APES Unit 2 Key Terms

Ever wonder why some animals can live practically anywhere while others disappear when their habitat changes slightly? This is where specialists and generalists come in. Specialists need specific conditions to survive, while generalists can thrive in various environments.

When populations shrink dramatically, they experience a genetic bottleneck, which reduces genetic diversity and makes species more vulnerable to extinction. This concept connects to biodiversity, which we measure through species richness (the number of different species in an area) and species evenness (how individuals are distributed among species).

Evolution refers to changes in genetic composition of populations over time. It occurs at different scales: microevolution happens below the species level, while macroevolution creates new species or higher classifications. These processes involve genes (physical locations on chromosomes), which collectively form an individual's genotype. The observable traits that result are called the phenotype.

💡 Quick Insight: A trophic cascade demonstrates ecosystem interconnectedness - when one level in a food web is disrupted (like removing predators), it triggers dramatic changes throughout the entire system.

Changes in genetic material occur through mutations (random changes in genetic code) and recombination (when chromosomes exchange genetic material during reproduction). These mechanisms drive the diversity we see in nature!