遗传控制鸟类迁徙路径 By tracking hybrids between songbird species, investigators have found that migration routes are under genetic control and could be preventing interbreeding. The research, which is published in Ecology Letters, was conducted using geolocators that, like GPS, record the position of a bird and allow its long distance movement to be tracked. Compared with their parents, hybrids exhibited increased variability in their migratory routes: some used intermediate routes across less suitable areas, while others used the same routes as one parental group on fall migration and the other on spring migration. This is the first time we ve been able to track songbirds over the entire annual cycle, and the data we collected support a longstanding hypothesis in ecological speciation, that differences in migratory behavior could be acting as postmating reproductive isolating barriers, said lead author Kira Delmore.
2017高考英语三轮复习完形填空专项训练29
2017高考英语三轮复习完形填空专项训练4
2017高考英语三轮冲刺阅读强化训练12
2017高考英语三轮冲刺阅读强化训练15
2017高考英语三轮冲刺阅读强化训练17
2017高考英语三轮冲刺阅读强化训练14
2017高考英语三轮复习完形填空专项训练30
2017高考英语三轮复习完形填空专项训练8
2017高考英语三轮复习完形填空专项训练26
2017高考英语三轮复习完形填空专项训练25
2017高考英语三轮复习完形填空专项训练22
2017高考英语三轮复习完形填空专项训练12
2017高考英语三轮冲刺阅读强化训练13
2017高考英语三轮复习完形填空专项训练23
2017高考英语三轮复习完形填空专项训练14
2017高考英语三轮冲刺阅读强化训练9
2017高考英语三轮冲刺阅读强化训练16
2017高考英语三轮复习完形填空专项训练16
2017高考英语三轮复习完形填空专项训练21
2017高考英语三轮复习完形填空专项训练5
2017高考英语三轮冲刺阅读强化训练18
2017高考英语三轮复习完形填空专项训练9
2017高考英语三轮复习完形填空专项训练24
2017高考英语三轮复习完形填空专项训练28
2017高考英语三轮冲刺阅读强化训练11
2017高考英语三轮冲刺阅读强化训练1
2017高考英语三轮冲刺阅读强化训练6
2017高考英语三轮冲刺阅读强化训练4
2017高考英语三轮冲刺阅读强化训练8
2017高考英语三轮复习完形填空专项训练10
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |