7.2 原始囚犯分类和演变
Section outline
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My, What Big Eyes You Have!
::天啊,你那双大眼睛!This big-eyed little mammal is a lemur. This particular of lemur lives in forests of Madagascar, an island off the eastern coast of Africa. Lemurs like this one are a good way to introduce the fascinating story of the evolution of our own species, Homo sapiens . Like us, lemurs are primates. Other p rimates a re our closest relatives in the , and we share a relatively recent evolutionary history with them. Many of our modern human traits are a product of that evolutionary history. Lemurs are an excellent starting point in the study of our primate origins because they are much more si milar to the earliest primates than we are.
::这个大眼睛的小哺乳动物是狐猴。 这个特殊的狐猴生活在马达加斯加的森林中, 马达加斯加是非洲东海岸的一个岛屿。 像这样的狐猴是一个很好的方法, 来介绍我们自身物种的进化的奇妙故事, 象我们一样, 狐猴是灵长类动物。 其他的灵长类动物是我们的最亲近的亲属, 我们和它们有着较近的进化史。 我们的许多现代人类特征是进化史的产物。 狐猴是研究我们原始起源的极好起点, 因为它们比我们最早期的灵长类动物要相似得多。Introduction to the Primates
::初等囚犯介绍Primates arose from small mammalian ancestors that lived in the trees of tropical forests. Many primate characteristics represent adaptations to life in this challenging, three-dimensional arboreal (tree-living) environment. Most primate species remain at least partly arboreal, and even (ground-living) primates retain adaptations for climbing trees.
::许多灵长类动物特征代表着在这个充满挑战的、三维的Arboreal(树木生活)环境中对生命的适应性。 大多数灵长类物种至少部分保持异种,甚至(地生的)灵长类动物保留着爬树的适应性。Primates are considered generalist mammals. They have a skeletal structure that allows a wide range of motion of the limbs. This is reflected in the diversity of ways that they move around. They may leap, climb, brachiate (swing from branch to branch), walk on all four legs, or walk on two legs. Their relatively unspecialized extremities with long digits and nails (instead of claws) are capable of many different functions — unlike, for example, the more specialized clawed feet of cats or dogs.
::灵长类动物被视为一般哺乳动物,其骨骼结构允许四肢的多种运动,这体现在其行走方式的多样性上,它们可以跳跃、爬跃、摇晃(从树枝到树枝)、四条腿都行走或双腿行走,它们相对没有专门化、长数字和钉子(而不是爪子)的外形可以发挥许多不同功能——例如,与猫或狗更专门的爪脚不同。Primate Classification and Phylogeny
::囚犯的初质分类和生殖法Primates are a very diverse order. There are more than 50 primate genera and hundreds of different species of living primates. New primate species are still being discovered. Dozens of new species of primates have been discovered since the year 2000 alone!
::灵长类是多种多样的顺序。 有50多种灵长类和数百种不同种类的活灵长类。 新的灵长类物种仍在被发现。 数十种新灵长类物种自2000年以来就被发现了!Prosimians and Anthropoids
::百草枯类和人类类The traditional of primates does not necessarily reflect their evolutionary history. It is based mainly on morphological similarities, rather than common ancestors. However, some of the traditional taxa are still commonly used, so it is important to be familiar with them. Primates have traditionally been divided into two major groups, called prosimians and anthropoids (or simians). Prosimians include lemurs (like the one pictured above), lorises, and tarsiers. Anthropoids include monkeys, apes, and humans. Prosimians are generally small in size and have characteristics similar to the earliest primates, whereas anthropoids tend to be larger and less similar to early primates.
::灵长类动物的传统不一定反映其进化历史,它主要基于形态相似,而不是共同祖先。然而,一些传统分类仍然被普遍使用,因此必须熟悉它们。原始人传统上被分为两大类,称为亲善人和人类类(或模拟人 ) , 古代人包括狐猴(如上图所示 ) 、 、 和。 人类类动物包括猴子、猿类和人类。 Prosimian人一般规模小,具有与最早的灵长类相似的特征,而人类类动物则往往更大,与早期的灵长类动物不太相似。Phylogeny
::丙基苯基Today, primates are generally classified on the basis of their evolutionary history. This type of classification is based on a branch of science called phylogeny . It shows how species are related by common ancestors. The tree below shows the phylogeny of primates. For comparison, the traditional classification of primates into prosimians and anthropoids is included at the top of the phylogenetic tree .
::今天,灵长类动物一般根据其进化历史进行分类,这种分类基于称为植物遗传学的科学分支。它显示了物种与共同祖先的关系。下面的树显示了灵长类动物的植物特征。相比之下,将灵长类动物的传统分类列入植物遗传学树顶部。Do you notice a discrepancy between the phylogeny of primates in the tree diagram and the traditional, morphological classification? Tarsiers traditionally were grouped with the prosimian lemurs and lorises, but they are now placed in a separate group. This is because tarsiers shared a more recent common ancestor with anthropoids than did the other prosimians. The phylogenetic classification also shows how New World m onkeys branched off from Old World primates before the latter diverged into Old World monkeys and apes. The word apes is a general term that refers to modern gibbons, orangutans, gorillas, chimpanzees, and humans, as well as their ancestors following the split from Old World monkeys. Based on the phylogenetic tree, who are our closest living relatives? With which group did we share the most recent common ancestor?
::你注意到树形图中灵长类动物的植物与传统形态学分类之间的差异吗?塔塞尔人传统上被与原生狐猴和山丘相组合,但现在却被分成一个单独的组。这是因为塔里西亚人与其他人相比,与人类类动物有较新的共同的祖先。植物基因分类还显示新世界猴子如何从旧世界灵长类动物中分离出来,而老世界灵长类动物在古老世界的猴子和猿类中分裂出来。猿类一词是一个泛泛术语,指现代长猴、猩猩、猩猩、黑猩猩和人类,以及他们在与旧世界猴子分离之后的祖先。基于植物基因树,谁是我们最亲近的亲。我们和哪个组分享了最新的新老祖先?Major Events in Primate Evolution
::最初进进化中的重大事件If you look at the left side of the phylogenetic tree above , you can see approximately how long ago the different groups of primates diverged from their common ancestors.
::如果你看看上面的植物基因树的左侧, 你可以看到大约多久前 不同的灵长类 与他们的祖先不同了。Earliest Primates
::最远世长者Based on and molecular evidence , the first primates may have evolved as early as 55 to 65 million years ago. An early close primate relative — the genus named Plesiadapis — left abundant fossil remains in North America and Europe that date to 55-58 million years ago, but may have originated earlier. Plesiadapis was a small, at least partly arboreal mammal that may have eaten fruits and leaves. This now-extinct genus had a small brain and claws instead of nails. Its were located on the sides of the head, which meant it lacked stereoscopic ( three dimensional ) . With these traits, Plesiadapis itself was not a primate, but it was a likely ancestor of primates.
::根据分子证据,最早的灵长类动物早在5500万到6500万年前就已经演变了。早期的灵长类动物亲戚 — — 名叫Plesiadapis的精灵 — — 在北美和欧洲留下了大量的化石,日期是5500万到5500万年前的,但可能早于5500万年前,起源于北美和欧洲。Plesiadapis是一个小的,至少部分是半生哺乳动物,可能已经吃过水果和叶子。这个现在灭绝的精灵有一个小的大脑和爪子,而不是指甲。它位于头的两侧,这意味着它缺乏立体科(三维 ) 。 有了这些特征,Plesiadapis本身不是原始动物,但它可能是原始动物的祖先。Divergence Within the Primates
::原始囚犯内部的差异Once the first primates emerged, primates continued to evolve until the present. During that long time span, primates underwent a series of evolutionary divergences, in which the major groups of primates branched off and new common ancestors emerged.
::第一个灵长类出现后,灵长类继续演变到现在。 在这漫长的时期里,灵长类经历了一系列进化差异,其中主要灵长类出现,新的共同祖先出现。-
The first major divergence probably occurred close to 60 million years ago, when the lineage that would evolve into modern lemurs and lorises branched off from other early primates.
::第一个重大差异可能发生在接近6 000万年前,当时将演变为现代狐猴和峰叶的世系从其他早期的灵长类动物分离出来。 -
The divergence that led to the tarsiers probably dates to about 55 million years ago. The earliest tarsier-like fossils are found at that time in East Asia.
::导致塔西埃的分歧可能发生在大约5500万年前。 当时在东亚发现了最早的类似塔西埃的化石。 -
The emergence of the common ancestor of all anthropoid primates (modern monkeys, apes, and humans) is thought to have occurred around 40 million years ago, possibly in Asia, as well. If the earliest anthropoids did evolve in Asia, they soon dispersed across Asia into Africa.
::所有人类类灵长类动物(现代猴子、猿类和人类)的共同祖先(现代猴子、猿类和人类)的出现被认为大约发生在4000万年前,也可能发生在亚洲。 如果最早的人类类动物在亚洲真的演变,那么它们很快会散布到亚洲非洲。 -
The group of anthropoids that would evolve into modern New World monkeys probably split from their African ancestors at least 35 million years ago. They traveled from Africa to South America across the Atlantic Ocean, which was much narrower then. Most likely, a few primates were carried out to sea on a natural raft of vegetation, and
were then
carried to the New World by currents.
::将演变为现代新世界猴子的人类类动物群可能至少3500万年前从非洲祖先分裂出来。 它们从非洲到南美洲穿越大西洋,当时范围要窄得多。 很可能,少数灵长类动物被自然的植物木筏送入海洋,然后被海流带到新世界。 -
A possible common ancestor of Old World monkeys, apes, and humans was the genus
Aegyptopithecus,
which lived around 35-33 million years ago. It was
about 56 to 92 cm (22 to 36 in) in length and weighed about 6.7 kilograms (17.7 lb).
Aegyptopithecus
lived in subtropical forests, where it was most likely an arboreal quadruped that fed on fruit.
::古老世界猴子、猿类和人类的一个可能的共同祖先是3,500万到3,300万年前居住的奥努斯阿伊托皮茨人,长约56至92厘米(22至36英寸),体重约6.7公斤(17.7磅),奥伊托皮斯库人生活在亚热带森林中,那里很可能是食用果实的亚生物四倍。 -
The Old World monkeys had diverged from the group that today includes just apes and humans by 23 million years ago. A possible common ancestor of both apes and humans is the species
Proconsul africanus,
which lived about
23 to 14 million years ago. It was probably an arboreal quadruped, meaning that it walked on four limbs and fed mainly on fruit. It had a brain larger than a modern monkey, but not as large as a modern ape.
::旧世界猴子已经脱离了今天仅包括猿类和人类的2300万年前的这一群体。 猿类和人类的一个共同的祖先是2300万到1400万年前的非洲大猩猩物种。 它可能是一个亚伯里亚四倍的物种,这意味着它四肢并主要靠水果为食。 它的大脑比现代猴子大,但不像现代猩猩那么大。 -
Ancestors of gorillas diverged from the apes that would eventually evolve into chimpanzees and humans about eight million years ago in Africa.
Approximately
six million years ago in Africa, the chimpanzee and human lineages finally diverged. The first true human ancestors evolved not long after that. You can read about this period of primate evolution in detail in the concept
Evolution of the Human Family.
::在非洲,大猩猩的祖先与猩猩不同,它们最终会演变成黑猩猩和人类,大约800万年前在非洲。大约600万年前在非洲,黑猩猩和人类的祖先最终会分裂。在那之后不久,第一个真正的人类祖先就进化了。从人类家庭进化的概念中,你可以详细读到这个原始进化时期。
Primate Evolutionary Trends
::初步进进进趋势The main evolutionary trend of primates has been the elaboration of the brain. Comparative studies show a continual trend toward higher intelligence going from prosimians to New World monkeys to Old World monkeys to apes and finally to humans. T he part of the brain that has increased the most is the neocortex , which is the part of the brain involved with sensory perception, generation of motor commands, spatial reasoning, and conscious thought. In human primates, the neocortex is also involved with language. While other mammals rely heavily on their sense of smell , the arboreal life of primates has led to a tactile (touch) and visually-dominant sensory system. At the same time, there has been a reduction in the olfactory (smell-related) parts of the brain.
::灵长类动物的主要进化趋势是大脑的演化。比较研究表明,从原生动物到新世界猴子,到老世界猴子,到猿类,最后到人类,一直有更高的智力趋势。大脑中增加最多的部分是新皮层,这是大脑中与感官感知、运动指令的产生、空间推理和自觉思维有关的部分。在人类灵长类动物中,新皮层也与语言有关。虽然其他哺乳动物在很大程度上依赖嗅觉,但灵长类动物的炭蛋白生命导致了触觉(触摸)和视觉感官系统。与此同时,大脑的嗅觉(与嗅觉有关的)部分也有所减少。With their large brains, primates have advanced cognitive abilities. One indication of this is their tool use. Besides humans, many other species of primates, especially anthropoids, have been observed using items in their environment as tools. The gorilla pictured is using a stick to t est the depth of as she wades through it. Monkeys have been documented cracking nuts by placing them on an "anvil" stone and hitting them with another large stone. Monkeys also use stones to crack open crabs and other shellfish. Some primates make tools, as well. Chimpanzees, for example, strip leaves from twigs and insert the twigs into termite mounds to "fish" for edible . They also sharpen sticks to use as spears for hunting small mammals.
::以他们的大大脑,灵长类动物具有先进的认知能力。其中的一个标志就是他们使用的工具。除了人类以外,还观察到许多其他种类的灵长类动物,特别是人类类动物,在他们的环境中以物品作为工具。大猩猩的图象是用一根棍子来测试它穿过它时的深度。猴子被记录成裂纹,把他们放在一个“安维尔”的石头上,用另一块大块石头击打它们。猴子还用石头来敲碎开的螃蟹和其他贝类。有些灵长类动物制造工具。例如,黑猩猩,从树枝上脱落叶,把树枝插入白蚁丘中,作为“鱼”的食用。它们还磨亮棍子作为猎捕小哺乳动物的矛。Another trend in primate evolution has been an increasing dependence on complex . Primates are among the most social of animals. They live in mated pairs, small family groups, or groups of up to dozens of individuals. Cooperation within the group helps to ensure that all group members survive. Cooperative social behaviors include grooming, food sharing, and collective defense against predators or of territory.
::灵长类进化的另一个趋势是日益依赖复杂的动物。 原始人是最社会性的动物之一,他们生活在配对、小家庭群体或多达数十人的群体中。 群体内的合作有助于确保所有群体成员的生存。 合作的社会行为包括培养、食物共享、集体防御掠食者或领地。Summary
::摘要-
Primates are an order of generalist mammals with adaptations for an arboreal lifestyle that first evolved from small mammalian ancestors about 55-65 million years ago.
::原生动物是普通哺乳动物的顺序,可适应在大约5500万到6500万年前由小型哺乳动物祖先最初形成的非生物性生活方式。 -
The primate order is diverse, with hundreds of living species. Primates have traditionally been classified into two major groups on the basis of morphology: prosimians (lemurs, lorises, and tarsiers) and anthropoids (monkeys, apes, and humans). Modern prosimians are smaller and more
similar to
early primates than the anthropoids are.
::灵长类物种种类繁多,有数百种活种。 世长类动物传统上根据形态学分为两大类:先质类动物(莱穆尔、露天和焦油类)和人类类动物(猴子、猿和人类 ) 。 现代人比人类类动物更小,更类似于早期的灵长类动物。 -
Primate phylogeny classifies primates on the basis of their evolutionary history, according to molecular similarities.
Phylogenetic classification places tarsiers in a separate group from the prosimians, and shows that New World
m
onkeys diverged from Old World anthropoids before the latter diverged into Old World
m
onkeys and apes.
::根据分子的相似性,根据进化历史对原始动物进行原始植物分类。 细胞基因分类将焦耳分解成一个与原生动物不同的群体,并表明新世界猴子与老世界类人猿不同,而老世界类人猿则与老世界类人猿和猿不同。 -
The main evolutionary trend in primates has been the elaboration of the brain, especially the neocortex. The advanced cognitive abilities of primates are
evident
in their ability to use and make tools. Another evolutionary trend in primates has been an increasing dependence on complex social behavior.
::灵长类人的主要进化趋势是大脑的发育,特别是新皮层。 灵长类人的先进认知能力从其使用和制造工具的能力中显而易见。 灵长类人的另一个进化趋势是日益依赖复杂的社会行为。
Review
::回顾1. Demonstrate with a specific example why primates are considered generalist mammals.
::1. 以一个具体的例子说明灵长类动物为何被视为一般哺乳动物。2. Compare and contrast prosimians and anthropoids.
::2. 比较和对比活性动物和人类。3. Why are tarsiers no longer considered prosimians?
::3. 为什么撒油者不再被视为伪善者?4. Outline the sequence and timing of the major divergences within the primate lineage.
::4. 概述灵长类中主要差异的顺序和时间。5. Identify the following genera and their place in primate evolution: Plesiadapis, Aegyptopithecus, and Proconsul.
::5. 确定下列基因组及其在灵长类进化中的位置:普列西阿达皮斯、阿伊斯蒂托皮特克斯和普罗康苏尔。6. Describe the functions of the neocortex that were elaborated during primate evolution.
::6. 描述在灵长类演变过程中阐述的新皮层的功能。7. Give examples of tool-making in nonhuman primates.
::7. 举例说明非人类灵长类动物的工具制造。8. Why has the evolution of complex social behavior been adaptive in primates?
::8. 为什么复杂的社会行为演变对灵长类有适应性?9. Use the phylogeny diagram above to answer the following questions:
::9. 使用上面的植物图解回答下列问题:a. Which are most closely related (i.e. have the most recent common ancestor) to gorillas: humans or Old World monkeys?
::a. 哪些与大猩猩(人类还是老世界猴子)关系最密切(即有最新的共同祖先)?b. Approximately when did the gibbon line split off from the line of primates that eventually produced humans?
::b. Gibbon线大约何时从最终产生人类的灵长类的灵长类中分离出来?c. Which evolved first: the primate line that evolved into Old World monkeys or the line that evolved into New World monkeys?
:c) 哪些是先进的:进化成老世界猴子的灵长类或进化成新世界猴子的灵长类?
d. According to this diagram, what is our closest primate relative?
::d. 根据这个图表,我们最接近的灵长类人的亲属是什么?10. True or False: Tarsiers are anthropoids.
::10. 真实或假:塔塞尔人是人类。11. True or False: There is fossil evidence of early primates in Asia.
::11. 真实或假:亚洲有早期灵长类动物的化石证据。12. True or False: Lemurs are simians.
::12. 真实或假:狐猴是模拟人。13. What region of the brain is reduced in primates compared to other mammals? Why is this not a problem for primates?
::13. 与其他哺乳动物相比,哪个大脑的灵长类动物区域减少? 为什么对灵长类动物来说这不是一个问题?Explore More
::探索更多You may be aware that humans and chimpanzees share 99 percent of their DNA . Check out this video to learn more:
::你也许知道人类和黑猩猩 分享了他们的DNA的99%。Watch this video to see chimpanzees make tools:
::观看这段影片以观看黑猩猩制作工具: -
The first major divergence probably occurred close to 60 million years ago, when the lineage that would evolve into modern lemurs and lorises branched off from other early primates.
