Natural selection · 自然选择
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| natural selection/ˈnætʃərəl sɪˈlekʃn/ | 自然选择 | zì rán xuǎn zé |
| competition/ˌkɒmpəˈtɪʃn/ | 竞争 | jìng zhēng |
| evolution/ɪvəˈluːʃn/ | 进化 | jìn huà |
Survival of the fittest
- Why do organisms become so well suited to their environment?
- The answer is natural selection 自然选择 — Darwin's great idea.
适者生存
- 为什么生物变得如此适合它们的环境?
- 答案是自然选择(natural selection)——达尔文的伟大想法。
Put the steps of natural selection in order. · 把自然选择的步骤按顺序排列。
Variation → competition → survival → inheritance. · 变异 → 竞争 → 生存 → 遗传。
Natural selection is often summarised as "survival of the ______". · 自然选择常常被概括为"______生存"。
The best-adapted survive and reproduce. · 最适应的生存和繁殖。
The steps of natural selection
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- Variation: individuals in a species differ.
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- Competition 竞争: more are born than can survive; they compete for resources.
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- Survival: those with helpful features are more likely to survive and reproduce.
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- Inheritance: they pass on the helpful alleles, so the species changes over time.
Natural selection: the best-adapted survive, reproduce and pass on their alleles
自然选择的步骤
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- 变异:一个物种中的个体不同。
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- 竞争:出生的比能生存的多;它们为资源竞争。
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- 生存:那些有有用特征的更可能生存和繁殖。
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- 遗传:它们传递有用的等位基因,所以物种随时间改变。
自然选择:最适应的生存、繁殖并传递它们的等位基因
Natural selection · 自然选择
Individuals best suited to their environment survive and pass on their genes — so the population changes over time. · 最适合它们环境的个体生存并传递它们的基因——所以种群随时间改变。
Antibiotic resistance evolves because: · 抗生素抗性进化,因为:
Selection favours the already-resistant bacteria. · 选择青睐已经有抗性的细菌。
A classic example
- Antibiotic resistance: a few bacteria happen to have a resistance allele.
- Antibiotics kill the rest, the resistant ones survive and multiply — a resistant population evolves.
一个经典的例子
- 抗生素抗性:少数细菌碰巧有一个抗性等位基因。
- 抗生素杀死其余的,有抗性的存活并繁殖——一个有抗性的种群进化出来。
Natural selection · 自然选择
Run the generations: birds eat the moths that stand out, so the camouflaged ones survive and breed — the population shifts to match the forest. · 运行这些世代:鸟吃掉显眼的蛾,所以伪装的存活并繁殖——种群改变以匹配森林。
Over many generations, natural selection leads to: · 经过许多代,自然选择导致:
Allele frequencies shift, changing the species. · 等位基因频率改变,改变物种。
Variation arises randomly; organisms do not choose to adapt. · 变异随机地产生;生物不选择适应。
Mutations are random; selection favours helpful ones. · 突变是随机的;选择青睐有用的。
Evolution 进化
- Over many generations, natural selection causes evolution — a change in a species.
- Helpful alleles become more common; unhelpful ones become rarer.
Organisms don't choose to adapt. Variation arises randomly (by mutation). Natural selection simply favours whichever variations already help survival. Nothing is deciding to change.
进化
- 经过许多代,自然选择引起进化(evolution)——一个物种的改变。
- 有用的等位基因变得更常见;无用的变得更罕见。
生物不选择适应。 变异随机地产生(通过突变)。自然选择只是青睐任何已经帮助生存的变异。没有什么在决定改变。
You've got it
- natural selection: variation → competition → survival of the fittest → inheritance
- helpful alleles are passed on, so the species changes — evolution
- antibiotic resistance is natural selection in action; variation is random, not chosen
你掌握了
- 自然选择:变异 → 竞争 → 适者生存 → 遗传
- 有用的等位基因被传递下去,所以物种改变——进化
- 抗生素抗性是行动中的自然选择;变异是随机的,不是被选择的