Island biogeography theory explains how contrasting combinations of area and distance can potentially result in similar equilibrium richness through different mechanisms. The close small island benefits from high immigration due to proximity but suffers high extinction due to limited area and small populations. The far large island experiences low immigration due to distance but enjoys low extinction due to ample area supporting large, stable populations. When these trade-offs balance appropriately - high immigration offsetting high extinction, and low extinction compensating for low immigration - both islands can achieve similar equilibrium richness despite their very different characteristics.

Island biogeography theory indicates that maximizing equilibrium species richness requires both increasing immigration (through better connectivity) and decreasing extinction (through larger area). Increasing island area provides more habitat space, allowing larger populations and more diverse habitats, which reduces extinction rates. Improving connectivity to the mainland increases immigration rates by making colonization easier and more frequent. This dual approach addresses both sides of the species equilibrium equation - more species arrive and fewer are lost to extinction - resulting in the highest possible species richness for conservation purposes.

Island biogeography theory predicts that immigration rate increases as distance to the mainland decreases. Reserve 2, being only 5 km offshore compared to Reserve 1's 40 km distance, will receive more colonizing species because dispersing organisms have a much higher probability of successfully reaching the closer island. Since both reserves have identical area (120 km²), they will have similar extinction rates, but Reserve 2's dramatically higher immigration rate will result in a higher equilibrium species richness. The closer distance facilitates more frequent colonization events, maintaining higher species diversity over time.

Island biogeography theory shows that equilibrium species richness increases when immigration rates increase and/or extinction rates decrease. Building a causeway would effectively reduce the island's isolation by providing a direct connection to the mainland, dramatically increasing immigration rates as species can now walk, fly, or disperse more easily to the island. This enhanced connectivity would shift the immigration curve upward while likely keeping extinction rates similar, resulting in a new equilibrium at higher species richness. The other options would either decrease immigration (increasing distance) or increase extinction (reducing area or habitat diversity).

Island biogeography theory predicts that connecting an island to the mainland via land bridge dramatically increases immigration rates by eliminating water barriers to dispersal. During the land-bridge period, the small island would function more like a peninsula than an isolated island, allowing easy movement of species to and from the mainland. This connection would result in much higher immigration rates and likely higher equilibrium species richness compared to the isolated period. The island would essentially have access to the full mainland species pool rather than being limited by over-water dispersal capabilities.

The species-area relationship $S=cA^z$ shows that species richness increases with island area when the exponent z is positive. Since Island 2 has an area of 100 km² compared to Island 1's 25 km², and z>0, the model predicts Island 2 will support more species. This relationship exists because larger islands can support larger populations (reducing extinction risk), contain more diverse habitats and microenvironments, and provide more ecological niches for species to exploit. The constant c represents the baseline richness, but the area effect $(A^z$) means larger islands consistently support more species than smaller ones with similar environmental conditions.

Island biogeography theory attributes higher species richness on closer islands primarily to increased immigration rates. Islands nearer to the mainland receive more colonizing species because dispersing organisms face shorter distances and higher success rates in reaching their destination. The shorter distance reduces the probability of mortality, disorientation, or exhaustion during dispersal, resulting in more successful colonization events. This higher immigration rate, combined with similar extinction rates (assuming equal areas), leads to higher equilibrium species richness on closer islands through more frequent replenishment of the species pool.

Island biogeography theory predicts that a large, near island will experience both high immigration (due to proximity to the mainland) and low extinction (due to large area supporting stable populations and diverse habitats). The combination of being close to the species source and having ample area creates optimal conditions for maintaining high species richness. High immigration ensures regular arrival of new colonists, while low extinction means established species persist longer. This combination results in the highest possible equilibrium species richness according to the theory, making large, near islands biodiversity hotspots.

Island biogeography theory explains that closer islands receive more immigrants due to higher colonization success rates, leading to higher species richness. Island A (near) having 75 species compared to Island B (far) having 45 species, despite identical size, demonstrates the distance effect on immigration. The proximity of Island A to the mainland increases the probability that dispersing organisms will successfully colonize it, resulting in higher immigration rates and consequently higher equilibrium species richness. This pattern supports the fundamental prediction that species richness decreases with increasing isolation from source populations.

According to island biogeography theory, when two islands have identical areas, their extinction rates are similar because area determines resource availability and population sizes. However, distance from the mainland dramatically affects immigration rates - closer islands receive more colonizers. Island Near (5 km away) will have much higher immigration rates than Island Far (200 km away) because dispersing organisms are more likely to successfully reach nearby islands. Since equilibrium species richness occurs where immigration equals extinction, and Island Near has higher immigration with similar extinction, its equilibrium point will be at a higher species richness. The greater influx of new species compensates for extinctions, maintaining higher diversity.