Archaeologists analyzing the genetic material of the 300,000-year-old hominin Homo naledi have discovered that all known skeletons of the species are female. This finding, based on proteomic analysis of 20 teeth, is unique in the study of human evolution.<\/p>\n
The Homo naledi species was discovered within a South African cave system as part of the Rising Star project, led by Lee Berger. Since 2013, nearly two dozen skeletons have been unearthed in the Cradle of Humankind. Research has previously highlighted Homo naledi’s unusual characteristics, including a small brain and upper body similar to australopithecines, yet with more human-like faces, hands, and lower limbs. In recent years, the Rising Star team has proposed that Homo naledi may have used fire and potentially buried their dead, behaviors considered complex for a human relative with a small brain.<\/p>\n
The new study, published in the journal Cell, utilized proteomic analysis, a minimally destructive technique that sequences ancient proteins. Researchers focused on amelogenin genes (AMEL), which are involved in dental enamel formation and vary by sex. The AMELX variant is present in both sexes, while AMELY is found only in biological males.<\/p>\n
The analysis of 20 Homo naledi teeth revealed the absence of AMELY proteins, with abundant AMELX proteins detected. This suggests that all the analyzed skeletons, including those previously assumed to be male like Neo and DH1, are female. This is a significant departure from known ancient human cemeteries or collections of nonhuman primate skeletons, which typically include both sexes.<\/p>\n
Lee Berger suggested that the results might indicate cultural selection for burial by sex or gender after death. John Hawks, a paleoanthropologist at the University of Wisconsin-Madison and study co-author, noted that Homo naledi burial sites are older than any known Neanderthal or modern human burial sites, making the possibility of an all-female collection particularly remarkable.<\/p>\n
Paleoanthropologists have expressed surprise at the findings. Elizabeth Sawchuk, curator of human evolution at the Cleveland Museum of Natural History, described the result as “weird” for an “already weird hominin.” She cautioned that the absence of detected AMELY does not definitively prove the absence of males, as a rare gene deletion of AMELY, known in some modern humans and one Neanderthal, could potentially make male and female protein profiles indistinguishable.<\/p>\n
However, study co-author Enrico Cappellini, a professor at the University of Copenhagen, stated that such a deletion being present in even half of the 20 individuals, let alone an entire population, is unlikely. He noted that either the absence of males in the cave system or a systematic AMELY gene deletion would have significant implications for understanding Homo naledi’s biology and evolution.<\/p>\n
The study also revealed that Homo naledi shares a gene variant related to collagen production with Paranthropus robustus, another South African hominin relative. The significance of this shared variant, which differs from genes in modern humans, Neanderthals, and Denisovans, is unclear, as the temporal overlap and relationship between these species remain to be determined.<\/p>\n
Researchers acknowledge that more investigation is needed, and building a larger database of ancient proteins from other African hominins like Australopithecus africanus and Homo erectus could help contextualize these findings and clarify Homo naledi’s place in human evolution. The study also demonstrates the viability of minimally destructive proteomic analysis for investigating extinct hominins.<\/p>\n","protected":false},"excerpt":{"rendered":"
Analysis of 20 Homo naledi teeth suggests all known skeletons of the ancient hominin species are female, a unique finding in human evolution studies. The discovery challenges previous assumptions and raises new questions about the species’ biology and behavior.<\/p>\n","protected":false},"author":3,"featured_media":2239,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":[],"categories":[3],"tags":[1860,2322,2325,2323,2324],"yoast_head":"\n