Genetic Diversity Flashcards

Study Notes

Genetic Diversity Overview

Genetic diversity refers to the variation of alleles within a species, crucial for adaptability and survival.
More closely-related species share more DNA, while distinct species exhibit significant genetic differences.

Characteristics of Genetic Diversity Within Species

Within a single species, DNA shows minimal variation, yet individual members can possess different alleles.
The variety in alleles contributes to the genetic diversity of a population, affecting evolution and adaptability.

Importance of Genetic Diversity

Critical for the survival of species; a greater number of alleles enhances adaptability to environmental changes.
Diverse alleles increase the likelihood that individuals will possess traits suitable for survival and reproduction under changing conditions.

Selective Breeding

Involves selecting individuals with desirable traits to parent future generations.
Offspring not exhibiting these traits are often culled, leading to reduced genetic variation.

Impact of Selective Breeding on Genetic Diversity

Selective breeding narrows the gene pool, reducing the variety and number of alleles within a population.
This practice can result in populations that possess desirable qualities but also demonstrate diminished genetic diversity.

Founder Effect

Occurs when a small group from a population migrates to a new area and establishes a new population.
The new population will inherit only a fraction of the original population's genetic variation.

Effects of Founder Effect on Genetic Diversity

Isolation of founding individuals can lead to a reduced gene pool with fewer alleles.
Fewer different alleles result in low genetic variation, potentially affecting the population’s ability to adapt.

Genetic Bottlenecks

Events such as natural disasters can significantly reduce population size, creating a genetic bottleneck.
These events lead to decreased genetic diversity as only a small number of individuals contribute to the gene pool.

Impact of Genetic Bottlenecks on Genetic Diversity

Surviving individuals possess a limited variety of alleles compared to the original population.
This results in a population with reduced genetic diversity and a narrower gene pool for future generations.

Case Study: Phenylketonuria

A mutation linked to phenylketonuria originated in Central Asia but has spread to various populations due to factors such as migration and interbreeding.

Selective Pressure on Sugar Beet

Selection processes can lead to reduced genetic diversity characterized by fewer distinct alleles and variations within the population.
Chosen alleles diminish overall genetic variation.

Common Genetic Disorders in Isolated Populations

Ellis-van Creveld syndrome is more prevalent in the Amish due to a small founding population and restricted interbreeding, leading to less genetic diversity.
Higher chances of allele inheritance are present in isolated communities compared to more genetically diverse populations.

Processes Leading to Reduced Genetic Diversity

Founder effect: Isolation of few individuals leads to smaller gene pools.
Genetic bottlenecks: Population size reduction due to random events limits genetic diversity.
Selective breeding: Focus on specific traits limits the variety of alleles, leading to less genetic variation overall.

Description

Explore key concepts in genetic diversity through these flashcards. Each card highlights important terms and definitions related to genetic variation within and between species. Perfect for students studying biology or genetics.