1. Both are part of the Earth's surface: Highlands and lowlands are both natural geographical features that make up the landforms of the Earth. They differ in elevation, but they are both integral parts of the planet's topography.
2. Both can support life: While highlands and lowlands have different climates and ecosystems, both are capable of supporting various forms of life. Highlands might have alpine vegetation and animals adapted to cold, thin air, while lowlands could support forests, grasslands, or even deserts depending on their location and climate.