14.5 动物行为演变 -- -- 先进
章节大纲
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Why would an do this?
::为什么要这么做?This baboon is showing altruistic behavior by removing parasites from another baboon's back. Is this behavior due to genes ? Is it an instinct ? Is it a ? Does it increase the fitness of the ? These are all good questions.
::这只浣熊把寄生虫从另一只浣熊的背上移走,从而表现出利他主义的行为。这是基因造成的吗?这是本能吗?是直觉吗?它能提高动物的体质吗?这些都是很好的问题。Evolution of Animal Behavior
::动物行为演变Many ethologists are interested in how affect fitness (the ability to survive and reproduce) and evolution. This interest in fitness and evolution is clearly seen in Tinbergen’s third and fourth questions. Evidence shows that many animal behaviors are at least partly controlled by genes. However, there are no genes that code directly for behavior. Genes code for (see the concepts), and a change in a single protein can cause wide-ranging effects throughout the body. It can dramatically influence an individual’s phenotype , or observable traits (see the Concept Inheritance (Advanced) chapter). On the other hand, the external environment also influences how most genes are expressed. Nonetheless, to the extent that behavior is controlled by genes, it may be subject to and evolution.
::许多神学学家对健康(生存和繁殖能力)和进化的影响很感兴趣。 这种对健康和进化的兴趣在Tinbergen的第三和第四个问题中都清楚可见。 证据表明许多动物行为至少部分受基因控制。 但是,没有基因直接为行为编码。 基因代码(见概念)和单一蛋白质的变化可以在整个身体中产生广泛的影响。 它可以极大地影响个人的性格或可观察到的特征(见概念继承(Advanced)一章 ) 。 另一方面,外部环境也影响着大多数基因的表达方式。 尽管如此,只要行为受基因控制,它可能受到基因的制约和进化。Nature vs. Nurture
::自然与创造As you read below about different examples of behavior, you will see that some behaviors seem to be mainly determined by genes, whereas others appear to be greatly influenced by experiences in a particular environment. Whether behaviors are controlled mainly by genes or by the environment is controversial. The controversy is often referred to as the nature-nurture debate . Nature refers to the genes that an individual inherits. Nurture refers to the environment in which the individual lives and the particular experiences the individual has throughout life.
::正如下文所阅读的不同行为例子,你会看到,有些行为似乎主要由基因决定,而另一些行为则似乎受到特定环境中经验的极大影响。行为是否主要受基因或环境控制是有争议的。争议通常被称为自然与神经辩论。自然是指个人继承的基因。创造是指个人生活的环境和个人在整个生命中的特殊经历。Some ethologists have used controlled to investigate the relative importance of genes and the environment in various animal behaviors. For example, they have raised baby animals in controlled environments without contact with other members of their . If a behavior still appears under these conditions, then it is assumed to be controlled almost completely by genes. Consider the example of a puppy raised by humans, without contact with other dogs. Like all normal dogs, the puppy will drool when it sees or smells food . It does not need to observe other dogs drooling in order to perform this behavior. It also does not need to be repeatedly exposed to food to develop the ability to drool.
::一些神学学家利用控制手段调查基因和环境在各种动物行为中的相对重要性。 例如,他们在没有与其他动物成员接触的情况下在受控制的环境中饲养幼崽动物。 如果在这些条件下仍然出现某种行为,那么就假定它几乎完全受基因控制。 想想人类饲养的小狗的例子,没有与其他狗接触。 和所有正常的狗一样,小狗在看到或闻到食物时会流口水。 它不需要观察其他流口水的狗来进行这种行为。 也不需要反复接触食物来发展流口水的能力。If a behavior does not appear in a controlled environment, this does not necessarily mean that the behavior has no genetic basis. It may mean only that the stimulus needed to trigger the behavior is not present. For example, a dog does not normally drool without the stimulus of food. However, drooling behavior is still known to be controlled by genes; that is, genes are involved in the production of saliva .
::如果一种行为没有出现在受控制的环境中,这并不一定意味着该行为没有遗传依据。 它可能仅仅意味着触发该行为的刺激没有出现。 比如,狗通常不会流口水,除非食物刺激。 但是流口水行为仍然由基因控制,也就是说,基因参与唾液生产。The same example shows how the environment can play a major role in shaping behavior. The puppy raised without contact with other dogs will not become socialized enough to interact normally with other members of its species. In fact, it is unlikely to ever interact normally with other dogs. It may always fear other dogs or act aggressively toward them. The tendency to behave toward other dogs in certain ways is probably controlled by genes. However, the behaviors cannot develop in an environment that deprives dogs of opportunities to interact.
::同一例子显示了环境如何在行为塑造中扮演主要角色。 没有与其他狗接触而长大的小狗不会被社会化到能够正常地与其他狗进行互动的程度。 事实上,它不可能正常地与其他狗进行互动。 它可能总是害怕其他狗或者对他们采取攻击行动。 以某种方式对待其他狗的倾向可能受到基因的控制。 但是,在剥夺狗互动机会的环境中,它们的行为无法发展。How Behaviors Evolve
::行为如何演化A behavior that is at least partly under genetic control can evolve through natural selection. However, being controlled by genes is not the only requirement for a behavior to evolve through natural selection. The individual performing the behavior also must have increased fitness due to the behavior. In other words, performing the behavior must increase the individual’s chances of surviving and successfully reproducing.
::至少部分受基因控制的行为可以通过自然选择而演变。 然而,受基因控制并不是通过自然选择而演变行为的唯一要求。 行为实施者还必须由于行为而提高身体健康。 换句话说,行为实施必须增加个人存活和成功再生的机会。Many behaviors make sense in terms of individual fitness and natural selection. For example, it is easy to see how “selfish” behaviors — such as successfully competing with other members of the same species for food and mates — could increase an individual’s fitness. By obtaining more food and mates, the individual has a greater chance of surviving and reproducing than less competitive members of the same species. Another example that is readily explained by natural selection is cooperative behavior, such as wolves hunting together as a pack. Hunting with the pack is more likely to be successful than hunting alone. Therefore, it could increase the fitness of all the animals in the pack.
::许多行为在个人健康和自然选择方面是有道理的。 比如,很容易看出“自私”行为 — — 比如与同一物种的其他成员成功竞争食物和伴侣 — — 能够提高个人的健康状况。 通过获得更多的食物和伴侣,个人比同种物种中竞争较少的成员更有可能生存和再生。自然选择中容易解释的另一个例子是合作行为,比如狼群一起打猎。与狼群打猎比单独打猎更可能成功。因此,它可以提高所有动物群的健康状况。Altruism, Sociobiology, and Kin Selection
::利他主义、社会生物学和 " 心心选择 "Other behaviors are harder to explain in terms of individual fitness and natural selection. Altruistic behavior is a prime example. Altruism means doing something for others that puts oneself at risk. Squirrels act altruistically when they make warning sounds to “tell” other squirrels that a predator is near. This is likely to help the other squirrels avoid the predator, which increases their fitness. However, the altruist is more likely to be noticed by the predator, which decreases the altruist’s fitness. If a behavior reduces the fitness of the individual performing it, how could the behavior persist in the species through natural selection?
::其他行为更难从个人健康和自然选择的角度来解释。利他主义行为是一个很好的例子。利他主义意味着为他人做一些危险的事情。利他主义意味着为他人做一些事情。 松鼠在发出警告声“警告”捕食者附近的其他松鼠时采取利他主义行为。 这很可能会帮助其他松鼠避免捕食者,因为这会增加他们的健康。 然而,利他主义更可能受到食肉动物的注意,从而降低利他主义者的健康状况。 如果某种行为会降低施食者的健康,那么如何通过自然选择在物种中持续?Altruistic behavior is the only type of behavior that Charles Darwin admitted he could not explain through natural selection. In his famous 1859 book, On the , Darwin referred to altruistic behavior as the “one special difficulty, which at first appeared to me insuperable, and actually fatal to my theory .”
::利他主义行为是查尔斯·达尔文承认他无法通过自然选择解释的唯一一种行为。 达尔文在他著名的1859年书《关于达尔文 》 ( On the, On the , Darvin) 中将利他主义行为称为“一个特殊困难 ” , 起初,在我看来,这是无法克服的,实际上对我理论来说是致命的 ” 。Sociobiologists have offered explanations for how altruism and similar behaviors evolve. Sociobiology is the study of how behavior increases fitness and evolves through natural selection. Sociobiologists assume that behaviors that persist or increase in frequency must be adaptive. They also assume that genes determine most behavioral traits. Many of the theories of sociobiology were developed by scientists studying the behavior of that live in social groups. The scientist that established sociobiology as a distinct scientific field, E.O. Wilson (see Figure ), was an expert on the of ants. Wilson tried to explain the behavior of other animals, including humans, based on his knowledge of .
::社会生物学家解释了利他主义和类似行为是如何演变的。社会生物学是研究行为如何通过自然选择提高健康水平和进化。社会生物学家认为,持续或增加频率的行为必须是适应性的。他们还假设基因决定着大多数行为特征。许多社会生物学理论是由研究生活在社会群体中的人的行为的科学家所开发的。将社会生物学确定为一个独特的科学领域的科学家E.O.Wilson(见图 ) , 是蚂蚁专家。威尔逊试图根据他对蚂蚁的知识来解释其他动物的行为,包括人类。E.O. Wilson founded sociobiology as a distinct field of study. He has received many honors and awards for his research and writing on the social behavior of ants. However, his explanations of human behavior have been criticized by many other scientists.
::E.O. Wilson建立了社会生物学,将其作为一个独特的研究领域。他因研究并撰写蚂蚁的社会行为而获得许多荣誉和奖赏。然而,他对人类行为的解释受到许多其他科学家的批评。One way in which Wilson and other sociobiologists have explained the evolution of altruism is through a process called kin selection . Kin selection refers to changes in gene frequencies from generation to generation that occur when biological relatives (kin) influence one another’s fitness. In ants and other insects that live in social groups, individuals in the group are close biological relatives. Therefore, an individual insect performing an altruistic behavior may be increasing the fitness of its kin. Close relatives share many of the same genes, which they have inherited from their common ancestor . As a result, helping out kin actually increases the chances that copies of genes found in the altruist will be passed on to the next generation. In this way, sociobiologists argue, genes that control altruism could be selected for and increase in frequency in a species.
::威尔逊和其他社会生物学家解释利他主义演变的方式之一是通过一个称为亲属选择的过程。 选择Kin指的是在生物亲属(亲属)影响他人身体健康时基因频率的代代相传的变化。 在生活在社会群体中的蚂蚁和其他昆虫中,该群体中的个人是近亲。 因此,实施利他主义行为的个体昆虫可能正在增加其亲属的健康状况。 近亲拥有许多相同的基因,他们从共同祖先继承的基因。 结果,帮助亲属实际上增加了在利他主义者身上发现的基因复制件传递给下一代的机会。 这样,社会生物学家认为,控制利他主义的基因可以被选择,并增加物种的频率。Criticisms of Sociobiology
::社会生物学批评论Other scientists have criticized sociobiology on several grounds. Critics think that it is not valid to base explanations of human behavior on the behavior of insects. They also criticize the assumption of sociobiologists that genes are more influential than the environment in most behaviors. For example, sociobiologists contend that variation in human behaviors such as aggression (see the Animal Behavior: Aggression (Advanced) concept) can be explained by differences in genes. Most experts on human behavior take the opposite view. They think that variation in aggression and other human behaviors can be explained by differences in environments. They cite evidence showing that environmental factors, such as exposure to violence in the media, can influence how aggressively people behave.
::其他科学家出于多种理由批评了社会生物学。 批评家认为,用昆虫的行为来解释人类行为是不合理的。 他们也批评社会生物学家认为基因在大多数行为中比环境更有影响力的假设。 例如,社会生物学家认为,诸如侵犯等人类行为的差异(见动物行为:侵略(高级)概念)可以用基因差异来解释。 多数人类行为专家持相反的观点。 他们认为,环境差异可以解释侵略和其他人类行为的差异。 他们引用证据表明,环境因素,如媒体中的暴力暴露,可以影响人们的激进行为。Sociobiology has also been criticized for using “just-so” stories to explain animal behavior. A just-so story is an explanation that does not rest on any evidence other than its own internal logic. A just-so story can be created to argue for the adaptiveness and evolution of almost any trait. In fact, different sociobiologists have sometimes explained the same trait with opposite just-so stories. Most of these just-so stories rest on the assumption that behavior is genetically controlled and that it must be adaptive simply because it has not died out. In contrast, critics of sociobiology argue that any explanation of behavior must be based on evidence. The evidence must show that the behavior is genetically controlled and that it results in the production of more offspring.
::社会生物学也因为使用“简单”的故事来解释动物行为而遭到批评。 一个简单的故事是一个解释,它不以任何证据作为依据,而不只是其内部逻辑。一个简单的故事可以用来为几乎任何特性的适应性和进化辩护。事实上,不同的社会生物学家有时用相反的故事来解释同样的特征。这些简单的故事大多基于一种假设,即行为是基因控制的,它必须是适应性的,因为它没有消亡。相反,社会生物学的批评家们则认为,对行为的任何解释都必须以证据为基础。 证据必须表明,行为是遗传控制的,它导致更多的后代的产生。Charles Darwin also invented a few “just-so” stories to explain the evolution of certain organisms . The following example appeared in his book, On the Origin of Species, although he later deleted it: "In North America the black bear was seen...swimming for hours with widely open mouth, thus catching, like a whale, insects in the . Even in so extreme a case as this, ...I can see no difficulty in a race of bears being rendered, by natural selection, more and more in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale."
::查尔斯·达尔文还发明了几个“简单”的故事来解释某些生物的进化。以下的例子出现在他的书《物种起源》中,尽管他后来删除了它:“在北美,人们看到黑熊张开大嘴巴地游荡数小时,从而像鲸鱼一样捕捉昆虫。即使在如此极端的情况下,......我可以看到熊种族的形成毫无困难,因为自然选择,其结构和习惯越来越复杂,其结构和习惯越来越大,而且嘴的大小越来越大,直到动物像鲸鱼一样被生出来。”Summary
::摘要-
Whether behaviors are controlled mainly by genes or by the environment is controversial.
::行为是否主要受基因或环境控制是有争议的。 -
A behavior that is at least partly under genetic control can evolve through natural selection. However, being controlled by genes is not the only requirement for a behavior to evolve through natural selection.
::至少部分受基因控制的行为可以通过自然选择而演变。 然而,受基因控制并不是通过自然选择而演变行为的唯一要求。 -
Sociobiologists assume that behaviors that persist or increase in frequency must be adaptive.
::社会生物学家认为,持续或增加频率的行为必须是适应性的。
Review
::回顾-
What is the major controversy over the origins of animal behavior?
::动物行为起源的重大争议是什么? -
If you were a behavioral scientist, how could you set out to prove that a behavior is controlled by genes?
::如果你是一个行为科学家, 你怎么能去证明 一种行为是受基因控制的? -
How can behaviors evolve through natural selection?
::行为如何通过自然选择而演变? -
What behavior did Darwin think was "actually fatal" to his theory of evolution?
::达尔文认为什么行为 "实际上致命" 对他的进化理论? -
What is one explanation of altruism?
::利他主义的一个解释是什么? -
What are some criticisms that have arisen against sociobiologists?
::社会生物学家受到的批评是什么?
Explore More
::探索更多 -
Whether behaviors are controlled mainly by genes or by the environment is controversial.
