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Printable Handouts
Navigable Slide Index
- Introduction
- Genetic adaptation
- Genome scans for natural selection
- Humans and infectious diseases
- The red queen race
- Haldane's hypothesis
- Thalassemia & malaria
- Balancing selection
- Trans-specific polymorphisms
- Major histocompatibility complex (MHC)
- Nucleotide diversity at the HLA genes
- Natural selection at the HLA genes
- Spatial variation of allele frequencies
- Pathogen-driven selection driving HLA diversity
- Balancing selection outside the HLA genes
- The innate immune system
- Natural selection on the innate immunity system
- Blood group antigen (BGA) genes
- Variation at BGA genes
- ABO
- FUT2
- Adaptation to local pathogenic environment
- Local adaptation drives population differentiation
- Pathogens have been the main selective pressure
- Viruses and humans co-evolution
- Virus-driven selection
- The case of CCR5 and HIV
- The case of ZC3HAV1 and multiple sclerosis (MS)
- Malaria
- Selection on malaria-resistant variants
- Helminth infections
- Helminth-driven selection and disease
- The hygiene hypothesis
- Natural selection and autoimmune diseases
- From natural selection to functional validation
- Summary
Topics Covered
- Natural selection at the immune system
- Signals of pathogen-driven selection in the human genome
- Human evolution and susceptibility to infectious diseases
- Autoimmune conditions and the hygiene hypothesis
Links
Series:
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Therapeutic Areas:
Talk Citation
Fumagalli, M. (2015, March 18). Human pathogen-driven evolution [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 3, 2024, from https://doi.org/10.69645/CLUI8261.Export Citation (RIS)
Publication History
Financial Disclosures
- Dr. Matteo Fumagalli has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
Other Talks in the Series: Human Population Genetics II
Transcript
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0:00
Hi, my name is Matteo Fumagalli,
and I'm a Research Associate at the UCL Genetics Institute, University College London.
Today, I'll be talking about how pathogens have exerted
a strong selective pressure throughout
human history and how humans have genetically adapted to it.
0:17
Genetic adaptation to new environments has hold an important role during human evolution.
In addition human migration to colder climates and with less incident of sunlight,
had adapted consequences for pigmentation or metabolic traits,
likewise the changes in the subsistence strategies,
for instance, after the advent of agriculture,
a lot for both the establishment of larger and connected social groups,
and for the availability of novel sources of food,
with a notable impact at the metabolism level.
Finally, the population expansions and proximity to livestock,
as well as recent human migrations and colonization of new habitats,
enhanced the exposures to novel infective agents and the spread of new diseases,
imposing a strong selective pressure at the immune system level.
These observations raised the question of to what extents
these selective pressures have left a signature in the human genome.
1:11
Genome-wide scans for signatures of natural selection in
the human genome aimed at identifying
regions showing unusual patterns of allele frequency,
haplotype diversity, or allelic differentiation between populations.
Here in this table, I think coworkers collected some of
the well-established examples of genes targeted by natural selection.
Functionality has been somehow validated by in vitro or in vivo experiments.
A decreased in melanin pigmentation in Europeans and a decrease in hemoglobin concentration
in Tibetans and Ethiopians probably reflect
genetic adaptation to certain environmental conditions,
namely, the exposure to reduced UV radiations,
and the hypoxia to high altitude.
This persistence is one of the most notable examples of genetic adaptation to diet,
with the polymorphism promoting the expression of the gene,
encoding the enzyme lactase being at high frequency in European populations,
and almost absent as well.
Nevertheless, many biological pathways involved in the regulation of the immune system,
and especially in modulation of a susceptibility to infectious disease,
are enriched with signals of neo-neutral evolution,
reflecting genetic adaptation to pathogen exposure.
Indeed, several studies have confirmed the hypothesis whereby virtuous agents have
exerted an exceptionally strong selective pressure on human population,
and shaped the genetic diversity of melanocyte in the human genome.