Several vertebrate species can distinguish between, say, two and five bananas —______（填一句話(huà)，本句開(kāi)頭不大寫(xiě)。）________
Now, new research suggests that pigeons, like primates, can follow these abstract numerical rules. The study is in the journal Science.
Researchers trained pigeons with cards on which were pictures of one, two or three shapes, sometimes in different sizes and colors. The birds were ultimately able to correctly pick a card with one large green square first, followed by a card with two small red ovals, followed by one showing three long blue rods.
Then, the pigeons demonstrated a new ability — faced with two cards each showing up to nine images, they could tell which card had more. Which indicates that they had an abstract understanding of the single-digit amounts. Rhesus monkeys trained in a similar way displayed the same talents. Whether this shared ability evolved independently or came from a common ancestor is unclear. But it is clear that birdbrains aren’t so dumb.
but with the exception of primates, they can't grasp the numerical rules that would let them arrange the piles of fruit from least to most.
with the exception of adv. 除…以外 numerical adj. 數(shù)字的, 用數(shù)字表示的, 數(shù)值的 一些脊椎物種有能力把2根香蕉和5根香蕉區(qū)分開(kāi)。但是除靈長(zhǎng)類(lèi)動(dòng)物之外，它們無(wú)法掌握把水果從少放到多的數(shù)字規(guī)則。現(xiàn)在，新的研究表明像靈長(zhǎng)類(lèi)動(dòng)物一樣，鴿子能掌握這些抽象的數(shù)字規(guī)則。這項(xiàng)研究發(fā)表于期刊“科學(xué)”上。 研究人員用一些印有數(shù)字的卡片來(lái)訓(xùn)練這些鴿子，卡片上是表示1、2、3含義的形狀，有時(shí)這些形狀的大小、顏色會(huì)有些不同。這些鴿子最終能夠正確地進(jìn)行排序。首先，它們選出一張印有一個(gè)綠色大方塊的卡片。然后，選出一張有兩個(gè)紅色小橢圓的卡片。最后，選出有三個(gè)藍(lán)色長(zhǎng)棒的卡片。 然后，鴿子們還展示出了新的技能，當(dāng)面對(duì)每張都有多達(dá)九種圖形的兩張卡片時(shí)，它們能區(qū)分出哪種卡片上的數(shù)字加起來(lái)之后更大。這一技能表明，它們能理解個(gè)位數(shù)的抽象含義。用同樣方法訓(xùn)練的獼猴也能習(xí)得相同的技能。目前尚無(wú)定論這一相同的能力是兩個(gè)物種獨(dú)立進(jìn)化的結(jié)果還是起源于同一祖先。但有一點(diǎn)是肯定的，那就是“傻”鳥(niǎo)不傻。