An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Biotic factors include plants, animals, and other organisms. Abiotic factors are non-living and include rocks, temperature, and humidity.
Darwin could compare only the anatomy and embryos of living things. Today, scientists can compare their DNA. Similar DNA sequences are the strongest evidence for evolution from a common ancestor.
