Why is Sexual Reproduction Common?

Introduction

Sexual reproduction is prevalent among many species despite some reproducing asexually.
99% of plants, animals, fungi, and protists reproduce sexually at least some of the time.
Some species like starfish, slugs, and strawberries can switch between sexual and asexual reproduction.

Sexual Reproduction: Involves two organisms combining genetic material to create genetically diverse offspring.
- Examples: Humans, pandas, grasshoppers.
Asexual Reproduction: One organism reproduces without genetic mixing, creating genetic clones.
- Methods:
  - Binary Fission: Organism splits in half (e.g., bacteria, protists).
  - Budding: Organisms like hydras produce "buds" that grow into new organisms.
  - Vegetative Reproduction: Through bulbs, tubers, or rhizomes.
  - Parthenogenesis: "Virgin birth" seen in New Mexican Whiptail lizards.
  - Fragmentation: Parent organism breaks into pieces, each developing into a new organism.

Genetic Variation: Increases the population's adaptability to changes and resistance to diseases.
Red Queen's Hypothesis: Constant adaptation is necessary to survive against predators and competitors.
- Sexually reproducing organisms (e.g., snails, worms) resist infestations better than asexual ones.
Genetic Mutations: Asexual populations accumulate bad mutations, potentially wiping them out over generations.

While asexual reproduction is efficient, sexual reproduction provides key genetic diversity benefits.
Sexual reproduction helps populations sustain through varying conditions and threats.
Many asexual organisms keep the option of sexual reproduction for adverse conditions.

Note: For more detailed information, refer to scientific studies and resources cited in educational materials.

Safe sexual practices are encouraged for humans (e.g., use of condoms or birth control).