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Creationists will confidently tell you that a loss of genetic information is invariably fatal so can play no part in evolution. They believe this because the frauds at the Discovery Institute have misled them into believing that every piece if DNA and therefore every piece of genetic information has a purpose.
And yet researchers have shown that it was a loss of genetic information following a population bottleneck that gave rise to the classic Neanderthals as a distinct species from their pre-Neanderthal ancestors.
This was the conclusion from a study led by Alessandro Urciuoli (Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona) and Mercedes Conde-Valverde (Cátedra de Otoacústica Evolutiva de HM Hospitales y la Universidad de Alcalá), researchers measured the morphological diversity in the structure of the inner ear responsible for our sense of balance: the semicircular canals.
What is known about the evolutionary origins of the Neanderthals? The evolutionary origins of Neanderthals (Homo neanderthalensis) can be traced back to the divergence between the ancestors of Neanderthals and modern humans (Homo sapiens), which likely occurred between 600,000 and 800,000 years ago. Neanderthals are generally considered to have evolved from populations of Homo heidelbergensis or a closely related species in Eurasia. Here's a breakdown of their evolutionary history:The study involved the examination of fossil samples from Atapuerca (Spain) and Krapina (Croatia), as well as from various European and Western Asian sites. The results have been published in Nature Communications and are explained in an Institut Català de Paleontologia news item:
Neanderthals were not a dead-end species but contributed to the genetic makeup of modern humans, leaving a lasting evolutionary legacy.
- Ancestry and Divergence from Modern Humans
- Genetic and fossil evidence suggests that Neanderthals and modern humans share a common ancestor, often identified as Homo heidelbergensis or Homo antecessor.
- The split between the lineages leading to Neanderthals and modern humans likely occurred before 600,000 years ago.
- The Neanderthal lineage remained in Europe and western Asia, while the modern human lineage evolved in Africa.
- Early Neanderthal Evolution (≈600,000–400,000 years ago)
- Fossils from Europe, such as those from Sima de los Huesos in Spain (~430,000 years old), exhibit traits that are intermediate between H. heidelbergensis and later Neanderthals.
- The Denisovans, an enigmatic sister group to Neanderthals, also branched off from this common ancestor.
- Classic Neanderthals (≈250,000–40,000 years ago)
- By about 250,000 years ago, Neanderthals had developed their characteristic features, including:
- A large brain (on average larger than that of modern humans).
- A robust skeleton adapted for cold climates.
- Distinctive facial features such as a large nose and pronounced brow ridges.
- They spread across Eurasia, from western Europe to Siberia and the Middle East.
- Interbreeding with Other Humans
- Neanderthals interbred with early modern humans when the two populations encountered each other.
- Genetic studies show that non-African modern humans carry about 1-2% Neanderthal DNA, indicating interbreeding between Neanderthals and Homo sapiens around 50,000–60,000 years ago.
- Extinction (~40,000 years ago)
- Neanderthals disappeared from the fossil record around 40,000 years ago, likely due to a combination of factors:
- Climate change.
- Competition with Homo sapiens.
- Small, isolated populations leading to inbreeding and genetic decline.
Can you briefly explain how examining the morphology of the semicircular canals in the inner ear can contribute to our understanding of this evolution?
Examining the morphology of the semicircular canals in the inner ear provides valuable insights into the locomotion and ecological adaptations of Neanderthals and their ancestors. The semicircular canals, part of the vestibular system, are crucial for balance and movement coordination, and their shape and size can reflect differences in locomotor behaviour among hominin species.
How It Contributes to Understanding Neanderthal Evolution:In short, semicircular canal morphology helps reconstruct how Neanderthals moved and adapted to their environments, shedding light on their evolutionary divergence from modern humans.
- Locomotion and Posture:
- The semicircular canals influence an organism’s ability to balance during movement.
- Comparisons between Neanderthals and modern humans show that Neanderthals had slightly different canal proportions, possibly reflecting a more rigid, less agile movement style, suited for rough terrain.
- Adaptation to Environment:
- Neanderthals evolved in colder, forested, and mountainous regions, where stability and endurance were likely more crucial than rapid directional changes.
- Differences in canal morphology suggest they may have had a lower agility compared to early modern humans, aligning with their robust, stocky build.
- Phylogenetic Relationships:
- By comparing the semicircular canals of Neanderthals, early Homo sapiens, Homo heidelbergensis, and earlier hominins, researchers can infer how locomotion evolved across different human lineages.
- Neanderthal canal morphology shows a closer affinity to earlier European hominins (H. heidelbergensis) than to modern humans, supporting the idea of a long, independent evolutionary trajectory.
The inner ear of Neanderthals reveals clues about their enigmatic origin
New research on the inner ear morphology of Neanderthals and their ancestors challenges the widely accepted theory that Neanderthals originated after an evolutionary event that implied the loss of part of their genetic diversity. The findings, based on fossil samples from Atapuerca (Spain) and Krapina (Croatia), as well as from various European and Western Asian sites have been published in Nature Communications.
Neanderthals emerged around 250.000 years ago from European populations—referred to as "pre-Neanderthals"—which inhabited the Eurasian continent between 500.000 and 250.000 years ago. It was long believed that no significant changes occurred throughout the evolution of Neanderthals, yet recent paleogenetic research based on DNA samples extracted from fossils revealed the existence of a drastic genetic diversity loss event between early Neanderthals (or ancient Neanderthals) and later ones (also referred to as "classic" Neanderthals). Technically known as a "bottleneck", this genetic loss is frequently the consequence of a reduction in the number of individuals of a population. Paleogenetic data indicate that the decline in genetic variation took place approximately 110,000 years ago.
The presence of an earlier bottleneck event related to the origin of the Neanderthal lineage was also a widespread assumption among the scientific community. As such, all hypotheses formulated thus far were based on the idea that the earliest Neanderthals exhibited lower genetic diversity than their pre-Neanderthal ancestors, as consequence of a bottleneck event. However, the existence of a bottleneck at the origin of the Neanderthals has not been confirmed yet through paleogenetic data, mainly due to the lack of genetic sequences old enough to record the event and needed for ancient DNA studies.
In a study led by Alessandro Urciuoli (Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona) and Mercedes Conde-Valverde (Cátedra de Otoacústica Evolutiva de HM Hospitales y la Universidad de Alcalá), researchers measured the morphological diversity in the structure of the inner ear responsible for our sense of balance: the semicircular canals. It is widely accepted that results obtained from studying the morphological diversity of the semicircular canals are comparable to those obtained through DNA comparisons.
Image 1. Schematic representation of the changes in morphological diversity along the evolutionary history of the Neanderthal clade. Sima de los Huesos and, particularly, Krapina populations show similarly large amounts of morphological variation, thus suggesting continuity during the Middle Pleistocene. Later, classic Neanderthals instead appear much less diverse, hence hinting for the presence of a drop in phenotypic variation right after the temperature maximum reached around 120.000 years ago, and at the beginning of the Last Glacial cycle.
The study focused on two exceptional collections of fossil humans: one from the Sima de los Huesos site of Atapuerca (Burgos, Spain), dated to 430,000 years old, which constitutes the largest sample of pre-Neanderthals available in the fossil record; and another from the Croatian site of Krapina, this representing the most complete collection of early Neanderthals and dated to approximately 130.000-120.000 years ago. The researchers calculated the amount of morphological diversity (i.e., disparity) of the semicircular canals of both samples, comparing them with each other and with a sample of classic Neanderthals of different ages and geographical origins.
The study's findings reveal that the morphological diversity of the semicircular canals of classic Neanderthals is clearly lower than that of pre-Neanderthals and early Neanderthals, which aligns with previous paleogenetic results. Mercedes Conde-Valverde, co-author of the study, emphasized the importance of the analyzed sample: “By including fossils from a wide geographical and temporal range, we were able to capture a comprehensive picture of Neanderthal evolution. The reduction in diversity observed between the Krapina sample and classic Neanderthals is especially striking and clear, providing strong evidence of a bottleneck event.”
On the other hand, the results challenge the previously accepted idea that the origin of Neanderthals was associated with a significant loss of genetic diversity, prompting the need to propose new explanations for their origin.We were surprised to find that the pre-Neanderthals from the Sima de los Huesos exhibited a level of morphological diversity similar to that of the early Neanderthals from Krapina. This challenges the common assumption of a bottleneck event at the origin of the Neanderthal lineage
Dr. Alessandro Urciuoli, lead author.
Universitat Autònoma de Barcelona
Barcelona, Spain.
Alessandro Urciuoli is a postdoctoral fellow at the University of Zurich (previously employed at the Universitat Autònoma de Barcelona as a Margarita Salas postdoctoral fellow) and associated researcher at the Institut Català de Paleontologia Miquel Crusafont; Mercedes Conde-Valverde is lecturer at the Universidad de Alcalá and director of the Cátedra de Otoacústica Evolutiva de HM Hospitales and the Universidad de Alcalá.
Publication
Urciuoli, A., Martínez, I., Quam, R., Arsuaga, J. L., Keeling, B. A., Diez-Valero, J. & Conde-Valverde, M. (2025).
Semicircular Canals Shed Light on Bottleneck Events in the Evolution of the Neanderthal Clade.
Nature Communications. https://doi.org/1038/s41467-025-56155-8
AbstractNeanderthals are a major headache for creationists for several reasons, and this finding that 'classic' Neanderthals were the result of evolution by loss of genetic information is just one of them.
Revealing the evolutionary processes which resulted in the derived morphologies that characterize the Neanderthal clade has been an important task for paleoanthropologists. One critical method to quantify evolutionary changes in the morphology of hominin populations is through evaluating morphological phenotypic diversity (i.e., disparity) in phylogenetically informative bones as a close proxy to neutral evolutionary processes. The goal of this study is to quantify the degree of disparity in the Neanderthal clade. We hypothesize that a reduction in bony labyrinth disparity is indicative of the underlying genetic variation resulting from bottleneck events. We apply a deformation-based geometric morphometric approach to investigate semicircular canal and vestibule shape of a chronologically broad sample of individuals belonging to the Neanderthal lineage. Our results identify a significant reduction in disparity after the start of Marine Isotope Stage 5 supporting our hypothesis of a late bottleneck, possibly leading to the derived morphology of Late Pleistocene Neanderthals.
Fig. 2: Scenarios of phenetic variation along the evolution of the Neanderthal clade.
a Scenario #1: no occurrence of bottleneck events; b Scenario #2: occurrence of an early bottleneck event between Sima de lo Huesos and Krapina populations; c Scenario #3: occurrence of a late bottleneck event after population of Krapina and before late Neanderthals; d Scenario #4: occurrence of both an early and late bottleneck events. The horizontal line is a schematic representation of time with earlier occurring groups on the left and later occurring ones on the right. The thickness of the horizontal bars corresponds to the suggested phenetic variation. Colors are coded as follows: blue = Sima de los Huesos; purple = Krapina; green = late Neanderthals.
Fig. 3: Bivariate scatterplots of a principal component analysis performed on the deformation-fields (raw shape data) obtained from the diffeomorphometric analysis of semicircular canals.
a PC2 vs. PC1; b PC4 vs. PC3. The variance explained by each PC is given within parentheses. 95% confidence ellispes, symbols, and c–f group average shapes (in posterolateral and posteromedial views) are color-coded based on group membership: blue = Sima de los Huesos; purple = Krapina; green = late Neanderthals; orange = modern humans. Source data for this figure can be reproduced using the code and files provided in Supplementary Code 1 and Supplementary Data 3.
Fig. 4: Shape and size differences.
Frequency plots of morphological variance (a) and disparity (b) for each group in the semicircular canal shape space. Bootstrapped group distributions (20,000 bootstraps) were computed based on PC1-19 scores (86.7% of variance) to account for the small number of available specimens for fossil groups. The solid lines represent density curves of the frequencies for morphological variance and disparity values between all possible pairs of individuals within each bootstrapped group. The vertical axis represents the frequency of a given disparity or variance value obtained from the bootstrapping of the sample. Vertical dashed lines correspond to group averages for morphological variance and disparity. c Line plot of pair-wise Euclidean distances for the bootstrapped group distribution (20,000 bootstraps). The solid line corresponds to the second and third quartile; dashed lines represent first and fourth quartiles; black dot shows median of the distribution. d Natural logarithm (ln) of the centroid size of semicircular canals for the individuals included in the analysis. Classic Neanderthals display the largest size variation together with modern humans. Color coding as in Figs. 1 and 3. Source data for this figure can be reproduced using the code and files provided in Supplementary Code 1 and Supplementary Data 3.
Urciuoli, A., Martínez, I., Quam, R. et al. Semicircular canals shed light on bottleneck events in the evolution of the Neanderthal clade. Nat Commun 16, 972 (2025). https://doi.org/10.1038/s41467-025-56155-8
Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
They also lived several thousands of years before creationism's god created the Universe according to their favourite mythology; and, by contributing their DNA to modern Eurasian Homo sapiens, they refute the childish notion of a single founder couple who did the 'Original Sin' that we all need forgiveness and redemption for, allegedly. Not only was there not a single founder couple; there was not even a single founder species.
No wonder one of their favourite lies is that all we know about Neanderthals is from a single specimen which has been shown to be a modern human with arthritis. In fact, roughly 500 individual Neanderthals have been recovered from over 200 sites in western Eurasia spanning a time range of 400,000 to 40,000 years ago. Certainly enough to show evolutionary change over time, as this paper demonstrates.