"survival of the fittest" meaning in All languages combined

{
  "categories": [
    {
      "kind": "other",
      "name": "Английский язык",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Требуется категоризация/en",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Устойчивые сочетания/en",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Английский",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Биологические термины/en",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "естественный отбор"
      ],
      "id": "ru-survival_of_the_fittest-en-phrase-1f4ggl7c",
      "topics": [
        "biology"
      ]
    }
  ],
  "word": "survival of the fittest"
}

{
  "categories": [
    "Английский язык",
    "Требуется категоризация/en",
    "Устойчивые сочетания/en"
  ],
  "lang": "Английский",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "categories": [
        "Биологические термины/en"
      ],
      "glosses": [
        "естественный отбор"
      ],
      "topics": [
        "biology"
      ]
    }
  ],
  "word": "survival of the fittest"
}