进化随着时间而变化。在这个广义的定义下，进化可以指随着时间的推移发生的各种变化 – 山脉的抬升，河床的徘徊或新物种的创造。然而，要了解地球上的生命历史，我们需要更具体地说明我们正在谈论的一段时间内的变化。这就是生物进化这个术语的用武之地。生物进化是指生物体内发生的随时间的变化。对生物进化的理解 – 生物体随时间变化的方式和原因 – 使我们能够了解地球上的生命历史。它们理解生物进化的关键在于一个被称为下降和修改的概念。生物从一代传到下一代。后代从父母那里继承了一套遗传蓝图。但这些蓝图绝不会完全从一代复制到下一代。每一代人都会发生很少的变化，随着这些变化的积累，生物体会随着时间的推移而变化越来越大。随着时间的推移，经过修改的下降会重塑生物，并且会发生生物进化。地球上的所有生命都有着共同的祖先。与生物进化有关的另一个重要概念是地球上的所有生命都有一个共同的祖先。这意味着我们星球上的所有生物都来自一个生物体。科学家们估计，这个共同的祖先生活在350亿到38亿年前，所有曾经居住过我们星球的生物在理论上都可以追溯到这个祖先。分享共同祖先的意义非常显着，意味着我们都是堂兄弟 – 人类，绿海龟，黑猩猩，帝王蝶，糖枫，遮阳伞蘑菇和蓝鲸。生物进化发生在不同的尺度上。进化发生的尺度可以大致分为两类：小规模生物进化和大规模生物进化。小规模的生物进化，更好地称为微进化，是生物群体内基因频率的变化，从一代到另一代。广泛的生物进化，通常被称为宏观进化，是指物种在许多世代中从共同的祖先到后代物种的进展。
Evolution changes over time. In this broad definition, evolution can refer to various changes that occur over time – the uplift of mountains, the ripples of riverbeds, or the creation of new species. However, to understand the history of life on Earth, we need to be more specific about the changes we are talking about over time. This is where the term biological evolution comes into play. Biological evolution refers to changes in the body that occur over time. Understanding of biological evolution – the way and reason why organisms change over time – enables us to understand the history of life on Earth. The key to understanding biological evolution lies in a concept called decline and modification. The creatures pass from one generation to the next. The offspring inherit a set of genetic blueprints from their parents. But these blueprints will never be completely copied from one generation to the next. There are very few changes in each generation, and as these changes accumulate, the organisms will change over time. Over time, a modified decline will reshape the creature and biological evolution will occur. All life on earth has a common ancestor. Another important concept related to biological evolution is that all life on Earth has a common ancestor. This means that all the creatures on our planet come from an organism. Scientists estimate that this common ancestor lived between 35 billion and 3.8 billion years ago, and all the creatures that once lived on our planet can theoretically trace back to this ancestor. The significance of sharing a common ancestor is very significant, meaning that we are all cousins – humans, green turtles, chimpanzees, monarch butterflies, sugar maples, parasol mushrooms and blue whales. Biological evolution takes place on different scales. The scale of evolution can be roughly divided into two categories: small-scale biological evolution and large-scale biological evolution. Small-scale biological evolution, better known as micro-evolution, is the change in gene frequency within a biological population, from one generation to another. Extensive biological evolution, often referred to as macroscopic evolution, refers to the progression of species from common ancestors to offspring species in many generations.