BIOL 300C Evolution Lecture 12 Microevolution

A set of flashcards covering key concepts from the lecture on microevolution, including definitions of terms, concepts of genetic diversity, and implications of inbreeding.

What is the 'Habsburg jaw'?

A deformity common to the Habsburg dynasty of 15th-17th century Europe.

What are model organisms?

Model organisms are species that are extensively studied to understand biological processes, including E. coli, yeast, Drosophila, C. elegans, Arabidopsis, and mice.

What is the effective population size (Ne)?

Effective Population Size (Ne) is the size of an idealized population that would experience the same rate of genetic drift as the real population.

How does inbreeding impact deleterious alleles?

Inbreeding increases the probability that deleterious recessives will be homozygous in an individual.

What is inbreeding depression?

Inbreeding depression is a decline in fitness due to the expression of deleterious recessive alleles.

What is genetic purging?

Genetic purging is the process where selection against deleterious recessives strengthens in a chronically inbred population, leading to the removal of these alleles over time.

What was the estimated Ne for the current Cheetah population?

The estimated Ne for the current Cheetah population is 15.4.

What is mutation-selection balance?

Mutation-selection balance occurs when the rate of introduction of deleterious recessive alleles by mutation equals the rate of elimination by selection.

What are the advantages of genetic rescue?

1. Increased genetic diversity 2. Decreased probability of identity-by-descent (IBD) and resulting inbreeding depression.

What are the risks of genetic rescue?

1. Potential replenishment of harmful recessive alleles reduces mean fitness. 2. Translocating individuals erases the distinctiveness of local populations.

What phenomena occurs when copies of the same chromosomal segments are inherited from a shared ancestor?

This is called identity-by-descent (IBD).

Why are genomes not riddled with deleterious mutations?

Purifying selection acts to eliminate deleterious mutations, and the stronger the deleterious effect of an allele, the stronger the selection pressure against it.

What was a finding from the 2017 study comparing ancient and modern mammoths?

The genomes of surviving Wrangel Island mammoths exhibited high rates of deletions, retrogenes, and non-functionalizing mutations.

Why is the study of emerging model organisms important?

Emerging model organisms can better address scientific questions than traditional models, especially with advances in sequencing and functional genomics.

What is identity-by-descent (IBD) in terms of inbreeding?

Inbreeding results in IBD when segments of chromosomes inherited from shared ancestors come together in an individual.