Creationism in Crisis - An Acute Bottleneck in Early Hominin Ancestral History - Almost a Million Years Ago

The core formula of the new inference method is shown. The image depicts a cliff painting, illustrating the population of human ancestor pull together to survive the unknown danger in the darkness during the ancient severe bottleneck.

Image by Shanghai Institute of Nutrition and Health, CAS

Early Ancestral Bottleneck Could’ve Spelled the End for Modern Humans----Shanghai Institute of Nutrition and Health, Chinese Academy of Sciences

African savannah in the Middle Pleistocene (Artist's Impression)

Credit: Peter Schouten

Creationists claim, without any understanding of the biological absurdity of the claim, that the human population on Earth went through a genetic bottleneck of 8 related individuals about 4,000 years ago following a genocidal flood inflicted on Earth by an angry god, annoyed that his design wasn't working as intended.

The one thing right about that claim is the bottleneck, although it wasn't so narrow that it would have almost guaranteed extinction within a few generations because of accumulated deleterious genes and a lack of genetic diversity, it was about 1,280 individuals and it happened about 900,000 years before creationists believe the universe was created, before anatomically-modern humans had evolved.

This is the findings of Chinese researchers led by Haipeng Li, of the Chinese Academy of Science (CAS) Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, and Yi-Hsuan Pan of the Key Laboratory of Brain Functional Genomics of Ministry of Education, School of Life Science, East China Normal University, Shanghai, China.

First, a little about evolutionary bottlenecks and the consequences for humanity had the mythical genocidal flood actually occurred as creationists believe:

How does a narrow population bottleneck affect the evolution of a species and what would be the most likely outcome if the human population was reduced to a husband and wife, their three sons and their wives?

A narrow population bottleneck occurs when a species' population is dramatically reduced to a very small number of individuals, which can have significant and long-lasting effects on the evolution of that species. Here's how it typically affects evolution:

1. Loss of Genetic Diversity: A bottleneck drastically reduces the number of individuals carrying genetic variation within the population. As a result, many alleles (different forms of genes) are lost, leading to a significant reduction in genetic diversity. This can result in the loss of advantageous traits and increase the frequency of harmful mutations.>/li>
2. Increased Genetic Drift: With a small population size, genetic drift, which is the random change in allele frequencies, becomes a dominant force in shaping the population's gene pool. This can lead to the fixation of certain alleles, even if they are not necessarily beneficial or adaptive. Genetic drift can lead to the accumulation of deleterious mutations and reduce overall fitness.
3. Increased Inbreeding: In a small population, there is a higher likelihood of close relatives mating (inbreeding), which can increase the expression of recessive deleterious alleles, leading to a higher frequency of genetic disorders and reduced overall fitness.
4. Reduced Adaptive Potential: The loss of genetic diversity limits the species' ability to adapt to changing environmental conditions or new challenges. A bottlenecked population may be less able to evolve in response to threats, reducing its chances of survival in the long term.
5. Vulnerability to Disease and Environmental Changes: Small populations are more vulnerable to diseases and environmental changes because they lack the genetic diversity necessary to mount effective responses to new pathogens or environmental stresses.

Now, let's consider the hypothetical scenario where the human population is reduced to a husband and wife, their three sons, and their wives. In this case, the human population would experience a severe bottleneck event with only 8 individuals. The consequences for the human species would likely include:

1. Loss of Genetic Diversity: With such a small population, a significant portion of human genetic diversity would be lost, making the population highly susceptible to the effects of genetic drift and inbreeding.
2. Increased Genetic Drift: Genetic drift would play a substantial role in shaping the genetic makeup of this small population, leading to the fixation of certain alleles by chance.
3. Increased Inbreeding: Inbreeding would be almost inevitable in this scenario, resulting in a higher risk of genetic disorders and reduced overall health and fitness.
4. Limited Adaptive Potential: The population would have limited genetic resources to adapt to changing environments or new challenges, which could be detrimental in the long run.
5. Vulnerability to Disease and Environmental Changes: The small population size would make it highly vulnerable to diseases and environmental changes, increasing the risk of extinction.

In summary, a narrow population bottleneck can have severe and long-lasting effects on a species, including reduced genetic diversity, increased genetic drift and inbreeding, limited adaptive potential, and increased vulnerability to various threats. If the human population were reduced to just 8 individuals, the species would face significant challenges and risks, including a higher likelihood of extinction in the long term due to these genetic and demographic factors.

Creationists will also claim, believing the only evidence science uses for the Theory of Evolution is the fossil record, that the entire fossil record of human evolution is missing as there are no 'intermediate forms'. In fact, the fossil record is so plentiful that any remaining confusion is how it all fits together, how the different contemporaneous species were related, and which was directly ancestral to which.

For this reason, gaps in the record need explaining and an acute bottleneck such as that described by the researchers, explains just such a gap in the Middle Pleistocene - which coincides with the climatological record of a period of sudden cooling in the African savannah which could have caused such a population crash from an estimated population of about 98,130 individuals.

The research also suggests that this small population never recovered for some 117,000 years, after which it remained at a stable population of about 27,160 for a further 600,000 years, before the evolution of Homo sapiens and the dispersal out of Africa!

The news release from the CAS Shanghai Institute of Nutrition and Health explains the significance of the research:

How a new method of inferring ancient population size revealed a severe bottleneck in the human population which almost wiped out the chance for humanity as we know it today.

An unexplained gap in the African/Eurasian fossil record may now be explained thanks to a team of researchers from China, Italy and the United States. Using a novel method called FitCoal (fast infinitesimal time coalescent process), the researchers were able to accurately determine demographic inferences by using modern-day human genomic sequences from 3,154 individuals. These findings indicate that early human ancestors went through a prolonged, severe bottleneck in which approximately 1,280 breeding individuals were able to sustain a population for about 117,000 years. While this research has illuminated some aspects of early to middle Pleistocene ancestors, there are many more questions to be answered since uncovering this information.

[However], the fact that FitCoal can detect the ancient severe bottleneck with even a few sequences represents a breakthrough

Yun-Xin FU, Senior author
Theoretical population geneticist
Health Science Center
University of Texas at Houston, Huston, Texas, USA.

A large amount of genomic sequences were analyzed in this study.

Researchers will publish their findings online in Science on August 31, 2023. The results determined using FitCoal to calculate the likelihood for present-day genome sequences found that early human ancestors experienced extreme loss of life and therefore, loss of genetic diversity.

The gap in the African and Eurasian fossil records can be explained by this bottleneck in the Early Stone Age as chronologically. It coincides with this proposed time period of significant loss of fossil evidence.

Giorgio Manzi, senior author Anthropologist
Sapienza University of Rome.

Reasons suggested for this downturn in human ancestral population are mostly climatic: glaciation events around this time lead to changes in temperatures, severe droughts, and loss of other species, potentially used as food sources for ancestral humans.

The novel finding opens a new field in human evolution because it evokes many questions, such as the places where these individuals lived, how they overcame the catastrophic climate changes, and whether natural selection during the bottleneck has accelerated the evolution of human brain.

Yi-Hsuan PAN, senior author
Key Laboratory of Brain Functional Genomics of Ministry of Education
School of Life Science
East China Normal University (ECNU), Shanghai, China.

An estimated 65.85% of current genetic diversity may have been lost due to this bottleneck in the early to middle Pleistocene era, and the prolonged period of minimal numbers of breeding individuals threatened humanity as we know it today. However, this bottleneck seems to have contributed to a speciation event where two ancestral chromosomes may have converged to form what is currently known as chromosome 2 in modern humans. With this information, the last common ancestor has potentially been uncovered for the Denisovans, Neanderthals, and modern humans (Homo sapiens). We all know that once a question is answered, more questions arise.

These findings are just the start. Future goals with this knowledge aim to paint a more complete picture of human evolution during this Early to Middle Pleistocene transition period, which will in turn continue to unravel the mystery that is early human ancestry and evolution.

LI Haipeng, senior author
Theoretical population geneticist and computational biologist
Shanghai Institute of Nutrition and Health
Chinese Academy of Sciences (SINH-CAS), shanghai, China

Now that there is reason to believe an ancestral struggle occurred between 930,000 and 813,000 years ago, researchers can continue digging to find answers to these questions and reveal how such a small population persisted in assumably tricky and dangerous conditions. The control of fire, as well as the climate shifting to be more hospitable for human life, could have contributed to a later rapid population increase around 813,000 years ago.

The ancient human population bottleneck and the Out-of-Africa dispersal. The African hominin fossil gap and the estimated time period of chromosome fusion is shown on the right.

Image provided by LI Haipeng’s group.

The other thing coming from this research that creationists might like to ignore, is the complete lack of any evidence of a population bottleneck about 4,000 years ago.

So, for the benefit of any creationists who found the courage to read this far, here are a few of the things you need to ignore from this research:

1. The use the scientists make of the Theory of Evolution in placing this genetic bottleneck in an ancestral species, with no indication that the TOE was inadequate for explaining the facts. Score: creationism 0; science 1.
2. The evidence that there were archaic humans several hundred thousand years before creationists believe there was even a universe. Score: creationism 0; science 2.
3. The evidence of common ancestry in that our genetic history, including the genetic history of an ancestral species, can still be detected in our genome. Hint: this would not be so, if modern humans were specially created without ancestors, the way the biblical creation myth claims. The absence of evidence predicted by a theory is normally accepted as falsification of the theory, whilst the presence of evidence predicted by an alternative theory is normally accepted as evidence for that theory. Score: creationism 0; science 3.
4. The absence of any evidence of an even more drastic population bottleneck just a few thousand years ago, as the myth of the genocidal biblical flood relates. Again, a falsification of the biblical theory. Score: creationism 0; science 4.
5. Corroboration of the theory by a second stream of evidence - climatology - which supplies an explanation for the population collapse and the gap in the fossil record. Score: creationism 0; science 5.
6. The fact that the fossil evidence for human origins in Africa is so rich that palaeontologists regard a gap as evidence that something unusual occurred. Score: creationism 0; science 6.

Overall, another dreadful day for creationism and an explanation for why creationism is a theory in crisis while the TOE goes from strength to strength.

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