91Ó°ÊÓ

Genetic vulnerability refers to the challenges faced by small populations due to limited genetic diversity. When a population is small, it undergoes inbreeding, where close relatives breed with each other due to lack of options. This results in a lower genetic variation, akin to having all your eggs in one basket. Without enough diversity, these populations struggle to adapt to new changes or threats in their environment.
For example, a disease that targets a specific genetic trait may affect all individuals in the group because they share similar genetics. Moreover, low genetic diversity can lead to the accumulation of harmful genetic mutations over generations, which might weaken individuals' health and reduce their reproductive success.

• Lack of genetic diversity means low adaptability.
• Prone to diseases that target similar genes.
• Accumulation of harmful mutations.

In these ways, small populations are genetically vulnerable, increasing their risk of extinction.

Demographic fluctuations are variations in population due to changes in birth rates, death rates, and sex ratios. In large populations, these fluctuations tend to even out over time, but in small populations, they can have a disastrous impact. For instance, if birth rates drop just slightly or if there is a sudden increase in deaths, the population might not recover.
Similarly, an unequal sex ratio can hinder reproduction. If there are significantly more males than females, or vice versa, the number of breeding pairs is limited, making population recovery slower or even stagnate.

• Birth and death rates fluctuate more severely.
• Imbalanced sex ratios limit reproduction.
• Small numbers amplify minor demographic changes.

These demographic fluctuations make small populations unstable and increase their risk of going extinct.

Environmental stochasticity refers to random and unpredictable environmental changes that can affect populations. Examples include natural disasters like hurricanes, floods, droughts, or fires. Large populations have more individuals to absorb these impacts and are generally more resilient.
For small populations, however, such events can significantly reduce numbers or destroy habitats, from which they cannot easily recover. These random events do not discriminate between large and small populations, but their impact is devastating on smaller groups due to their lack of backup numbers.

• Vulnerability to natural disasters.
• Less capacity to recover from environmental changes.
• Random events lead to severe consequences in small numbers.

This susceptibility to environmental stochasticity poses a severe threat to the survival of small populations.