Related Experiment Video
Updated: Mar 1, 2026

08:03
Methods for Staging Pupal Periods and Measurement of Wing Pigmentation of Drosophila guttifera
Published on: January 24, 2018
12.4K
EVOLUTIONARY HISTORY OF DROSOPHILA BUZZATII. II. HOW MUCH HAS CHROMOSOMAL POLYMORPHISM CHANGED IN COLONIZATION?
A Fontdevila1, A Ruiz1, J Ocaña2
1Departamento de Genética, Facultad de Biología, Universidad de Santiago de Compostela, Spain.
Summary
No abstract available in PubMed .
Related Concept Videos
Position-effect Variegation
7.2K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.2K
Polytene Chromosomes
11.2K
Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also...
11.2K
Mutation, Gene Flow, and Genetic Drift
65.0K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
65.0K
Exon Recombination
4.2K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
4.2K
Speciation Rates
23.1K
Overview
23.1K
Genetics of Speciation
22.5K
Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.
22.5K

