Asexual reproduction
Asexual Reproduction
Works best in stable, predictable environments where the parent genotype is already successful.
Can quickly colonize new or empty habitats.
Long-term disadvantage: accumulation of harmful mutations .
Sexual Reproduction
Generates genetic variation through mixing DNA → offspring can survive new stresses or diseases.
Facilitates adaptation to parasites and environmental change (Red Queen hypothesis).
Sometimes used seasonally to produce dormant or stress-resistant stages).
Facultative Switching (Asexual ↔ Sexual)
Organisms may switch to sexual reproduction when:
Population density increases → competition rises.
Environmental stress occurs → variation needed.
Parasite pressure increases → offspring diversity improves survival.
Asexual reproduction is favored for rapid expansion, sexual reproduction for long-term survival.
Cloning in Biotechnology
Mimics natural asexual reproduction (vegetative propagation) but uses somatic cell nuclear transfer.
Risks include reduced genetic diversity, amplified mutations, and ecological consequences if clones escape into the wild.
Raises ethical concerns about animal welfare and human cloning.
Rapid Spread Implications
Invasive species: a single individual can establish a population because asexual reproduction produces many copies quickly.
Bacteria & antibiotic resistance: mutations or resistance genes can spread fast through cloning - public health risk.