorporation of women into the labor market (the average age at which they decide to have children was postponed), the separation of marriage from reproduction, social changes in maternity (abortion and contraception), and the increase in marital infertility rates, but adoption was already carried out in ancient societies as previously mentioned (Hernández et al. 2003
The analysis of genetics has had a great impact on society in the field of adoption. As a result, adopted people can know who their biological parents are. The right to identity implicates a wide range of ideas, among which is the right to know one’s biological origins. In terms of adoption, in Spain, for example, this issue was overcome with the entry of Law 54/2007 of December 28 on international adoption, which led to the recognition of this right for adopted children (Echegaray 2020
At the moment, genetic studies of parents concerned about their genetic descendants’ health are increasing. Diseases that may be in the parents as carriers who do not suffer from them and a high probability of passing on mutations that may lead their children to have a disease or malformation affect the parents’ decision to adopt (Joseph 2021
A typical situation could be families formed by a couple with descendants of previous marriages and/or relations. However, this case could be assumed as a special type of adoption, where one or both members of the couple “adopt” the offspring of the couple. In these cases, the cultural concept of family is not consistent with the biological concept of kinship. As for marriage between people of the same sex, in the same way as divorce, the simple relationship of a couple does not make sense analyzed from a genetic point of view unless the offspring of the couple is studied. In this case, we can find cases where only one of the members of the couple has a biological relationship with the descendants of the family nucleus, or, in the case of marriage between persons of the same sex with adopted descendants, where there is no biological link with the descendants (Gomes et al. 2021
). From a forensic point of view, many difficulties can be imagined when it comes to identifying a person whose parents or biological descendants are unknown. To solve this, many databases have been created that are used as tools to register personal DNA profiles, which will make statistical analyses between profiles of relatives and individuals to find matches (Carracedo et al. 2010
These same situations could have occurred in ancient societies along with facts such as not defining the family nucleus as we currently do and, for example, the fact that the family nucleus refers to a small region in which the family members live together. To this, we add the previously mentioned cases of finding family sites where the individuals are not genetically related or individuals in different sites that are genetically related. Due to all this, the question arises as to how we know whether we have an adoption case at a site. Our objective is to collect all the information possible to be able to determine if it is an adoption case or not.
2. Adoption: The Evolution of the Concept
Adoption has been practiced throughout Human History with its legal, social, and ethical implications (Paulissian 1999
). Legally considered as taking an individual born to others as one’s descendent, adoption dates to ancient times, although the procedure has considerably changed over time and is not common to all cultures (Eugena 2015
). The process is usually legal, but in some cultures adoption happens by social ritual. As part of the process of adoption, the adoptee’s legal relationship with the biological parents may be terminated (David 2003
There are plenty of motives for a family to adopt an individual, child, or adult. The death of parents from disease, famine, or war can contribute to the possibility that an individual, mainly a child, be adopted. However, the motives to adopt have been changing accompanying the ethical, social, and legal changes in each society. Some cases of adoption in ancient societies are briefly described below, as well as the main reasons for this practice (Baelo Álvarez 2013
2.1. Ancient Mesopotamian Society (Approximately 3250 b.C.–539 b.C.)
According to Eugena 2015, there were a significant number of orphans or abandoned children in ancient Mesopotamia. The ancient Mesopotamians had laws, social customs, and traditions that tried to protect the rights and interests of both the adopters and adoptees and the adoption contract was documented and corroborated by witnesses and sealed on tablets (Paulissian 1999
The most famous law code is the Codex Hammurabi where, regarding adoption, it could be read, for example: “If a man adopts a child and to his name as son, and rear him, this grown son cannot be demanded back again. If a man adopts a son, and if after he has taken him, he injures his foster father and mother, then this adopted son shall return to his father’s house. If an artisan has undertaken to rear a child and teaches him his craft, he cannot be demanded back” (excerpt from the Codex Hammurabi, lines 185–188).
The most common form was adopting a newborn baby. Concerning adults, they could become part of another family by their own will, called “arrogation” (Nemet-Nejat 1998
; Eugena 2015
The reasons ancient Mesopotamians adopted children were analogous to modern ones. Childless couples adopted orphaned or abandoned children to give them protection and family. It was also common for couples with their sons and daughters to adopt a son or a daughter, who would have the same civil rights as biological children, including inheritance rights. According to Eugena
), slaves could be adopted too.
Several adoption documents were found in different Near Eastern cities. One main difference from the law codes is that this information does not only act upon parent–child adoption but also sibling adoption, as well as the fact that women could also adopt (Vromans 2017
2.1.1. Adoption in Mesopotamia
One of the characteristic features of the ancient Mesopotamian civilizations that emerged from the lower channels of the Tigris and Euphrates rivers was the enormous influence that these civilizations exerted on the spiritual and material development of humanity.
Thanks to compiling work, all the traditions and social customs of the time were established in writing, to regulate and standardize private behavior in an agricultural livestock society, in which labor and commerce were the mainstays of its economy and the basis of social and religious life (Baelo Álvarez 2013
Among them, we highlight adoptive paternity and surrogate motherhood, contractual figures, with the purpose and social utility of perpetuating the family (religious) domestic cult and transmitting post mortem the heritage of the father of the family (indivisible and inalienable collective assets) in the absence of descendants, successors, or heirs.
In this way, the father of the family in the absence of a descendant (either a man or a woman), to fully transmit all patrimonial assets and designate an heir and a usufructuary thereof, could adopt a third party (a member of another family that will have numerous children and that will give up one of them for adoption), a foreigner, or, exceptionally, a slave, who, to obtain their freedom or modify their personal and civil status, had to compensate the adopter economically.
The adoption also had a religious character, since in the absence of descendants the adoption served to perpetuate the domestic cult of the ancestors, perform their funeral obsequies, and ingratiate themselves with the gods (redeem the sins of the deceased) through offerings and sacrifices, especially taking into account the role played by family deities in the protection of the community.
Rules were already written on when an adoption could be dissolved and in which cases it could not. Examples of these cases, respectively, are as follows:
When there was violence on the part of the adoptee towards the adoptive family, they would be returned.
When the adoptee learned the family trade, he was not able to return to his family of origin.
In addition, adoption contracts were written. Within this period, we can differentiate different societies in which the adoption fulfilled some or all of the purposes explained above.
In Babylonian society, the social function of adoption as a contractual figure was patrimonial (transmit assets) and related to succession (institute an heir in the absence of descendants) in its private sphere; in its public sphere, it was eminently religious (perpetuating the domestic cult and externalizing the fiction of creating blood ties to the son who is not blood by nature).
Hammurabi’s Code, with a compiling and instructive purpose, regulated the duties, rights, and obligations of adopters and adoptive children. In turn, and in the absence of descendants, gestation contracts allowed the wife (since she was sterile) to provide her husband with an heir through a surrogate or surrogate mother.
In the ancient city of Nuzi (Mesopotamia, present-day Iraq), any type of sale, donation, or commercia transaction of a family patrimonial asset (res extra commercium) was presented under the legal fiction of adoption. Its purpose was patrimonial (transmission of family assets), related to succession (designate an heir), religious (perpetuate domestic worship and carry out funeral obsequies), and private (ordering inter vivos or post mortem services, such as assisting, caring for, and caring for the adopter in his old age).
Lastly, the adoptive institution in Nippur (Mesopotamia, present-day Iraq) did not have a succession purpose but was patrimonial (purchase contract) and eminently social (mobility or ascent of the adoptee on the political, religious, and economic scale). The gestation contracts (as a “reproductive act”) would replace the absence of descendants and heirs since the father of the family and not his wife (as was the case in the city of Nuzi) was the principal party.
2.1.2. Ancient Assyria (Approximately 2025 b.C–609 b.C) and Babylonia (Approximately 1894 b.C.–539 b.C.)
In the case of ancient Assyria and Babylonia, even though a marriage that failed to generate a male son heir could be officially dissolved or a second wife could be taken to bear a son as an heir, the adoption of a child was a common practice (Paulissian 1999
Similar to what happens today, another common reason was the desire of the adoptive parents to have a son/daughter who would support them in their old age and perform the religious rites required upon their death. This was the reason why eunuchs of the royal palace and the females dedicated to religious celibacy also adopted children. However, a craftsman could have adopted a male heir for apprenticeship to guarantee the permanency of the family business (Paulissian 1999
Not many other cultures in the ancient Near East have reported on adoption. For example, there is no evidence of adoption in the Hittite Empire (Vromans 2017
2.2. Ancient Egyptian Society (Approximately 3200 b. C–31 b.C.)
Egyptian law codes are not known; however, there are pieces of evidence indicating their existence. The presence of adoption in Egyptian law can only be endorsed by support from legal written sources. It is clear from these scarce literary examples that direct lineage heritage was very important to Egyptian culture, and succession was the main motive for adoption (Teeter 2017
; Vromans 2017
). As an example, a letter refers to the scribe Nakhtemmut as having “poor character”: “he is “not like a human being” because he has not caused his wife to become pregnant “like his fellow men. (…) And what is worse, he has not even adopted an orphan to remedy the situation” (Teeter 2017
). Adoption in Egypt was not only a way to add to one’s family, but, legally, it was an accepted way to pass an inheritance of goods (or even high office) to someone who was not in the direct line of descent, and so in some cases adoption had nothing to do with fertility (Teeter 2017
). This tradition was verified in ancient Egyptian society, at least until the year 639 A.D., when Amr ibn al-As conquered Egypt and, presumably, prohibited adoption.
The studies and investigations that have been carried out in the different archaeological sites of the Egyptian Empire and analyses of the papyrological, normative, and literary documentation present in the historical archives certify the presence of the adoptive institution during the last stage of the Old Kingdom of Egypt for dynastic purposes, political and religious. Before this stage, no reference was found in this civilization that proves the existence of the adoptive institution.
This conclusion was reached by the discovery of the French archaeologist Georges Legrain of a series of adoptive stelae, which give off a significance of adoptive paternity in the religious and dynastic context of the ancient Egyptian civilization of adoption to enthrone the “Divine Worshipers” of the Dynastic god Amon-Ra (among other deities). Through adoption, the political power and tacit hegemony of the city were ensured over the rest of the territories of Egypt (it was an instrument of political domination and dynastic consolidation). It was also considered that adoptive paternity during the Old Kingdom of Egypt had a patrimonial and succession purpose (compatible with its religious, political, and dynastic nature); the adoptee did not lose the ties that united him with his natural family and preserved his name and rights to the succession of his father by nature.
During the Ptolemaic dynasty, in the late stage of the historical period of Greco-Roman domination we find a series of manuscripts and documents written on papyrus that confirm the legal nature and contractual nature of adoption in Egypt by allowing a third party to, whether a man or a woman, a relative or a stranger, submit a minor under their power through the contractual figure of adoption.
In all the adoption contracts analyzed, a series of clauses were stipulated regarding the obligatory nature of the adopter to raise the minor that they were going to adopt, take care of them, educate them, and establish them as heir to the family patrimony upon their death.
2.3. Ancient Greek Society (Approximately 1200 b.C.–146 b.C.)
Adoption is an important institution in Greek life. Greek marriages were characterized by endogamy, probably to maintain the integrity of Estates, which were transmitted by inheritance through the male line. In order to succeed in an Estate, an heir needed to be recognized as the deceased’s legitimate descendant. Either a natural or an adopted son could inherit without further objection (Lindsay 2010
The original aim of adoption was thought of as a device to ensure succession in the male line when there were no legitimate male heirs. The consequence of such an arrangement was that the adoptive son inherited all his father’s possessions and had to maintain his social and religious obligations just like an authentic son. Generally, in fourth-century cases at Athens, an adopted son was selected from near relatives. There was a preference for the adoption of agnatic relatives. Moreover, it was common to adopt a son or sons for marriage to the biological daughter or daughters.
Inheritance seems central, and it is significant whether or not the adopter died with legitimate sons. If there were none, the adoptive son became the heir, also assuming debts and other obligations related to the role. If there were other children, born later than the adoption, then the adopted son would receive a daughter’s share (Lindsay 2010
Athenian adoptions of the fourth century b.C. appear to have the same focus as those of the fourth century b.C during the high Classical period. Adoption enabled a rich person without descendants to continue his line and to ensure that his interests were protected in old age. In the case of both Greece and Rome, adoption appears to have been, essentially, for the rich people (Lindsay 2010
Models of Adoption in Ancient Greece
In ancient Greece and its city-states, two different models of social, civil, and family organization coexisted: the oligarchic and martial system of Sparta as opposed to the model of Athens and the Cretan city of Gortyna.
In the Spartan model, due to the characteristics of its iron sociopolitical organization (in which all children were the property of the State that was in charge of their education, upbringing, and guardianship with the intent to form vigorous, obedient, and courageous soldiers), adoption was not contemplated as a social institution and filiation or kinship was dependent on the family, whose social function was eminently reproductive and economic.
Education was based on discipline, obedience, and uniformity. Citizenship rights were obtained by the mere fact of being born in Sparta, but full citizenship was only achieved after passing different degrees, such as joining the army (with the category of citizen-soldier), accessing a plot of arable land, or contributing to banquets for social or religious groups (Baelo Álvarez 2013
2.4. Ancient Roman Society (Approximately 753 b.C.–476 a.C.)
In Rome, the term was adoption
, which also comprehended adrogatio
when an adult was adopted as a son homo sui juris
that was not in the power of his parent or was himself a paterfamilias. Both adoption and adrogatio
gave the adopted individual the same obligations and privileges as a birth child, and they were legally entitled to inherit and carry on the family name (Eugena 2015
). In Rome in the first century A.D., a prosperous but childless adult who wanted an heir would adopt a postpubescent male, often a slave, to be his son (Andrews 2004
). Indeed, adoption was practiced as a way of securing an heir in ancient Rome. The emperor Trajan, for example, adopted Hadrian, who succeeded him as emperor in 117 A. D. Octavius Augustus was the adopted heir of Julius Caesar (posthumously adopted) through the process of adrogatio
. He was Caesars’s nephew. Other adopted Roman emperors were Tiberius, Caligula, Nero, Antoninus Pius, Marcus Aurelius, Hadrian, and Trajan (Mitchell 2007
; Eugena 2015
). In the case of politicians, adoption worked also as a technique that enabled the different ideologies of succession to coexist for hundreds of years. Indeed, adoptions often seem to have happened simultaneously with the newly adopted son being married to a biological daughter of the family, at least in the case of imperial adoption practices (Mitchell 2007
). Although there is very little evidence of this practice occurring with consistency among the poorer classes, this type of adoption system was a tactic frequently employed by the imperial families (Mitchell 2007
According to Eugena
), firstly, only men could adopt according to their paterfamilias status. This changed later (second century A.D.), and women were also permitted to adopt.
According to Mitchell
), although sporadically employed by Byzantine emperors, it seems to have disappeared in the West once the Germanic kingdoms replaced the Roman imperial administration.
2.5. Ancient Muslim Societies
Children could also be received into a family by a form of adoption known as “acknowledgement of parenthood”. If there were already children in the family unit, the adopted child could not inherit family property (Mitchell 2007
5. Archaeological Sites with Related and Unrelated Individuals
At this point, we will talk about specific archaeological sites in which genetic analyses have been carried out, and it has been seen that in the same tomb we found biologically related and unrelated individuals. For the analyses, European sites from different prehistoric periods have been selected, which are characterized by having established family relationships between individuals. The sites had a large number of familiar related individuals and also individuals with no known biological relationships. With these examples, we show that being in the same grave does not strictly refer to a family nucleus.
Among the recent works on the establishment of family relationships between Neolithic individuals, that of Fowler et al. 2022 stands out. In this article, they analyzed 35 individuals in an Early Neolithic Tomb from Britain (Hazleton North). The tomb was dated to 3700 BC. A pedigree that integrated 27 individuals in 5 generations was built out of ancient DNA data. One male progenitor had five children with four women. There were eight individuals without evidence of biological relation in the first or second degree. The authors considered that “kinship may not have been the only criterion for inclusion in the tomb
”. Some or all individuals could have been buried in the same tomb by association, co-residence, or adoption (Fowler et al. 2022
). Moreover, three males were not descendants of the principal male but were biological sons of women who had other children with him or his male-line genetic descendants. The authors concluded that these individuals could have been adopted. In this case, the concept of adoption refers to individuals who only share one parent. In this example, we can find signs of family burials such as separate tombs for each family in a community.
In the article of Schroeder et al.
), again in Neolithic individuals in Koszyce (southern Poland), a study was carried out in a mass grave associated with the Globular Amphore Culture (3300–2700 BCE). In this case, 15 individuals (men, women, and children) were found with signs of blows to the head. It is striking how carefully the bodies were placed according to their family relationships (Figure 3
). Thus, the mothers were buried with their children. There is an adult woman, between 30 and 35 years old, who does not appear to be genetically related to any individual in the tomb. She presents a completely different mitochondrial DNA profile from the rest of the individuals in the tomb. She is buried near a 16–17-year-old individual. This raises the fact of adoption, but there is the possibility of other situations, such as the question of whether she is his partner or his partner died during the attack.
Obtained data seem to suggest that Neolithic societies in Central Europe followed a patrilineal model with female exogamy (Haak et al. 2008
; Knipper et al. 2017
). Moreover, most adult males of the group are not in the grave. Can it be that the woman was adopted by this family, and the next man is a relative? These are questions that cannot be answered with actual data.
Regarding the Bronze Age, Mittnik et al.
) studied farmstead-related cemeteries in South Germany from the period between the Late Neolithic period and Middle Bronze Age. In the analysis of 14 sites that correspond to the Corded Ware Complex, Bell Beaker Complex, Early Bronze Age, and Middle Bronze Age, it was observed that the established biological relations in first- and second-degree corresponded to individuals buried together. DNA analysis seems to indicate that these are patrilineal societies with female exogamy. Moreover, it is observed that the males who do not belong to the main line do not have close relatives buried with them. In one of the sites (Haunstetten-Postillionstraβe) corresponding to the Early Bronze Age, nine individuals were identified that could belong to the same genealogy spanning four or five generations, with every male sharing the same Y chromosome haplogroup. Six family members were buried close together in the northern part of the cemetery. All individuals sampled from the northern group with a metal pit are biologically related to each other. However, there is a tomb of a woman with the same funerary characteristics as the previous ones and close to them, although biologically unrelated. Therefore, in addition to family relationships, there may be other criteria when burying individuals in nearby graves.
As we have been able to observe, adoption is an activity that has been carried out since the first civilizations and has occurred in different cultures and times. We do not know how often it occurred in different societies, but it must have been on a regular basis for there to be laws and writings to regulate it. In each of the times and cultures, it occurred for different reasons or purposes, either to continue a line of succession or as a way to avoid discrimination against a woman or couple when they could not conceive. Although we do not know how often adoption occurred in different societies, it can be intuited that, due to the creation of norms and laws that regulate it, the frequency of adoption cases would have been significant. So, when interpreting the results obtained after the analysis of a tomb, the possibility of adoption must be considered. As observed in this review, there are very few studies in which this possibility is contemplated.
We assume that we will handle the adoption hypothesis when we find an archaeological site in which the vast majority of individuals have a genetic family relationship and there are a few individuals whose genetic analysis demonstrates an absence of biological bond, although they were all buried together, or when we observe children buried with adults without any biological link between them. To carry out the kinship study, we must choose the genetic analysis that best suits our samples or the information we want to verify. An example can be an archaeological site in which we only find women and children, in which case we would be interested in analyzing the mtDNA to find out if there is any maternal relationship between them, such as mother–children or grandmother–grandchildren. In the case of males, we will analyze the Y chromosome to admit or discard a paternal lineage between them.
One of the main problems that we can find when carrying out this research is the genetic analysis of the samples. The samples are critical, since they have low concentrations of DNA and this will be of poor quality. In addition, they are samples that are usually found buried directly in the ground, which makes the degradation of biological materials more pronounced. This makes the work of extracting and amplifying DNA and trying to obtain enough genetic material to carry out the analyses complex, as mentioned in the review. Very efficient DNA extraction methods should be used, taking care of contamination with exogenous DNA. Once the genetic analysis has been carried out and the kinship relationships that exist between the individuals can be seen, we can find several problems in the following hypothetical situation of a prehistoric site: For example, we found a site of 11 individuals in the same grave. The placement of the bodies was performed with special care in placing women and children together in contact, and in other stratigraphic levels of the tomb we found men together with ornamentation and vessels; in addition, this tomb is near some remains of what was a house.
The main problems that we can find in this fictitious example are as follows:
The concept of family is something that has occurred in different ways in different cultures since there are different concepts of what the family unit was in addition to the way we know it today. An example of a current family in Western Europe is parents, grandparents, children, and uncles; our neighbors do not belong to that family unit, no matter how good a relationship we have with them. As discussed in point 3.2, this can be observed in African tribes where all the individuals of the tribe, whether or not they are genetically related, are treated as a family unit. This can lead us to confusion when it comes to finding unrelated individuals, since perhaps what we think is an adopted child is a child from another family who had a very close relationship with the family found at the site or the partner of one of the individuals with whom they would not have had offspring yet. In these last two cases, we cannot talk about adoption cases.
For this reason, when carrying out the genetic analysis of a burial, if we find that there is no biological kinship between some individuals, it may let us suppose the adoption hypothesis or the hypothesis of other family interpretations where individuals do not need to have a biological bond to belong to the same family. For this reason, an in-depth study of the type of society in which the site occurs is always very important, as well as the burial place period.
It is possible to find, as mentioned in previous examples, cases in which children of other previous couples are found, but in this case we will find a biological relationship with at least one of the adults and it will not be taken into account as adoption.
Although this review may have many unknowns and variables that cannot be controlled because we are studying human remains of the past, an exhaustive study of the type of society that existed at that time and place can elucidate many of these unknowns and thus be able to ensure with greater certainty a fact of adoption in an archaeological site.
Although genetic study helps to rule out biological relationships or to establish them with a precision that cannot be achieved with any other technique, whether or not there is a case of adoption cannot be answered only with the information we obtain from the genetic study. That is why the adoption study should be multidisciplinary but not exclude genetics. A hypothesis must be elaborated based on the cultural background of the site, referring to all the information on the types of family sites and the rituals and cultures that occurred at the times in which the site is dated, because only then can conjectures be created that can be deciphered with the help of genetics.
This type of study is simplified when at a site we find the so-called tombstones, also called stelae
, whose function is to identify the buried person(s) in the grave. Remains of tombstones have been found that are associated with the graves of the Kurgan culture (which includes a wide variety of communities originating from the steppes of the middle and lower Volga, Russia) from about five thousand years ago. Inscriptions were also found on stone and wooden tombstones on mounds dating back to the Bronze Age. The Greeks buried commoners and elites in inscribed tombs. Likewise, in the pre-Roman city of Vulci (Italy) abundant Roman tombs have been found with statues, reliefs, and inscriptions that tell stories (Saša 2022
). This extra information can help us to more accurately locate the remains that we can find in the tomb and discover what relationship they have between them.
In addition, as mentioned in the PhD Thesis by Gomes et al.
) and also mentioned in Section 3.2
, it was normal for deceased individuals to be buried individually in a sacred place or place of worship, but we see that in the following periods of collective burials the sacred places, such as a cathedral or funeral as an example, began to have limited space. Here, the individuals would begin to be buried individually, but due to lack of space already occupied tombs would have to be used; hence, the tombs already used are completed with individuals of the family.
The task of identifying adoption cases becomes simpler as we get closer to the current dates since we find more information in the deposits. This information can be in the form of the tombstone, knowledge about the society, or the types of funeral rituals they performed. Hence, multidisciplinarity is important when studying a possible case of adoption.
Finally, we want to highlight the importance of knowledge of past societies for the genealogy of families, for example, in discovering a succession chain of emperors of ancient Rome in which none of the heirs to the throne belonged to the family genetically but rather were adopted by the emperor’s family as worthy candidates for power (Juan and Del Mar 2021