Variations in Populations · 群体中的变异
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| continuous variation/kənˈtɪnjuːəs ˌveərɪˈeɪʃn/ | 连续变异 | lián xù biàn yì |
| discontinuous variation/dɪskənˈtɪnjuːəs ˌveərɪˈeɪʃn/ | 不连续变异 | bù lián xù biàn yì |
No two the same
- Look at any group of the same species and you see differences.
- People differ in height, blood group, eye colour, and much more.
- These differences within a population are its variation.
- And variation comes in two distinct patterns.
没有两个相同
- 看任何一群同种生物,你都会看到差异。
- 人在身高、血型、眼睛颜色以及更多方面各不相同。
- 种群内的这些差异就是它的变异。
- 而变异有两种不同的模式。
Continuous variation
- Continuous variation 连续变异 covers a smooth range of values.
- Height and body mass are examples — every value in between is possible.
- Plotted on a graph, it forms a smooth bell-shaped spread.
- This kind usually comes from many genes together, plus the environment.
连续变异
- 连续变异(continuous variation)覆盖一个平滑的数值范围。
- 身高和体重是例子——中间的每个值都有可能。
- 画在图上,它形成一个平滑的钟形分布。
- 这一类通常来自许多基因共同作用,加上环境。
Continuous variation describes a trait that… · 连续变异描述一个……的性状。
Continuous variation covers a smooth range of values, like height or mass — usually many genes plus environment. · 连续变异覆盖一个平滑的数值范围,比如身高或质量——通常是许多基因加上环境。
Discontinuous variation
- Discontinuous variation 不连续变异 falls into distinct categories.
- Blood group is A, B, AB, or O — nothing in between.
- Whether you can roll your tongue is a yes-or-no trait.
- This kind is usually controlled by just one or a few genes.
不连续变异
- 不连续变异(discontinuous variation)落入不同的类别。
- 血型是 A、B、AB 或 O——中间没有别的。
- 你能不能卷舌是一个是或否的性状。
- 这一类通常只由一个或几个基因控制。
Discontinuous variation describes a trait that… · 不连续变异描述一个……的性状。
Discontinuous variation falls into clear categories, like blood group — usually one or a few genes. · 不连续变异落入清楚的类别,比如血型——通常是一个或几个基因。
Why variation matters
- Variation is the raw material that natural selection acts on.
- If every individual were identical, selection could not favour any of them.
- Genetic variation can be passed on; environmental differences cannot.
- So heritable variation is what lets populations evolve.
变异为什么重要
- 变异是自然选择所作用的原材料。
- 如果每个个体都相同,选择就无法青睐它们中的任何一个。
- 遗传的变异能被传下去;环境的差异不能。
- 所以可遗传的变异,就是让种群进化的东西。
Continuous or discontinuous? · 连续还是不连续?
Sort each trait by whether it varies over a smooth range or falls into distinct categories. · 按照每个性状是在一个平滑范围内变化,还是落入不同的类别,给它们分类。
Continuous variation is usually caused by many genes together, plus the environment. · 连续变异通常由许多基因共同引起,加上环境。
Many genes adding up (polygenic) plus environmental effects give a smooth range — continuous variation. · 许多基因相加(多基因)加上环境效应,给出一个平滑的范围——连续变异。
Variation within a population is the raw material that natural ____ acts on. · 种群内的变异是自然____所作用的原材料。
Without variation, natural selection would have no differences to favour. · 没有变异,自然选择就没有可青睐的差异。
Select all · 所有 true statements about variation. · 选出关于变异的所有正确说法。
Much variation is genetic, not just environmental. The other three are correct. · 许多变异是遗传的,不只是环境的。其余三条正确。
The two patterns have different causes. Continuous variation comes from many genes adding up, strongly shaped by the environment. Discontinuous variation comes from one or a few genes and is barely affected by the environment. Match the pattern to its cause.
这两种模式有不同的原因。连续变异来自许多基因相加,受环境强烈塑造。不连续变异来自一个或几个基因,几乎不受环境影响。把模式与它的原因对应起来。
Height versus blood group:
- Height is continuous: people range smoothly from short to tall, shaped by many genes and by nutrition.
- Blood group is discontinuous: you are exactly A, B, AB, or O, set by a single gene.
- Same person, two completely different patterns of variation.
身高对比血型:
- 身高是连续的:人从矮到高平滑地分布,由许多基因和营养塑造。
- 血型是不连续的:你恰好是 A、B、AB 或 O,由单个基因决定。
- 同一个人,两种完全不同的变异模式。
Variation within a population comes in two patterns. Continuous variation is a smooth range (like height), caused by many genes plus the environment. Discontinuous variation falls into distinct categories (like blood group), controlled by one or a few genes. Heritable variation is the raw material for natural selection.
种群内的变异有两种模式。连续变异是一个平滑的范围(比如身高),由许多基因加上环境引起。不连续变异落入不同的类别(比如血型),由一个或几个基因控制。可遗传的变异是自然选择的原材料。