Mona Monkey, Cercopithecus mona
A research paper dealing with the evolution of a widespread species of African monkey, the Mona Monkey, Cercopithecus mona, illustrates several mechanisms by which a species can diversify and speciate, and gives the lie to the Creationist claim that the Theory of Evolution is a theory in crisis.
The reality is that the TOE is the foundation of modern biology and the only theory that explains the observed facts. Creationist frauds like to tell their dupes that it's about to be overthrown by some flavour of Bible-literalist fundamentalist creationism or other to make them feel intellectually superior to 'mad' scientists with their 'false' theories and wacky ideas.
A) Image of typical Cercopithecus mona taken at Osun-Osogbo Sacred Grove protected area.
(B) Comparative genomics analysis among C. mona and six related primates. Node bars refer to 95% confidence intervals of divergence time and blue triangles indicate fossil-based calibration points
(B) Comparative genomics analysis among C. mona and six related primates. Node bars refer to 95% confidence intervals of divergence time and blue triangles indicate fossil-based calibration points
Ayoola, Adeola Oluwakemi, Zhang, Bao-Lin, et. al.
From their analysis, the team showed that there had been evolution by:
- Classic Darwinian allopatric speciation. Isolated populations east and west of the River Niger, separated by a physical barrier, evolve according to local environmental factors and genetic drift.
- Introgression and hybridization. The East population showed signs of introgression of genes related to pigmentation.
- Natural selection. Genes involved in immunodeficiency virus defences and malaria resistance showed evidence of being under positive selection pressure.
Some years ago, I wrote an article explaining exactly how this process of divergence and speciation had probably occurred in the African monkeys, as an illustration of how evolution is a process, not an event and why we would not expect to find 'transitional' fossils showing this diversification, or why it can appear to be sudden in the geological record. Here is what I said at the time:
So where and what was the 'speciation event'? At what point in the process could an observer say, "Hey! I've just seen speciation occur! It happened when...". In fact, we only know that speciation has occurred retrospectively because, according to our rules of taxonomy, failure to interbreed means they are now different species. Maybe if we had been able to examine them a hundred thousand years ago, we might have found that they could still interbreed...This open access paper vindicates everything I said in that post. Although appearing in the March 2021 edition of the journal Molecular Biology and Evolution, it was published online in September 2020.
There was no sudden emergence of a new species; no sudden branching of the 'tree of life'; no mutation which brought a new species into being and no 'macro-evolution' event. There was no event which creation pseudo-scientists proclaim to be impossible and which they claim has never been seen. All there was was a slow accumulation of difference, directed by natural selection with each group doing nothing but struggling to survive and reproduce with the ones which left the most descendant contributing the most genes to the gene-pool.
AbstractAnd yet another scientific paper gives the lie to the Creationist claim that the TOE is a theory in crisis. As a reading of this research shows, it is the bedrock of biology as the only theory capable of explaining the diversity we see in nature, and it has the major benefit of not relying on magic and mysteries. It also reinforces the constant biologist refrain:
Guenons (tribe Cercopithecini) are the most widely distributed nonhuman primate in the tropical forest belt of Africa and show considerable phenotypic, taxonomic, and ecological diversity. However, genomic information for most species within this group is still lacking. Here, we present a high-quality de novo genome (total 2.90 Gb, contig N50 equal to 22.7 Mb) of the mona monkey (Cercopithecus mona), together with genome resequencing data of 13 individuals sampled across Nigeria. Our results showed differentiation between populations from East and West of the Niger River ∼84 ka and potential ancient introgression in the East population from other mona group species. The PTPRK, FRAS1, BNC2, and EDN3 genes related to pigmentation displayed signals of introgression in the East population. Genomic scans suggest that immunity genes such as AKT3 and IL13 (possibly involved in simian immunodeficiency virus defense), and G6PD, a gene involved in malaria resistance, are under positive natural selection. Our study gives insights into differentiation, natural selection, and introgression in guenons.
Introduction
African nonhuman primates are exceptionally diverse, yet knowledge on their genetics, behavior, and ecology is largely limited, which has hindered their conservation and utilization as human disease models. In Africa, guenons (tribe Cercopithecini) are one of the most diverse groups of nonhuman primates and show great variation in ecology, behavior, and morphology. Several factors have been illustrated as potential drivers in the evolutionary radiation of guenons (Tosi et al. 2004, 2005). For instance, some guenons are terrestrial, whereas the majorities are arboreal forest-dwellers utilizing different forest canopy levels in sub-Saharan Africa (Gautier et al. 2002). Thus, previous studies (Disotell and Raaum 2002.1; Guschanski et al. 2013) have stated that speciation in guenons may be associated with forest cover change and specifically forest refugia that occurred in the last 10 Ma. Further, hybridization has also been identified as an important mechanism in the evolution of many lineages, including guenons (Allen et al. 2014; Detwiler 2019; van der Valk et al. 2020), which could have resulted in genetic introgression across species.
Among the five genera of this tribe (i.e., Cercopithecus, Miopithecus, Allenopithecus, Erythrocebus, and Chlorocebus), the genus Cercopithecus is the largest, consisting of 26 species that exhibit variation in genetics, morphology, ecology, behavior, and social organization (Grubb et al. 2003; Anandam et al. 2013.1; Zinner et al. 2013.2). Previous studies based on mitochondrial and nuclear sequences (Tosi et al. 2006) have illustrated their phylogeography and identified several species groups, including the dryas, diana, mitis, cephus, hamlyni, neglectus, and mona groups (Grubb et al. 2003; Chatterjee et al. 2009; Guschanski et al. 2013). The mona species group has attracted growing attention (Oates 2011; Okekedunu et al. 2014.1; Onadeko et al. 2014.2) and is composed of several species or subspecies. Similarly, this group is widely distributed across the African Guineo-Congolian rainforest, with a range extending across Ghana to Cameroon (Oates 2011; Okekedunu et al. 2014.1). Mona group species live in several types of forest areas within urban, peri-urban, and wild populations (Okekedunu et al. 2014.1). They usually coexist in sympatry with other primates and often form polyspecific troops, allowing interspecific or even intergeneric hybridization (Gartlan and Struhsaker 1972; Goodwin 2007). Thus, this group provides an ideal model system to investigate the role of genetic introgression in primate evolution. Thus far, no genomic information has been reported for the mona group, which has made it difficult to delineate the evolutionary history and adaptive evolution of this species group.
The advent of large-scale genome sequencing has facilitated investigations into the evolution and ecology of many wild animals, particularly nonhuman primates (Gibbs et al. 2007.1; Locke et al. 2011.1; Scally et al. 2012; Prado-Martinez et al. 2013.3; Carbone et al. 2014.3; Rogers and Gibbs 2014.4; Worley et al. 2014.5; Rogers et al. 2019.1; Zhang et al. 2019.2; van der Valk et al. 2020). Herein, we de novo assembled the genome of Cercopithecus mona and utilized large-scale genomic data to investigate population differentiation, demographic history, natural selection, and genetic introgression in this species. Interestingly, population genomic analyses revealed a divergence between the East and West Central (WC) populations ∼84 ka and identified several immunity genes under positive natural selection. We also found some genes related to pigmentation displaying signals of genetic introgression in the East population from an unknown species. This study should help improve our understanding of the evolution and genetics of the African mona species group.
Ayoola, Adeola Oluwakemi; Zhang, Bao-Lin; Meisel, Richard P; Nneji, Lotanna M; Shao, Yong; Morenikeji, Olanrewaju B; Adeola, Adeniyi C; Ng’ang’a, Said I; Ogunjemite, Babafemi G; Okeyoyin, Agboola O; Roos, Christian; Wu, Dong-Dong
Population Genomics Reveals Incipient Speciation, Introgression, and Adaptation in the African Mona Monkey (Cercopithecus mona)
Molecular Biology and Evolution; 38 (3). 876–90. doi:10.1093/molbev/msaa248.
Copyright: © 2020 The authors. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. Open access.
Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)
Where does one color change into another?
Evolution is a process, not an event,
so why demand evidence of an event?
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Evolution is a process, not an event,
so why demand evidence of an event?
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