Эволюция и видообразование
International Baccalaureate · IB Diploma · Biology · SL Тема 5 3:59 Английское озвучивание · Английский + китайские субтитры (встроенные)
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Leaves in dry environments often have features that reduce water loss.
干燥环境中的叶片通常具有减少水分流失的特征。
The value of a feature depends on environmental conditions and trade-offs.
某一特征的价值取决于环境条件与权衡关系。
An adaptation is a heritable feature associated with improved survival or reproduction in particular conditions.
适应是指与在特定条件下提高生存或繁殖能力相关的可遗传特征。
A thick cuticle can reduce evaporation; stomatal control affects gas exchange and water loss.
厚角质层可以减少蒸发；气孔控制影响气体交换和水分流失。
Acclimatization is an individual response during life and is different from evolutionary adaptation.
驯化是个体在生命周期内的反应，与进化适应不同。
Adaptation refers to a heritable feature benefiting survival or reproduction in a context.
适应：在特定背景下有利于生存或繁殖的可遗传特征。
Acclimatization refers to an individual adjustment to changed conditions during life.
驯化：个体在生命周期内对变化环境的调整。
Explain both a benefit and a cost.
解释其益处与代价。
Reducing stomatal opening conserves water, but can limit carbon dioxide entry.
减少气孔开度可保存水分，但可能限制二氧化碳进入。
A feature cannot be judged as universally best without its ecological context.
脱离生态背景，无法判定某一特征是否绝对最优。
In the lab: Compare replicated observations across a measured environmental gradient.
在实验室中，比较测量环境梯度上的重复观测结果。
Account for relatedness, leaf area and age.
需考虑亲缘关系、叶面积和年龄因素。
Use local permitted plant observations rather than removing protected species.
使用当地允许的植物观测数据，而非移除受保护物种。
Known: water loss is 12 grams from 0.20 square metres of leaf area over 2 hours.
已知：在 2 小时内，0.20 平方米叶面积的水分流失量为 12 克。
The area-time-normalized rate is 12 divided by the product of 0.20 and 2, which equals 30 grams per square metre per hour.
按面积和时间归一化的速率等于 12 除以 0.20 与 2 的乘积，即每平方米每小时 30 克。
Comparisons require the same humidity and temperature.
比较必须在相同的湿度和温度下进行。
Your turn.
轮到你了。
Water loss is 8 grams from 0.20 square metres over 2 hours.
水分流失量为 8 克，面积为 0.20 平方米，时间为 2 小时。
Calculate the rate per area per hour.
请计算单位面积每小时的流失速率。
An individual organism does not evolve a new inherited trait because it needs it.
个体生物不会仅仅因为需要而进化出新的遗传性状。
A plausible story about function is a hypothesis requiring evidence.
关于功能的合理叙述是一种假说，需要证据支持。
Not true: Every useful individual response is evidence of a newly evolved inherited trait.
这种说法不正确。 并非每一个有用的个体反应都是新进化出的可遗传性状的证据。
Evolution acts on populations over generations through heritable variation and selection.
进化通过可遗传变异和自然选择在种群中跨代发生。
An individual's useful acquired response is not inherited and is not evidence that a new trait evolved.
个体获得的有用反应不可遗传，也不能作为新性状进化的证据。
An adaptation is a heritable feature associated with improved survival or reproduction in particular conditions.
适应是一种可遗传的特征，与在特定条件下的生存或繁殖能力提高有关。
Explain both a benefit and a cost.
请解释其益处和代价。
Watch for: an individual organism does not evolve a new inherited trait because it needs it.
注意：个体生物不会因为它需要而进化出新的遗传性状。
Water loss is nine grams from zero point three square metres over three hours.
水分流失量为9克，面积为0.30平方米，时间为3小时。
Find the rate per area per hour.
求单位面积每小时的流失速率。
One useful response in one individual is not a newly evolved inherited trait.
个体中一种有用的反应并非新进化出的遗传性状。
The result is a rate of 10 grams per square metre per hour.
结果是速率为每平方米每小时10克。
Selection starts from heritable variation.
选择从可遗传的变异开始。
The environment favours some variants, they survive and reproduce more, and the population changes over generations.
环境有利于某些变异个体，它们存活和繁殖得更多，种群因此代代改变。
Fictional plants lose 12 grams from 0.20 square metres in 2 hours, and 9 grams from 0.10 square metres in 3 hours.
虚构植物在2小时内从0.20平方米中损失12克，在3小时内从0.10平方米中损失9克。
Compare normalized rates.
比较归一化速率。
Can this alone prove which is better adapted?
仅凭这些数据能否证明哪一种适应度更好？
Both give 30 grams per square metre per hour.
两者都是每平方米每小时 30 克。
Match humidity, temperature and plant condition; equal recorded water loss is not proof of equal survival or adaptation.
要使湿度、温度和植株状况一致；记录到的失水量相同，并不能证明存活率或适应程度相同。
Repeat with representative samples.
应使用有代表性的样本重复实验。
Pause and check yourself. Explain each point on screen in your own words, then change one number in the last example and say which assumption must still hold.
暂停一下，自我检查：用自己的话解释屏幕上的每个要点，再改动最后一个例子中的一个数字，说明哪个假设仍然必须成立。