关于南方汉人的蒙古人基因占比大的可能猜想

{"result":[{"race_desc":"\u4e2d\u534e\u6c11\u65cf","race_en":"chinese_nation","race_probality":"0.984836","area":[{"block":"chinese_nation","race_desc":"\u5357\u65b9\u6c49\u65cf","race_en":"han_southern","race_probality":"0.417906"},{"block":"chinese_nation","race_desc":"\u8499\u53e4\u8bed\u65cf\u7fa4","race_en":"mongolian","race_probality":"0.261233"},{"block":"chinese_nation","race_desc":"\u5317\u65b9\u6c49\u65cf","race_en":"han_northern","race_probality":"0.250301"},{"block":"chinese_nation","race_desc":"\u9ad8\u5c71\u65cf","race_en":"gaoshan","race_probality":"0.024380"},{"block":"chinese_nation","race_desc":"\u82d7\u7476\u8bed\u65cf\u7fa4","race_en":"miao_yao","race_probality":"0.012588"},{"block":"chinese_nation","race_desc":"\u7eb3\u897f\/\u5f5d\u65cf","race_en":"ny","race_probality":"0.010749"},{"block":"chinese_nation","race_desc":"\u62c9\u795c\u65cf","race_en":"lahu","race_probality":"0.007629"},{"block":"chinese_nation","race_desc":"\u5176\u4ed6","race_en":"other","race_probality":"0.0003"}]},{"race_desc":"\u4e1c\u5317\u4e9a","race_en":"ne_asian","race_probality":"0.014894","area":[{"block":"ne_asian","race_desc":"\u97e9\u56fd","race_en":"korean","race_probality":"0.014874"}]},{"race_desc":"\u5176\u4ed6","race_en":"other","race_probality":"0.0004","area":[]}],"case_id":"ANCESTRY","prefix":null,"description":"\u7956\u6e90\u5206\u6790","color":null,"detail_url":"\/report2\/ancestry\/"} 我是湖北人，这里是唯一一个会弹舌的汉族人居住地。说法一：这里保留了古楚语的颤音。说法二：这里在元朝时期被蒙古贵族统治，保留了部分蒙古语的发音，颤音就是其中保留最完整的。
我比较赞同第二种说法，毕竟基因不会说谎。