Species tend to live in narrower slices of mountainside on tropical versus temperate mountains. Stronger competition in the tropics explains this pattern for birds. For example, the habitable range of this white-tipped sicklebill (Eutoxeres aquila) is limited as a result of competition with its close relative, the buff-tailed sicklebill (Eutoxeres condamini). See page 416.
Fast-spreading subvariants are coming and going. But an entirely new variant could still emerge
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Finding sequences that code for short proteins could add thousands of genes