introduction：
1.Olfactory receptors (ORs)很重要
2.已知的ORs的分子结构，但仍存在没清楚的地方：
Though the relationship between odors and ORs is not clear, it has been hypothesized that a combinatorial coding scheme might allow a single OR to identify multiple odors and also permit different ORs to identify similar odors
transmembrane protein：
is a type of integral membrane protein that spans the entirety of the cell membrane to which it is permanently attached. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane.
所以我们通过分析ORs基因，找到它与oders的相互作用。
3. OR genes在脊椎动物中的保守序列最多（易于研究）
4.
这是47个物种的OR gene个数及其测序深度：
其坐标来自：
3.关于ORs gene family classify：
1.因为红框gene只有fish and fishes and amphibians 有
2. a and g OR genes ：tetrapod specific(bar one g gene in the zebrafish).
3.b group is reported in both tetrapods and fishes
基于我们研究的（48 birds and 2 reptiles）筛选后得到（研究对象）：
5.生物学适应加速了嗅觉受体的进化
6.研究内容：In this study, we characterized the OR gene family repertoire of 48 avian and 2 reptilian genomes to assess how ecological conditions may have shaped patterns of diversification of olfactory abilities and to assess correlations among genetic patterns and olfactory ability, behavior and morphology including olfactory bulb size, feeding and activity habits, and patterns of cognitive ability such as vocal learning in birds.