ide evidence that all four-limbed animals with backbones had descended with modifications from common ancestors.
             • Many embryos look similar during stages of early development.
             • Same groups of embryonic cells develop in the same order and in similar patterns to produce the tissues and organs.
             - Common cells and tissues growing in similar ways build, or lead up to, homologous structures as discussed before.
             • High birthrates and shortages of life basics needs would eventually force organisms into competition.
             • Members of each species compete regularly for food, living space, and other necessities of life.
             • Predators that are faster or have a particular method of ensnaring organisms will catch more prey. Prey that are faster, better camouflaged to the environment, or protected (pines on a porcupine) can avoid
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