Genetic Drift and Human Evolution

These flashcards summarize key concepts related to genetic drift, human evolution, bottlenecks, and the FitCoal method from the lecture notes.

What are 'bottlenecks' and 'founder effect' considered in genetic terms?

Both are examples of genetic drift, which involves changes in allele frequencies due to chance events.

How does genetic drift affect DNA polymorphisms?

Genetic drift can lead to the loss of genetic variation within a population, affecting the frequency of DNA polymorphisms.

What is the role of mutation in DNA polymorphisms?

Mutation introduces new alleles into a population, increasing genetic diversity and contributing to DNA polymorphisms.

Define 'Effective Population Size' in your own words.

Effective Population Size is the number of breeding individuals that contribute to the gene pool of the next generation, reflecting the genetic diversity of a population.

What was the estimated population size during the human bottleneck in the Early to Middle Pleistocene?

About 1280 breeding individuals.

How long did the human bottleneck last during the Pleistocene?

Approximately 117,000 years.

What does FitCoal do in the context of demographic inference?

FitCoal fits the expected site frequency spectrum of a demographic model to the observed SFS to infer population size histories and demographic events.

What is the Site Frequency Spectrum (SFS)?

The SFS summarizes the distribution of allele frequencies across a genome, aiding in the understanding of genetic variation.

How does FitCoal detect a population bottleneck?

By comparing the expected SFS of a constant population size model to the observed SFS and identifying significant deviations.

What time period does the Early to Middle Pleistocene transition refer to in human history?

Between approximately 1250 to 700 thousand years ago.

What major event coincided with the human bottleneck according to the study?

The bottleneck corresponds with a substantial chronological gap in the fossil record of African and Eurasian populations.