Evolutionary Trajectories of Complex Traits in European Populations of Modern Humans

Abstract

Humans have a great diversity in phenotypes, influenced by genetic, environmental, nutritional, cultural, and social factors. Understanding the historical trends of physiological traits can shed light on human physiology, as well as elucidate the factors that influence human diseases. Here we built genome-wide polygenic scores for heritable traits, including height, body mass index, lipoprotein concentrations, cardiovascular disease, and intelligence, using summary statistics of genome-wide association studies in Europeans. Subsequently, we applied these scores to the genomes of ancient European populations. Our results revealed that after the Neolithic, European populations experienced an increase in height and intelligence scores, decreased their skin pigmentation, while the risk for coronary artery disease increased through a genetic trajectory favoring low HDL concentrations. These results are a reflection of the continuous evolutionary processes in humans and highlight the impact that the Neolithic revolution had on our lifestyle and health.

Evolutionary Trends of Polygenic Scores in European Populations From the Paleolithic to Modern Times

“…However, the study had limitations due to its small sample size (N = 99). Kuijpers et al (2022), with a larger sample of ancient genomes, confirmed these findings and observed an evolutionary acceleration post-Neolithic. Notably, their research depended on what was then an older PGS for education from Okbay et al (2016).…”

“…Our analysis includes adjustments for ancestral background and geographic location. This study expands upon Kuijpers et al (2022) by using a GWAS based on a much larger sample (3 million individuals compared to 293,000) and focusing on different genetic traits. Unlike Kuijpers et al, we exclude medical phenotypes like lipoprotein levels and cardiovascular disease, instead incorporating mental health traits such as neuroticism, autism and schizophrenia.…”

Genetic Predisposition of Atherosclerotic Cardiovascular Disease in Ancient Human Remains

“…Previous studies have begun to explore the evolution of various complex traits by using ancient DNA [ 22 43 ]. In contrast to our investigation, these studies were based on pseudo-haploid genomes in which only one of the two alleles at each locus was randomly selected for evaluation.…”

“…In these cases, the true allele frequency is obscured, and the absence of a mutation can be artificially created. Recently, Kuijpers and colleagues used this method to show that HDL levels, an antagonist of atherogenesis, decreased consistently in European populations after the Neolithic Revolution [ 22 ]. However, in contrast to our study, they were not able to compare their genetic results with real phenotypes and the PRSs were calculated only for a haploid state.…”

“…In mummies, the soft tissue is often sufficiently preserved to examine organs or arteries for diseases that have left no traces on the skeleton [ 21 ]. Another reason is that most available genotypes from ancient individuals are pseudo-haploid as a consequence of low genotyping coverage [ 22 ]. Ancient DNA (aDNA) is highly fragmented and prone to contamination.…”