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  • 动物行为演变

    A group of elephants near water, one spraying water from its trunk.

    What is this elephant doing?
    ::这大象在干什么?

    Obviously he is spraying from his trunk. Why? Is this elephant’s behavior a form of playing or is there another possible reason?
    ::很明显,他正在从后备箱喷洒喷雾。 为什么?这只大象的行为是玩耍的一种形式,还是还有其他可能的原因?

    Animal Behavior
    ::动物行为行为

    Did you ever see a dog sit on command? Have you ever watched a cat trying to catch a mouse? These are just two examples of the many behaviors of . includes all the ways that animals interact with each other and the environment. Examples of common animal behaviors are pictured in Figure .
    ::你见过一只狗听命行事吗?你有没有看过一只猫想抓老鼠?这些只是许多动物行为的两个例子。它们包括动物相互作用和环境的所有方式。图中描绘了常见动物行为的例子。

    Animals interacting: sheep herding, pig nursing, and child observing nature.

    Examples of Animal Behavior. Can you think of other examples of animal behavior besides the three shown here?
    ::动物行为的例子。 除了这里显示的三种动物行为之外, 你能想到其它动物行为的例子吗 ?

    The branch of biology that studies animal behavior is called ethology . Ethologists usually study how animals behave in their natural environment, rather than in a lab. They generally try to answer four basic questions about the behaviors they observe:
    ::研究动物行为的生物学分支被称为“神学 ” 。 伦理学家通常研究动物在自然环境中的行为方式,而不是在实验室中的行为方式。 他们通常试图回答关于他们所观察到的行为的四个基本问题:

    1. What causes the behavior? What is the stimulus , or trigger, for the behavior? What structures and functions of the animal are involved in the behavior?
      ::是什么原因导致行为?什么刺激,或触发因素是什么?动物的行为涉及什么结构和功能?
    2. How does the behavior develop? Is it present early in life? Or does it appear only as the animal matures? Are certain experiences needed for the behavior to develop?
      ::行为如何发展? 行为是在生命的早期出现吗? 还是只是动物成熟时出现? 行为是否需要某些经验才能发展?
    3. Why did the behavior evolve? How does the behavior affect the fitness of the animal performing it? How does it affect the survival of the ?
      ::为什么行为会演变?行为会如何影响动物的适应性?它会如何影响动物的生存?
    4. How did the behavior evolve? How does it compare with similar behaviors in related species? In what ancestor did the behavior first appear?
      ::行为是如何演变的?它如何与相关物种的类似行为相比较?行为最初出现在哪个祖先身上?

    Evolution of Animal Behavior
    ::动物行为演变

    To the extent that behaviors are controlled by genes , they may evolve through . If behaviors increase fitness , they are likely to become more common over time. If they decrease fitness, they are likely to become less common.
    ::当行为受基因控制时,它们可能会演变。如果行为提高健康度,它们可能会随着时间的流逝而变得更为常见。如果行为降低健康度,它们就可能变得不那么常见。

    Nature vs. Nurture
    ::自然与创造

    Some behaviors seem to be controlled solely by genes. Others appear to be due to experiences in a given environment. Whether behaviors are controlled mainly by genes or by the environment is often a matter of debate. This is called the nature-nurture debate . Nature refers to the genes an animal inherits. Nurture refers to the environment that the animal experiences.
    ::有些行为似乎完全由基因控制。 另一些行为似乎是由于特定环境中的经历造成的。 行为主要受基因控制还是受环境控制往往是争论的问题。 这被称为自然神经辩论。 自然是指动物继承的基因。 发明是指动物经历的环境。

    In reality, most animal behaviors are not controlled by nature or nurture alone. Instead, they are influenced by both nature and nurture. In dogs, for example, the tendency to behave toward other dogs in a certain way is probably controlled by genes. However, the normal behaviors can’t develop in an environment that lacks other dogs. A puppy raised in isolation from other dogs may never develop the normal behaviors. It may always fear other dogs or act aggressively toward them.
    ::在现实中,大多数动物行为不是受自然控制,也不是只受培养。 相反,它们受自然和培养的影响。 比如,在狗身上,以某种方式对待其他狗的倾向可能受基因控制。 然而,正常行为不可能在缺少其他狗的环境中发展。 被孤立于其他狗的狗永远无法发展正常行为。 它可能总是害怕其他狗或对他们采取激进行动。

    How Behaviors Evolve
    ::行为如何演化

    It’s easy to see how many common types of behavior evolve. That’s because they obviously increase the fitness of the animal performing them. For example, when wolves hunt together in a pack, they are more likely to catch prey (see Figure ). Therefore, hunting with others increases a wolf’s fitness. The wolf is more likely to survive and pass its genes to the next generation by behaving this way.
    ::很容易看出有多少常见的行为类型会演变。 这是因为它们显然提高了动物进行这种行为的适合性。 比如,当狼群一起捕猎时,它们更有可能捕食猎物(见图 ) 。 因此,与其他人一起捕猎会增加狼体的体质。 狼更有可能生存下来,并通过这种做法将其基因传给下一代。

    Wolves hunting a bison in the snow, demonstrating cooperative hunting behavior.

    Wolves hunt together in packs. This is adaptive because it increases their chances of killing prey and obtaining food.
    ::狼群聚在一起捕食,这是适应性的,因为它增加了猎物和食物的捕食机会。

    The evolution of certain other types of behavior is not as easy to explain. An example is a squirrel chattering loudly to warn other squirrels that a predator is near. This is likely to help the other squirrels avoid the predator. Therefore, it could increase their fitness. But what about the squirrel raises the alarm? This squirrel is more likely to be noticed by the predator. Therefore, the behavior may actually lower this squirrel’s fitness. How could such a behavior evolve through natural selection?
    ::某些其他类型行为的演进并不容易解释。 例如松鼠大声叫喊警告其他松鼠捕食者已经接近。 这可能帮助其他松鼠避免捕食者。 因此,它可以提高它们的健康性。 但是松鼠会提高警报力吗?捕食者更可能注意到松鼠。 因此,该行为实际上可能会降低松鼠的健康状况。 这种行为如何通过自然选择演化?

    One possible answer is that helping others often means helping close relatives. Close relatives share many of the same genes that they inherited from their common ancestor. As a result, helping a close relative may actually increase the chances that copies of one’s own genes will be passed to the next generation. In this way, a behavior that puts oneself at risk could actually increase through natural selection. This form of natural selection is called kin selection .
    ::一种可能的答案是帮助他人往往意味着帮助近亲。 近亲分享着他们从共同祖先继承的许多相同基因。 结果,帮助近亲可能实际上增加自己基因副本传给下一代的可能性。 这样,让自己面临风险的行为可以通过自然选择而增加。 这种自然选择形式被称为亲属选择。

       

     

    Science Friday: When Eels Attack!
    ::当埃尔斯攻击时!

    Electric eels have been known to jump out of the water and shock animals like horses. What would cause this extraordinary behavior? In this video by Science Friday, Kenneth Catania of Vanderbilt University discusses this behavior and the that demonstrate this.
    ::电els是众所周知的跳出水面,像马一样震撼动物。什么会引发这种非同寻常的行为?在这段由科学周五拍摄的视频中,范德比尔特大学的肯尼斯·卡塔尼亚(Kenneth Catania)讨论了这一行为以及证明这一点的。

     

    Science Friday: Run, Octopus, Run!
    ::快跑,章鱼,快跑!

    Octopus move around using a variety of motions. One unique motion they can perform is to “run” backwards on two arms. In this video by Science Friday, Chrissy Huffard at Stanford explains the possible use of this behavior
    ::奥克塔普斯使用各种动作来移动。他们可以执行的一个独特的动作就是“向”两臂“向后跑 ” 。 在科学周五的这段影片中,斯坦福的克里斯西·赫法德解释了这种行为的可能用途。

     

     

    Summary
    ::摘要

    • Most animal behaviors are controlled by both genes and experiences in a given environment.
      ::大多数动物行为都受基因和特定环境中的经验控制。
    • To the extent that behaviors are controlled by genes, they may evolve.
      ::只要行为受基因控制,它们就可能演变。
    • Behaviors that improve fitness increase through natural selection.
      ::通过自然选择提高体能的行为。

    Review
    ::回顾

    1. Define animal behavior.
      ::给动物行为下定义
    2. What is the nature-nurture debate?
      ::自然神经辩论是什么?
    3. What is kin selection?
      ::什么是亲属选择?
    4. How do behaviors become common?
      ::行为如何变得司空见惯?