The whole idea of evolution is quite simple. Things do change.
When organisms change over lots of generations, they could well be better suited to survive, or not, and likely to die.
Next lesson: Genetic vs. Environmental Traits
This transcript is added for your convenience. To describe what’s going on, scientists use a number of terms.
Natural Selection –There are times that we’ve got skills that help us survive; sometimes we don’t. Suppose you are a 500-pound heavy bird with tiny little wings and tiny little legs, chances are that you couldn’t be moving around so well. There might come a day that you run out of food so you will die. So you were just selected to be extinct.
Well, the lifetime achievement of Charles Darwin is Natural selection. Darwin’s Galapagos Islands work has laid the framework and foundation for our modern-day natural selection theory.
Convergent Evolution –We speak of Convergent Evolution when totally different species are developing similar traits. They came up with a similar or identical solution to any problem but from a totally different direction. It’s not that conscious choices are made for the development of eyes or a certain way of hearing. In fact, natural outside factors are creating situations where certain skills are beneficial.
For example, suppose you are an animal and I am a plant. Both of us have animals hunting and eating us. So we both need protection and both of us are developing spines for poking the hunters. Sure, our spines are made in totally different ways, but in fact, they do exactly the same job. Well, I am a cactus and you are a porcupine.
Divergent Evolution –We speak of Divergent Evolution when our developments begin at one place and later split in different directions. So we begin as identical species, but over time, when more generations have developed, your group gets good at one thing while my group will be good at another.
For this, bird beaks form a nice example. Two species of bird may develop in totally different directions in response to or depending on the type of food they eat. After many generations, their beaks ill have developed different shapes. Charles Darwin was using the development of birds in quite a few of his scientific work and papers.
Coevolution –We speak of Coevolution when over time, two different species will have changed and evolved together. Usually, these species are dependent on each other to be able to survive. Insects and flowers form some good examples of coevolution.
If you take a look at some really fancy orchids, you may notice that they generally are depending on one species of bug for their reproduction efforts. Now, as one of the species will change, the other species will likely make mirror changes in order to be able to survive.