Were the Tertiary radiations of the Australian flora synchronous? A molecular phylogenetic approach

化石记录表明，在大约20万年的短时期内，古老的冈瓦纳雨林让位于独特的澳大利亚？硬叶？植物群以桉树、阿卡西亚斯和刺槐为主。 这与干燥的气候和火灾的出现相吻合。 据推测，？爆炸性？进化辐射迅速增加了硬叶植物物种的数量，而不仅仅是原有物种的范围扩大。 在一种新的方法中，几个远亲植物群体的分子遗传学将被用来测试爆炸性进化辐射是否同时发生，并确定环境触发因素。

The fossil record shows that in a short period from about 20 Mya, the ancestral Gondwanan rainforest gave way to the unique Australian ?sclerophyll? flora dominated by eucalypts, acacias and casuarinas. This coincided with a drying climate and the advent of fire. It is hypothesized that ?explosive? evolutionary radiations rapidly increased the number of sclerophyll species, rather than a mere range expansion of pre-existing species. In a novel approach, molecular phylogenies of several distantly related plant groups will be used to test whether explosive evolutionary radiations took place simultaneously and to identify the environmental triggers.