And a back - of - the - envelope calculation based on the 1 . 8m sorts of organism recognised so far as species under the linnaean system , on the rate at which new species are being discovered and on such ecological matters as the average number of parasites ( themselves new species ) that each free - living species harbours , suggests the final total may be around 30m 一个以三部分，即：在林耐分类系统中迄今为止被认定是物种的180万种微生物、新物种的发现速率和诸如在每个独立生存的物种中藏匿的平均寄生虫数量（它们本身也属于新物种）等生态因素，为基础的估算表明全球物种的总数是在三百万左右。
